Point/Counterpoint: DOHC v OHV

[XfireZ51]

As owners of the Hyphened ZR, a great part of our attraction involves the sensation emanating from the turbine like feel of the LT-5 motor. So I have started this thread to devote a space to the yin and yang of engine architecture.
My premise is that GM has done a marvelous job of optimizing the OHV architecture. BUT, I think we're seeing the end of the road for "the little engine that could". The LT-5 represented an alternative that GM abandoned 25 years ago bu that our small community continues to push forward and give a glimpse of what might have been. Just sayin!

[Kevin]

Our cars a relic, sure we've done a great job of moving them forward but we're still dealing with something designed and built in the late 1980's. The ease of tuning and modding the lsx is something we can only dream of. The zr-1 had it's time of being king and sadly it's over, but that's to be expected. Time marches on, and that's the way it should be. There are two main things keeping from from jumping into a c6z06. OHC and the interior.

[mike100]

I still value the simplicity and lower weight of the OHV engine, but i usually prefer to drive my lt5 or coyote mustang 5.0 over my LS3 car. I think it just has the extended torque delivery if you need a single simple answer of why dohc is best. I think the question really is going to be about all future engines having a turbo charger and electric assist to cope with emissions. The days of a factory 8000 rpm NA screamer may be over.

I'm over in Europe at the moment and had a chance to drive some 50 mpg cars w turbos. Just about everything will be turbo soon if i had to guess.

[XfireZ51]

Audi is introducing electric turbos which should be a game changer. Interesting Mike that you have the opportunity to get SOTP character from the two platforms. A 5300rpm torque peak with long gear pulls onto a highway makes even a simple drive around fun.

[RICKYRJ1]

I cant contribute much on the tech side of this conversation, but on a emotional side I can tell you I love this engine relic or not. Mine has over 500hp, runs great, I get to run it to a high rev, sounds great, bullet proof construction and looks like a piece of art. Do I wish it was cost effective to make more power? of course! we all do. I enjoy also owning a piece of automotive history. I find that guys that know cars, not so much the Corvette guys, but the higher end players know and respect our ZR-1. I appreciate this groups constant effort to push the performance envelope. :saluting:

[edram454]

Having sold my supercharged c5 ls motored car, I dont miss it at all. It made more power than my z will ever make but it was just another cookie cutter corvette at a car show. a dime a dozen. as for as the ls7 z06 is not bullet proof. I have seen a few of these cars throw rods and lose oil pressure in recent weeks. there is one sitting at SGC right now without oil pressure. It seems like its not such a surprise for those who know about them. The ls2 and ls3 are not impressive to me. Im not even impressed with the lt4 in the new z06. It is not a hard charger and if it wasnt for the state of the art suspension and aerodynamics and brakes and light weight, that car would have its butt kicked by other comparable hi end muscle cars like the dodges, fords, etc.. Owning a piece of history and feeling the hard charging acceleration of the LT5 is a joy to behold. It may not be the King but it still holds its own especially in the open road. The ZR-1 is not a drag car, road racer, it is a GT. A car that can do well in all types of racing but excels in high speed runs with endurance in mind.

ed ramos #3028

[KILLSHOTS]

Having sold my supercharged c5 ls motored car, I dont miss it at all. It made more power than my z will ever make but it was just another cookie cutter corvette at a car show. a dime a dozen. as for as the ls7 z06 is not bullet proof. I have seen a few of these cars throw rods and lose oil pressure in recent weeks. there is one sitting at SGC right now without oil pressure. It seems like its not such a surprise for those who know about them. The ls2 and ls3 are not impressive to me. Im not even impressed with the lt4 in the new z06. It is not a hard charger and if it wasnt for the state of the art suspension and aerodynamics and brakes and light weight, that car would have its butt kicked by other comparable hi end muscle cars like the dodges, fords, etc.. Owning a piece of history and feeling the hard charging acceleration of the LT5 is a joy to behold. It may not be the King but it still holds its own especially in the open road. The ZR-1 is not a drag car, road racer, it is a GT. A car that can do well in all types of racing but excels in high speed runs with endurance in mind.

ed ramos #3028
What? What is a "hard charger" and why is the Z06 not one? Which of "the dodges, fords, etc." would be kicking the Z06's butt, were it not for its suspension and aerodynamics? Can you cite any example of a "comparable hi end muscle car"? Are you speaking of the yet-to-be-released GT350 Mustang, or the 1/4-mile-only Hellcats? Could either of those truly be described as "comparable" to the Z06?

The LT5 is a brilliant engine on its own merits; diminishing the LT4 does not elevate it.

[edram454]

Well, two weekends ago I went to the Homestead Nascar track that is 1 mile from my house and they were running all types of cars during a track day event. there were two brand new Z06's on the track too. It seemed like everything passed those cars up. I saw a fox body Mustang with a coyote engine consistently trash the z06's lap after lap. I saw BMWs, mercedes, vipers, etc.. an endless list of cars trashing the z06's lap after lap. A couple of fridays a month they have 1/8 mile nights at the tracks pit road. I saw a new z06 participating and saw a Dodge Challenger Hellcat kill it in the eight mile and another viper trash it too. A modded c6 killed it along with a modded c5 z06. The new z06 cant even top 200 miles per hour while a c6 zr1 can do 209 miles per hour.

If I had a top tier car like any of the ones I mentioned I would not back down to a new z06. Maybe in hard twisties or a tight road course that requires constant severe braking I would not test a z06 but at speed events I would. I am not downing the lt4 to elevate an lt5. it is no comparison 375hp to 650?? I would have liked chevrolet to have thrown the gauntlet and put something out there at least making 700 horse. The mustang had made the super snake 750hp for years and now the hellcats etc...

The hard charger is what a dohc hi performance v8 feels like...it just does not lay down after most cam in block v8's have reached there 6000rmp.. seems like the dohc cars just want to keep on going thus it gives the feeling of a hard charger or constantly accelerating.

I appreciate the handling, braking and down force aerodynamics the z06 bring to the table but am not impressed with its brute power and alot of other competitors arnt either.

ed ramos #3028

[KILLSHOTS]

Well, two weekends ago I went to the Homestead Nascar track that is 1 mile from my house and they were running all types of cars during a track day event. there were two brand new Z06's on the track too. It seemed like everything passed those cars up. I saw a fox body Mustang with a coyote engine consistently trash the z06's lap after lap. I saw BMWs, mercedes, vipers, etc.. an endless list of cars trashing the z06's lap after lap. A couple of fridays a month they have 1/8 mile nights at the tracks pit road. I saw a new z06 participating and saw a Dodge Challenger Hellcat kill it in the eight mile and another viper trash it too. A modded c6 killed it along with a modded c5 z06. The new z06 cant even top 200 miles per hour while a c6 zr1 can do 209 miles per hour.

If I had a top tier car like any of the ones I mentioned I would not back down to a new z06. Maybe in hard twisties or a tight road course that requires constant severe braking I would not test a z06 but at speed events I would. I am not downing the lt4 to elevate an lt5. it is no comparison 375hp to 650?? I would have liked chevrolet to have thrown the gauntlet and put something out there at least making 700 horse. The mustang had made the super snake 750hp for years and now the hellcats etc...

The hard charger is what a dohc hi performance v8 feels like...it just does not lay down after most cam in block v8's have reached there 6000rmp.. seems like the dohc cars just want to keep on going thus it gives the feeling of a hard charger or constantly accelerating.

I appreciate the handling, braking and down force aerodynamics the z06 bring to the table but am not impressed with its brute power and alot of other competitors arnt either.

ed ramos #3028
You haven't mentioned a single comparable vehicle...only anecdotal examples of highly modified track cars. ANYTHING can be modded. Too bad Chevy stopped at only 650 horsepower; they must be saddened to hear that if they'd just given the LT4 an additional 50 ponies, they could have met your lofty standards.

Perhaps you could name some other PRODUCTION vehicles that are capable of reaching 60 miles per hour from rest in less than 3 seconds, clearing the 1/4 mile in less than 11 seconds, AND completing a lap of the Nurburgring in less than 7 minutes.

[XfireZ51]

Guys,

The idea of the thread was to offer viewpoints re: the engine architectures. Let not take things in a personal direction.
Also, I don't think there has been any indication that a Z06 has gone anywhere near sub 7min at the Ring.

[edram454]

It is certainly not personal with me. I call it as I see it. I will not defend a lousy lt4 car. Its a good car, not a super car. All those vehicles are direct comparisons in specific cases. The ls platform is good no question. i just think chevy fell short on the lt4. what about the ones that just blow up after 10 miles?? I have heard of a couple of those. I just feel no way in hell can a lt4 run 24 hours and average 176mph or complete the 200 hour durability test the lt5 had to endure and survive. 200 hours of flooring the beast time after time again and live. some of these lt4's cant even survive 10 miles of parking lot driving. any way it is just my opinion. by the way the nurburgring vette was involved in a crash so the time was not reported. dont take anything personal it is just my opinion. I have had 7 corvettes but have not bought a new c7 even though it is a nice car and the interior is best improvement. I would wait for the next rendition of the lt4 to see if the improvement made warrants super car status. All corvettes are nice but just a little critical of the so called top vette. long live dohc cars. At least Ford got it right with the coyote!

ed ramos #3028

[KILLSHOTS]

Guys,

The idea of the thread was to offer viewpoints re: the engine architectures. Let not take things in a personal direction.
Also, I don't think there has been any indication that a Z06 has gone anywhere near sub 7min at the Ring.
You are correct about the lap time. I had scanned the story but had not read it completely. Although there are reports of the 2015 Z06 with Z07 package having run a 7:08, a 7:06 and a 6:59, GM will not confirm these reports and on closer examination, I haven't been able to find any confirmed time for the car. Apparently, the Nurburgring has placed a temporary ban on "official" lap times for some reason, so the car is probably running these times, but GM is playing by the 'Ring rules and not sanctioning them. On a speculative basis, a 7-minute lap doesn't seem out of the question to me, since a C6 Z06 ran a 7:22.

[Paul Workman]

Perhaps a more objective analysis could be attained by considering dyno results; in particular "power under the curve".

That said, it is worth mentioning an analysis of results would show the (FBI) ZR-1s produced the fastest 3-car team aggregate 5* out of 6 attempts at the local Crown Point Corvette Club's annual Corvette Shootouts*. The event is made up of Chicago area Corvette clubs, and has been flooded with LSx's, and last fall a couple new LTx's. Various videos showed time and time again the lighter LSx cars jumping out front off the line, but at the 1/8 point the ZR-1s had reeled them in and beating them at the "top end".

*The Team Trophy was not awarded to the ZR-1 team on two occasions; one year the ZR-1s were not registered for trophy runs (but time slips showed they would have won had they been registered), and (for one year only) the trophy was tied into bracket racing rules instead of the aggregate speed of the top 3 club cars.

Analysis of the last two WANNA GO FAST events in Chicago clearly shows two things: 1) Forced induction dominated the 264 cars participating in the (2014) event, and the top 45 out of 264 speeds were all forced induction (with one possible exception), and a good number of them used the DOHC architecture. (See list below)

WANNAGOFAST Monee, IL 6-21,22, 2014:

Nissan GT-R Alpha 16 (Twin Turbo)
2006 Dodge Viper (Nth Moto) (Twin Turbo)
Nissan GT-R Alpha 16 (Twin Turbo)
Nissan GT-R Alpha Omega (Twin Turbo)
2011 Lamborghini Gallardo Superleggera (Twin Turbo)
Nissan GT-R (Twin Turbo)
Nissan GT-R (Twin Turbo)
Mercedes-Benz E63 AMG (Twin Turbo)
2012 Nissan GT-R (Twin Turbo)
1994 Toyota Supra (Turbo)
Nissan GT-R Alpha (Twin Turbo)
2008 Porsche 997 Turbo (Twin Turbo)
2006 Dodge Viper (Twin Turbo)
2009 Nissan GT-R (Twin Turbo)
Toyota Supra (Turbo)
Toyota Supra (Turbo)
2000 Pontiac Trans-Am (Turbo)
Mitsubishi Evo 2 (Turbo)
2010 Nissan GT-R (Twin Turbo)
1997 Toyota Supra (Sound Performance) (Turbo)
2013 Nissan GT-R Black Edition (Alpha) (Twin Turbo)
1985 Oldsmobile Cutlass (Turbo)
2011 Cadillac CTS-V (Vengeance) (S/C)
2006 Lamborghini Gallardo (Heffner/Nth Moto) (Twin Turbo)
2006 Chevrolet Cobalt SS (Turbo)
C5 Corvette (N/A)
2012 Nissan GT-R (Twin Turbo)
2012 Chevrolet Corvette ZR-1 (S/C)
2004 Lamborghini Gallardo Heffner (Twin Turbo)
2010 Corvette ZR-1 (S/C)
2009 Chevrolet Corvette (S/C)
Mercedes-Benz SLS AMG Black Series (F/I)
2009 Chevrolet Corvette ZR-1 (S/C)
2006 Dodge Viper (Twin Turbo)
1993 Mitsubishi 3000GT VR-4 (Turbo)
Nissan GT-R (Twin Turbo)
1998 Chevrolet Corvette (Tigershark) (Turbo)
Dodge Viper (S/C)
2006 Dodge Viper (Twin Turbo)
Nissan GT-R (Twin Turbo)
Nissan 300ZX (Turbo RB26)
2000 Honda S2000 (Turbo)
2003 Chevrolet Corvette (S/C)
2008 Porsche 911 Turbo (Twin Turbo)
1993 Toyota Supra (Turbo)

There's little doubt the 4-valve DOHC architecture has significant advantages over OHV (pushrods), at least in some venues.

Car and Driver article: DOHC vs. OHC:

http://www.caranddriver.com/columns/pushrods-versus-overhead-cams-part-38-modern-v-8s-from-gm-and-amg-slug-it-out

But that said, where the DOHC architecture has a performance advantage, equally evident is the $/hp advantage of the OHV approach.

Mitigating factors?

Kevin makes a good point regarding technological advances. But, his insinuating that (peak?) hp/$ is the quintessential approach to analysis dismisses other virtues that other architectures (DOHC) have, e.g., power under the curve (for one!). How about durability or driveability?

And, so it goes...

[Mystic ZR-1]

Indy 1994
Roger Penske found a loop hole in the Indy rules and
with Mercedes/Illmor built a 209 cubic inch turbo OHV, 2 valve per cylinder, V8
running 1.86 bars abs of boost (that's about 12.6 pounds, not really a big number
in the serious turbo world, a pure race motor, not a stock block...)
that knocked it out of the park! Pole and race win.
Some estimates were over 1100 hp in qualifying trim!
That's about 5hp/cu in!
Rules allowed a little more boost and a few more cubes for OHV motors.
OHV/DOHC???

[Kevin]

It is certainly not personal with me. I call it as I see it. I will not defend a lousy lt4 car. Its a good car, not a super car. All those vehicles are direct comparisons in specific cases. The ls platform is good no question. i just think chevy fell short on the lt4. what about the ones that just blow up after 10 miles?? I have heard of a couple of those. I just feel no way in hell can a lt4 run 24 hours and average 176mph or complete the 200 hour durability test the lt5 had to endure and survive. 200 hours of flooring the beast time after time again and live. some of these lt4's cant even survive 10 miles of parking lot driving. any way it is just my opinion. by the way the nurburgring vette was involved in a crash so the time was not reported. dont take anything personal it is just my opinion. I have had 7 corvettes but have not bought a new c7 even though it is a nice car and the interior is best improvement. I would wait for the next rendition of the lt4 to see if the improvement made warrants super car status. All corvettes are nice but just a little critical of the so called top vette. long live dohc cars. At least Ford got it right with the coyote!

ed ramos #3028

lt5's were popping in the BG parking lot. No company is perfect and the lt5 is far from it. Is GM worse then most others, I tend to say yes. There's a reason I didn't even look at a gm for my last two daily drivers. I'd still buy a c6z06 tomorrow if I could.

[Paul Workman]

lt5's were popping in the BG parking lot.

WHAT are you talking about, Kevin:confused:

[edram454]

Kevin is probably referring to the time a young lady in charge of starting the zr-1's and parking them after assembly, would start them in the freezing cold and rev them up big time without warming up the car and thus caused damage with the cam chains etc... they stopped lt5 production for a while until they found out what was being done. The young lady said that is the way she started up her car in the morning so she did the same with these brand new zr1 lt5 dohc cars. These motors were tested in practically every condition except the ultra high revving in the freezing cold. That was the only episode a lt5 blew up in the parking lot. No other v8 had to endure the 200 hour durability test in order for it to be installed and sold in gm cars. I really dont think many lsX engines can withstand 200 continual hours of floorings...I would bet on that. lt5's are not perfect but they are durable and they do make power and they dont really on power adders to make power.

As far as the z06, I like them very much. Unfortunately I have seen recently quite a few having major engine failure. I have talked to very knowledgeable people in the corvette world and they say they are not surprised. It happens more than people know. I love the ls7 427 but now I would be hesitant to buy one. Maybe its there owners abusing them or not maintaining them properly?? who knows.. What I do know is that they are not as durable as an LT5. I am a big fan of the ls7, very big fan and it has been depressing to see some of them lose engine oil pressure. I like thels7 better than the lt4 because of its torque and its natural power.

ed ramos #3028

[XfireZ51]

If anyone has any doubt, I would take a C7Z in a New York second. The car is a technological tour de force. It's amazing what GM has done chassis wise to rival much more expensive hardware. Stuff like the E-Diff is awesome.
I'd love to speculate on what's going in back of the rumored mid-engine tho.

[KILLSHOTS]

Kevin is probably referring to the time a young lady in charge of starting the zr-1's and parking them after assembly, would start them in the freezing cold and rev them up big time without warming up the car and thus caused damage with the cam chains etc... they stopped lt5 production for a while until they found out what was being done. The young lady said that is the way she started up her car in the morning so she did the same with these brand new zr1 lt5 dohc cars. These motors were tested in practically every condition except the ultra high revving in the freezing cold. That was the only episode a lt5 blew up in the parking lot. No other v8 had to endure the 200 hour durability test in order for it to be installed and sold in gm cars. I really dont think many lsX engines can withstand 200 continual hours of floorings...I would bet on that. lt5's are not perfect but they are durable and they do make power and they dont really on power adders to make power.

As far as the z06, I like them very much. Unfortunately I have seen recently quite a few having major engine failure. I have talked to very knowledgeable people in the corvette world and they say they are not surprised. It happens more than people know. I love the ls7 427 but now I would be hesitant to buy one. Maybe its there owners abusing them or not maintaining them properly?? who knows.. What I do know is that they are not as durable as an LT5. I am a big fan of the ls7, very big fan and it has been depressing to see some of them lose engine oil pressure. I like thels7 better than the lt4 because of its torque and its natural power.

ed ramos #3028
The difference is the internet. We've heard about an isolated number (3, maybe?) of LT4 failures because those of us who pay attention to these things have instantaneous access to such info now due to the existence of the worldwide web. The reason we didn't hear about it back then was because we lacked the instant access to EVERYTHING that we have today, but even the nearly-bulletproof LT5 had its share of failures when new. Because of this, I have decided to FEEL that the LT5 could not withstand a 200-hour durability test, and I have also decided to FEEL that there's no way it could have run 24 hours straight at nearly 176 MPH.

[Mystic ZR-1]

.......EVERYTHING that we have today, but even the nearly-bulletproof LT5 had its share of failures when new. Because of this, I have decided to FEEL that the LT5 could not withstand a 200-hour durability test, and I have also decided to FEEL that there's no way it could have run 24 hours straight at nearly 176 MPH.

And I suppose you FEEL Elvis and Hitler are still alive? ;)

[KILLSHOTS]

And I suppose you FEEL Elvis and Hitler are still alive? ;)
As I'm sure you can tell, I'm simply illustrating the absurd by being absurd. FEELING that a certain engine is reliable - or that a certain one isn't so - does not make said feeling even remotely true.

[Meanmyz]

I don't really have time write, but will punch this out now anyhow...

I just got back from Arnold, Nebraska on Sunday night. This is the area where the Sand Hills Open Road Challenge was held as well as the Loup to Loup road race. They also had half mile and one mile shootouts.

The winner of the one mile was a modified 2004 Lamborghini putting out 2000 HP. It ran a best of 228 mph through the mile. ...that is another story.

There were three ZR-1's running. They were all modified 350's and I am not sure to which degree. One '90 ZR-1 had Marc's 350/510 package...his actually said 350/515. I believe his one mile run was at 160 mph... that was on older Borla mufflers. The others averaged around 157 mph.

There were three new C7 Z06's there with very experience drivers. A friend of mine had one of them and it has the Z07 package. He had removed the rear wicker extensions from his spoiler.

His car was the fastest of the new Z06's. What did he run??? He was around 165 mph through the mile! He was only five miles per hour faster than the fastest ZR-1!

The stock C6 ZR1's ran faster than the new Z06's.

That is not a put down to the Z06, but there are some issues out there yet for the new car. The Z06 drivers said their car fell flat when hitting fifth gear.

Is this all the aero/down force bits on the car??? Or is this a tuning, supercharger heat issue? I don't know.


One poster here seems down on our "old" ZR-1's. Yes, we are not in a vacuum, but don't cut the ol' LT5 short!

When building the LT5, Chevrolet didn't reverse engineer every part to the cheapest price per widget before failure. They went with world class suppliers on a "we are going to show the world" basis that had the bean counters screaming.

I like the new Corvettes. I like old Corvettes. But, don't deny it... The old ZR-1's are a special breed. Our LT5's don't drop valves. Another friend is scared when his C6 Z06 warranty will go off. Is he going overboard? Maybe. But in the end, I am proud of my LT5!

[edram454]

???? what is he talking about?? decided to feel??? the lt5 did pass the 200 hour durability test and did set the record at nearly 176 mph for 24 hours. You dont have to feel it. It is what it is. How about the lt4?? Has it done anything or set any records?? I am perplexed to hear people trying to poke holes in the lt5 on this forum. This is one place I thought that most people would be in agreement but guess not. If its a joke I dont get it. whatever.

[Meanmyz]

In re-reading my earlier post now, I just wanted to add...in the shootout, the cars each got three runs. The cars mentioned all had very consistant runs. I am not sure how much difference it makes, but the 1990 ZR-1 mentioned had the "ballast" of a passenger. Not sure about the others.

Oh, I was there as a navigator for the road races. Maybe I will enter next year.

[XfireZ51]

Ed,

I started this thread as a means of discussing the pros and cons of the different engine architecture with their inherent advantages and disadvantages. I'd like to keep this on a technical level if possible. Many of us are fans of the C4 ZR-1 due to the unique power delivery we get from the LT-5. Many would like to see GM re-create that and believe that DOHC should be the future direction for Corvette in order for it to take its place among world-class automobiles. So far, GM doesn't seem to agree but they have also done a heck of a job refining the OHV architecture. My premise is that as good as the LT4 platform is, it's near topping out due to inherent limitations.
So your thoughts?

[mike100]

Ed,

... Many of us are fans of the C4 ZR-1 due to the unique power delivery we get from the LT-5. ...

I don't know when GM will break away from OHV V8's, but I feel it is somewhat on topic to point out the LT4's deficiencies as not a totally improved product while we all wish for something a little more exotic. My biggest point is the fact that there were a ton of you tube vids from week one that showed just about everything handing the new Z06's azz to it on roll races. Then came the GM apologists etc...

My take is that GM is holding back...way back... the engine only has a 1.75l supercharger that has to spin faster than the previous ZR1's LS9 unit which was 2.3l. I think it is blowing hot air and running with more internal parasitic drag. All the new cam phasing, direct injection, and all of that just to get the same power as the LS9??

Makes you wonder what the mid cycle refresh is going to bring.

[WVZR-1]

Makes you wonder what the mid cycle refresh is going to bring.

Every LT4 out there is doing the "dependability/reliability" R&D for the corporate folks. The future?

[XfireZ51]

Every LT4 out there is doing the "dependability/reliability" R&D for the corporate folks. The future?

Frankly, I learned my lesson when I bought a brand new 1984 C4 4+3 Z-51. Love the car,
BUT I won't do that again.

[Mr Blue]

I don't know when GM will break away from OHV V8's, My take is that GM is holding back...way back...
Makes you wonder what the mid cycle refresh is going to bring.
GM made a decision for the C5 to develop pushrod V8s and abandon the LT5. Much has been said whether or not that was the correct decision. People have pointed to the power levels of present day LSx engines and said it was the right decision. That can not be established from the data. They can rightly say that their program has been successful and they have achieved good gains in power. However the LT5 was, at the time of the decision, a viable 400+ HP engine.. It took GM 10 years of development to regain that level of power. Further increases came with increases in displacement and FI. All of us know that the existing LT5 was capable of much more. We would all like to have seen what development of the LT5 would have wrought. The supposed superiority of OHV engines in my mind is answered by the racing classes that do not penalize any valve configuration. In those classes OHC engines are dominant. The lone exception is unlimited drag racing. All that being said, we can and do enjoy the unique position that the ZR-1 hold in the Corvette lineage. It does not have to compete with a 25 year newer car. My hope is that GM corrects the LT1/LT4 problems soon. If they are holding back it's not working. Maybe they will adapt OHC heads to the latter block, but I doubt it.

[XfireZ51]

If you want an idea of where the LT-5 could have gone, just look at the Gen2 prototype Graham Behan discussed. 475hp without any displacement increase. And that was 25 years ago. Look at what Mercury Marine is doing with a VERY similar platform. They learned their lesson. If I was GM, I would be partnering w them on "productizing" the LS/LT block w the MM DOHC cylinder heads.The demise of the LT-5 was a combination of "penis envy" on the part of the Powertrain guys, and bean counter myopia from the green eye shade people.
Both of which I think we have seen too often from the RenCen and Warren.
I hope Mary Barra is changing that.

[Paul Workman]

i agree with Mike and Dom and others re their comments and observations relative to the advantages and power delivery of the DOHC vs. OHV. Faced with the superiority of the DOHC architecture, how much longer can GM continue to attempt to mitigate those advantages and embrace what is clearly become a 'damage control' effort (with the OHV architecture)?

Millions was spent on development of the new OHV LT1-4 motors. But, out of the box track performance (and reliability too) has been marginal. And, how much is GM going to bank on the C7's chassis improvements to save the bacon of their latest OHV entry? (Without even touching on the huge swell of reliability issues with LT4's heating PR catastrophe).

In spite of GM hoopla (and excuses), the acid test is going to be performance against European and Japanese in the theater of racing. In view of initial performance (or lack thereof, relative to the latest OHV entries) one has to wonder if we are seeing a repeat of GM's mentality when it stubbornly held to the L98 as being sufficient for Corvette buyers. Or, is there real hope to see an all-out focus on performance as the primary objective?

In the mean time, I've no fear of any match-up with any stock cammed stock-bottomed LS1, or 6.2L LS2, or 3 (LS7s?...maybe them as well, in the right venue?). Just crossing my fingers that GM will endeavor to build a motor and (GT) Corvette capable of the kind of 'take no prisoners' type of car the ZR-1 was when it hit the pavement!:cheers:

EDIT:

I concur w/ Dom's focus on the MM endeavor. However, that effort (last we saw it) was very preliminary; no variable cam/valve timing or direct injection - IIRC. So, that would also need to be considered.

For example, Ford and Mercedes has a pretty good examples of where DOHC might be had GM continued to develop it (C-link). (https://en.wikipedia.org/wiki/Mercedes-Benz_M156_engine)

[KILLSHOTS]

???? what is he talking about?? decided to feel??? the lt5 did pass the 200 hour durability test and did set the record at nearly 176 mph for 24 hours. You dont have to feel it. It is what it is. How about the lt4?? Has it done anything or set any records?? I am perplexed to hear people trying to poke holes in the lt5 on this forum. This is one place I thought that most people would be in agreement but guess not. If its a joke I dont get it. whatever.
Has it done anything or set any records??

The LT platform in the C7.R, which was co-developed with the 2015 Z06, won the Triple Crown of endurance races this year: Rolex 24 At Daytona, Mobil 1 Twelve Hours of Sebring and 24 Hours of Le Mans. According to Chevrolet, “the C7.R and the Z06 represent the closest link in modern times between Corvettes built for racing and the road, sharing unprecedented levels of engineering and components including chassis architecture, engine technologies and aerodynamic strategies.” So yes, the new LT platform has done something. But these facts are easy to escape: just FEEL that Chevrolet is lying about the close link between the production LT4 and the LT in the C7.R.

I have always loved and respected the LT5 as a nearly-bulletproof masterpiece, and I think there’s no question that the DOHC architecture is superior and will re-emerge when the small block has finally reached its limit, technologically. But I continue to assert that if the internet and the various Corvette forums that we frequent today existed back in 1990, we would have all heard instantly about the few LT5 failures that occurred and there would have been at least a few people FEELING that the LT5 is unreliable, despite its performance during the record run.

[spork2367]

i agree with Mike and Dom and others re their comments and observations relative to the advantages and power delivery of the DOHC vs. OHV. Faced with the superiority of the DOHC architecture, how much longer can GM continue to attempt to mitigate those advantages and embrace what is clearly become a 'damage control' effort (with the OHV architecture)?

Millions was spent on development of the new OHV LT1-4 motors. But, out of the box track performance (and reliability too) has been marginal. And, how much is GM going to bank on the C7's chassis improvements to save the bacon of their latest OHV entry? (Without even touching on the huge swell of reliability issues with LT4's heating PR catastrophe).

In spite of GM hoopla (and excuses), the acid test is going to be performance against European and Japanese in the theater of racing. In view of initial performance (or lack thereof, relative to the latest OHV entries) one has to wonder if we are seeing a repeat of GM's mentality when it stubbornly held to the L98 as being sufficient for Corvette buyers. Or, is there real hope to see an all-out focus on performance as the primary objective?

In the mean time, I've no fear of any match-up with any stock cammed stock-bottomed LS1, or 6.2L LS2, or 3 (LS7s?...maybe them as well, in the right venue?). Just crossing my fingers that GM will endeavor to build a motor and (GT) Corvette capable of the kind of 'take no prisoners' type of car the ZR-1 was when it hit the pavement!:cheers:

EDIT:

I concur w/ Dom's focus on the MM endeavor. However, that effort (last we saw it) was very preliminary; no variable cam/valve timing or direct injection - IIRC. So, that would also need to be considered.

For example, Ford and Mercedes has a pretty good examples of where DOHC might be had GM continued to develop it (C-link). (https://en.wikipedia.org/wiki/Mercedes-Benz_M156_engine)

First off, these are all OHV engines....

But comparing pushrod V8's to OHC V8's (whether single or dual cam) isn't a clear cut "this is better and here's why" comparison.

The configuration is largely irrelevant as long as Chevy and Dodge are still putting out pushrod OHV engines that are every bit the equal, if not slightly superior to Ford's modular OHC engines. Let's face it, if someone can build a pushrod engine for a top fuel dragster that makes 10,000 HP, the cam configuration and pushrods aren't the limiting factor. And with variable valve timing we can now compensate for a lot of factors and make a single cam do what it never could in the past.

Direct injection and variable valve timing are far more relevant than cam architecture at this point in time. After that the market is banking on forced induction V6's.

[Paul Workman]

First off, these are all OHV engines....

But comparing pushrod V8's to OHC V8's (whether single or dual cam) isn't a clear cut "this is better and here's why" comparison.

Really? Can you provide data of examples where a NA OHV motor of comparably equal technology and displacement demonstrates equal peak power and superior power under the curve while maintaining a smooth idle? (I referenced the Mercedes M156 6.2L NA as an example of like displacement with like technologies - i.e., cam phasing, etc., and there are others. Example? For example: can you support your claim of comparable OHV being superior to a 25 year old LT5 across the rpm spectrum with a smooth idle?) Point/Counterpoint.

The configuration is largely irrelevant as long as Chevy and Dodge are still putting out pushrod OHV engines that are every bit the equal, if not slightly superior to Ford's modular OHC engines.

*..."engines that are every bit the equal..."*

Showing us the data to support that claim (w/ comparable displacement) would help to provide some validity to that statement...

Let's face it, if someone can build a pushrod engine for a top fuel dragster that makes 10,000 HP, the cam configuration and pushrods aren't the limiting factor.

How do those very special application BLOWN motors (rebuilt every 1/4 mile run) have any relevance to the architecture discussion at hand??:confused:

And with variable valve timing we can now compensate for a lot of factors and make a single cam do what it never could in the past.

Granted, VVT is a modern asset to OHV. However, it is even more of an asset to DOHC architecture as the exhaust valve timing can be independent from intake cam lobe timing. Point/Counterpoint.

Direct injection and variable valve timing are far more relevant than cam architecture at this point in time. After that the market is banking on forced induction V6's.

Well, I refer (again) to the example of the DOHC Mercedes NA M156 which shares those same technological advances AND displacement with GM's current OHV NA LT1. I dunno, but most of legit true apples to apples comparisons of DOHC vs. OHV, proving superiority of the latter is pretty thin in the evidence side of the argument.

Far as blown V6's goes, one only has to see one of the 1/2 mile or 1 mile shootouts to see the truth of "If you ain't blowin, you ain't goin!" But, those kick-*** Nissan V6s are also DOHC, by the way... But, as Mike already said, hybrids w/ electric FWD may be what really makes DOHC moot - to your Point/Counterpoint.


:cheers:

[32valvesftw]

One of the pros to the DOHC, is that one can use a more aggressive cam grind and still maintain a good idle.
One of the Cons of the DOHC is that the engine even though it is very well designed is not as simple to work on as a pushrod small block. Assuming you don't have 17 miles of hose and tube on your pushrod V8. What I am referring to for one thing is valve guide seals, with a SBC you can fairly easily change them with the engine in the car.
They say push rod engines make better torque, however I do not understand the physics involved with that assumption. I think it goes back to the cam grind utilized in the DOHC engines and stroke of the engine.

[XfireZ51]

Can someone name a modern day GM Powertrain motor which is NOT a V8 and NOT OHC?

[edram454]

the ls engines will keep making power by increasing power adders, turbo, twin turbo, twin superchargers and ramping up boost until the actual materials wont hold. From what I have seen as soon as they starting ramping up power they start adding better internals so it will stay together. At some point I would hope they would entertain the dohc technology and try to get more power that way and not rely so much on just adding boost. Every auto maker is guilty of adding boost to achieve there horsepower goal.

They might consider the camless engine. Using the computer to electronically open and close the valves. This has been something Lotus was trying to develop but at the time there wasnt a device that would open and close the valves fast enough. This was something Dave McLellan spoke about in his book. Camless?? 1 cam, 4 cam and no cam.

ed ramos #3028

[Paul Workman]

The "Waxer vs. Warrior" question.

I was shocked to learn that as many as 1/3 of ZR-1 drivers have never bumped the rev limiter. And, some admit to never exceeding 5500 (!!) rpm! That being the case, unless balancing a nickel on its edge while sitting on the plenum of an idling motor is what excites them, things like which architecture affords what advantage...is pretty moot. :rolleyes: Might as well drive a "Dunwoody Cruiser"! (Our Atlanta friends know what I mean!:p But, translating for those not from around there, think of the movie National Lampoon's "Family Vacation" and the Family Truckster. That car...driven by soccer moms in tennis outfits)

http://www.autoblog.com/photos/family-truckster/

[spork2367]

One of the pros to the DOHC, is that one can use a more aggressive cam grind and still maintain a good idle.

I'm curious as to what you basis for this comment is?

Really? Can you provide data of examples where a NA OHV motor of comparably equal technology and displacement demonstrates equal peak power and superior power under the curve while maintaining a smooth idle? (I referenced the Mercedes M156 6.2L NA as an example of like displacement with like technologies - i.e., cam phasing, etc., and there are others. Example? For example: can you support your claim of comparable OHV being superior to a 25 year old LT5 across the rpm spectrum with a smooth idle?) Point/Counterpoint.

You're trying to make too many comparisons with too many variables. You throw out the Mercedes M156, a small production engine and compare it to an assembly line chevy motor that they make probably 10 times as many of. No, there isn't a fair comparison out there. The LT5 was a small production, hand built engine with tight tolerances and materials that weren't cost effective to bring to base corvette.

*..."engines that are every bit the equal..."*

Showing us the data to support that claim (w/ comparable displacement) would help to provide some validity to that statement...

Closest comparison I could come up with is Ford DOHC 5.4 (lincoln navigator version) vs Chevy 5.3 (truck version). Both have a flat torque curve that makes peak torque that starts at about 2800 RPM. However, the Ford drops off at 4800 RPM while the Chevy holds max torque until 5600 RPM. Both obviously have smooth factory idles. Do I think this is a completely fair comparison? No. There is no data that allows me to say they were shooting for the same goals when they built the engine and that was the best they could do.

How do those very special application BLOWN motors (rebuilt every 1/4 mile run) have any relevance to the architecture discussion at hand??:confused:

It seemed like you were implying that the architecture was a limiting factor in some way. If that wasn't what you were saying, ignore that.

Granted, VVT is a modern asset to OHV. However, it is even more of an asset to DOHC architecture as the exhaust valve timing can be independent from intake cam lobe timing. Point/Counterpoint.

Could be done with purpose built hydraulic lifters. It just isn't at this point because it isn't cost effective.

Well, I refer (again) to the example of the DOHC Mercedes NA M156 which shares those same technological advances AND displacement with GM's current OHV NA LT1. I dunno, but most of legit true apples to apples comparisons of DOHC vs. OHV, proving superiority of the latter is pretty thin in the evidence side of the argument.

I'm not claiming one is ultimately superior to the other. They both have their advantages. People in here want to use the reliability of the LT5 as a a defense for DOHCs, but that is nonsensical. The LT5 was reliable because it was hand built to close tolerances using materials that were designed for ultimate reliability. That fact remains that a DOHC engine has far more parts than a pushrod engine. That inherently makes them more prone to failure. If I went out and built an LS1 with aluminum block, aluminum liners, nikasil plated them and the aluminum pistons..etc. You'd have a motor that was more reliable than even an LT5. Why doesn't Chevy build that? Not enough people are going to pay $15,000 more for a corvette because the engine lasts for 250,000 miles instead of 150,000.

Far as blown V6's goes, one only has to see one of the 1/2 mile or 1 mile shootouts to see the truth of "If you ain't blowin, you ain't goin!" But, those kick-*** Nissan V6s are also DOHC, by the way... But, as Mike already said, hybrids w/ electric FWD may be what really makes DOHC moot - to your Point/Counterpoint.


:cheers:


ROI

For the couple hundred or couple thousand people who want a flatter torque curve, with a dead smooth idle and 8000 RPM top end, Chevy isn't going to spend 500,000,000 dollars to retool a plant to build a DOHC V8. And they would piss off more Chevy diehards than they would win over.

You could put the average corvette driver behind the wheel of a 1996 Grand Sport and a 1995 ZR1 and they wouldn't be able to tell you how they felt different. They are selling to the people who are one standard deviation from the center of the bell curve. ZR1 owners are two standard deviations out and Chevy will likely never build an engine that we think would be comparable to the LT5.

[Meanmyz]

You could put the average corvette driver behind the wheel of a 1996 Grand Sport and a 1995 ZR1 and they wouldn't be able to tell you how they felt different.


I am lucky enough to own both a 1996 Grand Sport and a 1995 ZR-1. I sure can tell you the difference between the two... One has a good engine. The other one does a pretty good impersonation of sex (what is that?), but with your cloths on!

[mike100]

...Chevy will likely never build an engine that we think would be comparable to the LT5.

They will be forced to someday by emissions laws. It helps to have two cams per head that can phase exhaust and intake separately to control overlap and therefor cylinder pressure. There has been some though of the camshaft going extinct if some kind of electrically actuated valve technology ever becomes reliable. This will make the argument on how many valves per cylinder rather than cams, but I would venture that the lighter the valve, the better.

Some of this tech will probably preclude engines from going much over 6000 rpm, but if you are torque blending with an electric assist, stored mechanical energy (like KERS), turbos, and all of this, why would you need high rpm? VW used to make a supercharged and turbocharged engine in a very small displacement, but stopped due to costs I think. The days of big inch lumbering NA engines are not long. Maybe in trucks for a bit longer...

[spork2367]

I am lucky enough to own both a 1996 Grand Sport and a 1995 ZR-1. I sure can tell you the difference between the two... One has a good engine. The other one does a pretty good impersonation of sex (what is that?), but with your cloths on!

But you aren't the average corvette driver, as is evidenced by the fact that you are here on this forum being part of this discussion. :)

[Meanmyz]

But you aren't the average corvette driver, as is evidenced by the fact that you are here on this forum being part of this discussion. :)

Very true! :cheers:

[XfireZ51]

I'm curious as to what you basis for this comment is?




ROI

For the couple hundred or couple thousand people who want a flatter torque curve, with a dead smooth idle and 8000 RPM top end, Chevy isn't going to spend 500,000,000 dollars to retool a plant to build a DOHC V8. And they would piss off more Chevy diehards than they would win over.

You could put the average corvette driver behind the wheel of a 1996 Grand Sport and a 1995 ZR1 and they wouldn't be able to tell you how they felt different. They are selling to the people who are one standard deviation from the center of the bell curve. ZR1 owners are two standard deviations out and Chevy will likely never build an engine that we think would be comparable to the LT5.

I know that GM tried to put out the message that the LT-4 was "very close" to the LT-5 for performance. I don't buy it for a second. The 4s may have been a strong SBC and EVEN IF they had similar #s, where those peaks took place is vastly different. That's where the rubber meets the road. Its why we wave bye bye to the LT-4 after the first 1/8th mile. As Paul keeps saying, its not the peak number but the area under the curve, and the LT-5 covers a lot more of the real estate on a dyno chart.

[spork2367]

They will be forced to someday by emissions laws. It helps to have two cams per head that can phase exhaust and intake separately to control overlap and therefor cylinder pressure.

Yeah, but it will be in a V6 with a turbo. They aren't likely to pay to costs to design an all new V8 when it won't meet emissions in another 8 years.

I know that GM tried to put out the message that the LT-4 was "very close" to the LT-5 for performance. I don't buy it for a second. The 4s may have been a strong SBC and EVEN IF they had similar #s, where those peaks took place is vastly different. That's where the rubber meets the road. Its why we wave bye bye to the LT-4 after the first 1/8th mile. As Paul keeps saying, its not the peak number but the area under the curve, and the LT-5 covers a lot more of the real estate on a dyno chart.

And for the average corvette driver, it was. I understand the advantage of the LT5 vs the pushrod engines of the same era, but most corvette customers didn't want to pay for it then, and wouldn't want to pay the premium today if the same technological advances of today were put in a new engine. It's the same reason Porsche built air cooled SOHC flat 6 engines into the late 90's.

That being said, there is not a car with a DOHC engine today in the same price range as the corvette that can trump it. Keep in mind, the LT5 wasn't really the king of the hill in its day. There were faster production cars. F40s and 959s were both faster in acceleration and top speed.

There is a reason there are more mustangs than corvettes, and more corvettes than ferraris. Price. And there is no return on investment for Chevy to retool a plant to build an advanced DOHC engine and bump the price of a corvette up 25% or more.

If there were enough valid counterpoints supporting a DOHC V8, they'd be making one today.

[Meanmyz]

The days of big inch lumbering NA engines are not long.

That is sad and probably true. And, you wonder why it should have to be like that. Today's engine's are the cleanest and most efficient they have ever been.

I am with letting the technology take us there through free enterprise and competition...NOT being forced there by a socialistic overreaching big government. ...eh, I have too much to do to get started on this topic, so I won't.

[spork2367]

The days of big inch lumbering NA engines are not long. Maybe in trucks for a bit longer...

Most torque under the curve for the future...:(

[5ABI VT]

Most torque under the curve for the future...:(

Makes as much of soundtrack as me riding my bike.. Just not cool lol.


Big lumbering engines are imo the direct result of a pushrod architectures limitations. Specifically the single cam. You just can't make an engine with a single cam have a smooth idle.. Torque down low for fuel economy (classic pickup truck formula) and make a high hp number up top that makes an excellent hp/L statistic.

Case in point the Ls7. Huge potential ? Yes because it's 7L. Oem cams have a wide lsa because that one cam has to try and do it all. Want to chase 650-700hp? We're talking a pretty big cam with a choppy idle that sounds like a farm tractor missing a spark plug. Compared to say the F12s v12. Oem form.. 730hp from 6.2L. 505 from 7L. That's a 225 hp difference. The Ferrari v12 is Complex, expensive and spins to the moon which isn't a formula that works for pickup trucks so it's not a path gm chose to follow.

[spork2367]

Makes as much of soundtrack as me riding my bike.. Just not cool lol.


Big lumbering engines are imo the direct result of a pushrod architectures limitations. Specifically the single cam. You just can't make an engine with a single cam have a smooth idle.. Torque down low for fuel economy (classic pickup truck formula) and make a high hp number up top that makes an excellent hp/L statistic.

Case in point the Ls7. Huge potential ? Yes because it's 7L. Oem cams have a wide lsa because that one cam has to try and do it all. Want to chase 650-700hp? We're talking a pretty big cam with a choppy idle that sounds like a farm tractor missing a spark plug. Compared to say the F12s v12. Oem form.. 730hp from 6.2L. 505 from 7L. That's a 225 hp difference. The Ferrari v12 is Complex, expensive and spins to the moon which isn't a formula that works for pickup trucks so it's not a path gm chose to follow.

And the v12 torque curve sucks.

[5ABI VT]

And the v12 torque curve sucks.

Definitely subjective .. But to me I don't care for down low torque. It's not needed. Gearing can give you torque , but can't give you hp. With the right gearing that 510lvs -ft can easily equal a higher torque motor at the tire. For me that torque curve is beautiful !! All that torque up high .. Where the motor will remain under wot through the gears is all that matters to me. If I was towing a trailer.. Sure give me an ls7. If I had a 4000lb pickup .. Sure give me an ls7. For my kind of sports car.. Give me that v12 any day of my life.

My Lt4 I built is a 370ci solid roller.. Makes peak torque at 6400 and peak power at 7400. Idle ? Well I hate choppy idles.. But I'm going to be on the receiving end of that idle lol. What this motor will give me is smiles from 6-8500rpm !! :-D
Would I have rather built an LT5? I think the answer Is obvious !

[spork2367]

Definitely subjective .. But to me I don't care for down low torque. It's not needed. Gearing can give you torque , but can't give you hp. With the right gearing that 510lvs -ft can easily equal a higher torque motor at the tire. For me that torque curve is beautiful !! All that torque up high .. Where the motor will remain under wot through the gears is all that matters to me. If I was towing a trailer.. Sure give me an ls7. If I had a 4000lb pickup .. Sure give me an ls7. For my kind of sports car.. Give me that v12 any day of my life.

My Lt4 I built is a 370ci solid roller.. Makes peak torque at 6400 and peak power at 7400. Idle ? Well I hate choppy idles.. But I'm going to be on the receiving end of that idle lol. What this motor will give me is smiles from 6-8500rpm !! :-D
Would I have rather built an LT5? I think the answer Is obvious !

Sure, but that pretty much craps all over the argument for why DOHCs are the greatest thing ever for the V8.

[5ABI VT]

One funny example I like to use is the L98 c4. Those guys will tell you for days that it's a 'torque monster' and then you should see their faces when they get pulled by a Honda S2000 with enough torque my lawn mower wouldn't even be jealous. Torque from a big cube pushrod motor to me is a recipe for good low speed torque via displacement , excellent fuel economy and greater service life due to low Rpms.
All of which is a formula for gms bread and butter .. Pickup trucks.

[spork2367]

That fancy 320k F12 takes 3.6 seconds to make it to 60...:sleepy1:

:)

[Fully Vetted]

...The days of big inch lumbering NA engines are not long. Maybe in trucks for a bit longer...

Which is why I think the 2013 60th Ann. 427 car will be highly collectable. Most likely the last BB Corvette ever produced.

...That being said, there is not a car with a DOHC engine today in the same price range as the corvette that can trump it. Keep in mind, the LT5 wasn't really the king of the hill in its day. There were faster production cars. F40s and 959s were both faster in acceleration and top speed...

And I wouldn't trust either one of them to get me to the grocery store and back let alone go on a road trip. But I guess that's beside the point...

[32valvesftw]

[QUOTE=spork2367;230703]I'm curious as to what you basis for this comment is?

the OHC arrangement allows for a faster acting valve train, and I think it allows for less overlap. It is overlap that gives the radical cam its lump. Here is a pretty good reference
https://books.google.com/books?id=Dy-Qvb_X7Q0C&pg=PA113&lpg=PA113&dq=OHC+Cam+profiles&source=bl&ots=Oy126Ugpzm&sig=LGVKsXfWEkBWa_niir5C3c7Q1ac&hl=en&sa=X&ved=0CF4Q6AEwDGoVChMIm4aO2JmpxwIVBk6SCh0FywAZ#v=on epage&q=OHC%20Cam%20profiles&f=false

[XfireZ51]

The reasons for the tight LSA IS FOR "up top" breathing. But the downside of a tighter LSA AND MORE OVERLAP is a lumpy idle. The 4valve eschews all of that because the 4 smaller valves have more area than the two big ones, therefore there is less lift and duration required. If you look at the LS motors, they had LSAs in the 112-114* range to give a smooth idle and for emissions. BUT they had very high lift. At slow engine speeds that works, but higher revs required lots of energy to move the more massive valves. The 4 valve has less inertia, lighter valve train which is why the valve seat pressure is so much less in an OHC configuration. It also eliminates the pushrod flex present due to transmitting motion in nearly a 180* direction. As Mike pointed out, the twin cam also allows for higher variability in cam phasing whereas the in block cam has a cam phasing that is cast into it(unless you're using a more complex cam ala the Dodge Viper). So the single cam tends to be more of a compromise, although for trucks it's great. The reason OHC make power up top is because they can. The LT-5 was at ~ 5500rpm for over 24hours in the record run. The valve train for the most part was languishing. An OHV config would be much closer to its breaking point at that level. An F1 is turning 15-20k for an hour. Funny cars and dragsters blow up in a matter of seconds.

[Bearly Flying]

Compared to say the F12s v12. Oem form.. 730hp from 6.2L. 505 from 7L. That's a 225 hp difference. The Ferrari v12 is Complex, expensive and spins to the moon....



How many Ferrari's do you see with 100,000 miles on them?

How many Ferrari's have set an International Speed Record?

How many Ferrari's change their own oil or work on their engines?

How many Ferrari's are even around from the early 90's?

Nuff said.

[5ABI VT]

It was more of a comparison of dohc vs the ls7 which is pushrod. I believe Ferrari had a failed attempt at the zr1s records ? I believe it was the 550 maranello or maybe the 575 I can't recall. They had tire issues and had to cancel.

Anyhow my thoughts on dohc are this.. Imagine gm chose to continue the LT5 to this day. It sure as hell would have made more than 505hp. I'd have to guess with no bore spacing limitations, dry sump , huge heads, direct injection and 7.0L.. I'd have to say 600-650 hp would have been easily possible in oem pussycat form ? Maybe the c7zo6 wouldn't be suffering thermal issues with a dohc NA motor instead of a pushrod with a blower on top.

[Kevin]

friend of mine puts ~10,000 a year on his RedHead. It's a fairly reliable car for him. The reason most ferrari owners don't do their own work is that other ferrari owners want to see records of maintenance from Ferrari dealerships. They don't want to see that Joe's house of tires and waffles fixed a flat or remounted a wheel. It's stupid but when you're dealing with a xx,xxx engine repair bill I can see why they're like that. Of course we're not that far off if you have to send your car out for work.

[pantera1683]

Which is why I think the 2013 60th Ann. 427 car will be highly collectable. Most likely the last BB Corvette ever produced.

Big Block?

[edram454]

Big Block?

Im surprised nobody caught it sooner. BB?

ed ramos #3028

[Kevin]

Im surprised nobody caught it sooner. BB?

ed ramos #3028

thought that was standard short hand.

[XfireZ51]

thought that was standard short hand.

Although it's a 427, that doesn't make it a big block. It's still an LSx block just a bigger bore. I may be oversimplifying it.

[Kevin]

Although it's a 427, that doesn't make it a big block. It's still an LSx block just a bigger bore. I may be oversimplifying it.

fair point, well made and nicely presented. I'd forgotten that the ls7 was a sbc

[Fully Vetted]

fair point, well made and nicely presented. I'd forgotten that the ls7 was a sbc

My mistake. I thought it was a BB.

[mike100]

The LSx all have the same block dimension, but I took at as any v8 over 400 cubic inches to be a "big block" as the historical packaging generally had its threshold at about that size.

[Fully Vetted]

I had a 70 1/2 TA that had a 400 small block (Ram Air III). If I'm not mistaken the "small block/big block" designation was only applied to Chevy engines, tho. But the Pontiac 400 was always referred to as a small block.

[XfireZ51]

The LSx all have the same block dimension, but I took at as any v8 over 400 cubic inches to be a "big block" as the historical packaging generally had its threshold at about that size.

396 was a big block back in the day, so displacement was not the determination for the designation. BB cylinder heads would not work on a small block and vice versa.

[Kevin]

I thought it had to do with the bore spacing?

[XfireZ51]

I thought it had to do with the bore spacing?

Well you could say bore spacing has something to do with it. Here's a very illustrative video of the difference. The name "big block" becomes pretty obvious.

http://youtu.be/LPZuEWli4gQ

[Fully Vetted]

Wasn't there both a 396 BB and a 396 SB as well?

[Mystic ZR-1]

402 Big Block
400 Small Block (not to be confused with the Pontiac 400)

[mike100]

396 was a big block back in the day, so displacement was not the determination for the designation. BB cylinder heads would not work on a small block and vice versa.

Well they actually had a 366 big block chevy for delivery trucks but i think it was designed w a small piston so as to have a thick cylinder bore as they expected extended periods of full throttle operation.

But in my opinion 396 is the same as 400 cubic inches especially since i qualified my statement with the word 'about' haha... The 402 BB was a 396 with a taller deck height for trucks as i seem to recall.

The conversation wouldnt be complete if we didnt talk about the BBC canted valve angles and better rocker ratios, but like the LT5, weight and packaging were a big part of its demise.

[mike100]

Isnt engine size and handgun caliber sayings similar? Your choice should start with a '4'.

[spork2367]

I love all the turns this discussion has taken. We have like 5 sub discussions going...lol.

Compared to say the F12s v12. Oem form.. 730hp from 6.2L. 505 from 7L. That's a 225 hp difference. The Ferrari v12 is Complex, expensive and spins to the moon....

Not sure if this is a criticism or defense of the chevy. The chevy motor can be driven like a pickup truck. That Ferrari isn't going to like chugging around at 1500 RPMs. So the DOHC nature of the F12 doesn't magically give it a decent bottom end. Driving on public roads, you're not going to spend a ton of time at 8000 RPMs.

If you look at the engine builders challenges and some of the protouring builds out there, there are plenty of nice idling street friendly 700+ HP pushrod engines.

How many Ferrari's do you see with 100,000 miles on them?

I don't go around looking at Ferrari odometers on a regular basis, but just due to the shear number produced versus the ZR1, I'm sure there are more out there than ZR1s in the same time span by a fair number. Look how many sub 50k mileage ZR1s are out there. I bet even if you looked at the percentages the Ferraris probably are higher mileage.

How many Ferrari's have set an International Speed Record?

Lots. They've set many more records than the ZR1. Just not the particular record you're talking about.

How many Ferrari's change their own oil or work on their engines?

Completely irrelevant to any of the numerous conversations at hand, but I doubt most of the people who plunked down the asking price for the ZR1s when they came out were doing their own wrenching either.

How many Ferrari's are even around from the early 90's?

As far as a percentage of those produced; probably more than ZR1s from the same period. Ferraris were just less likely to be parted out and more likely to be repaired, or stored in someone's shed. They don't usually end up in salvage yards.

Nuff said.

[XfireZ51]

I love the all the turns this discussion has taken. We have like 5 sub discussions going...lol.

It was meant to be a bit of a catchcan :-D for the way other threads "evolve" or "devolve" depending on your point of view.

[Billy Mild]

Which is why I think the 2013 60th Ann. 427 car will be highly collectable. Most likely the last BB Corvette ever produced.



And I wouldn't trust either one of them to get me to the grocery store and back let alone go on a road trip. But I guess that's beside the point...

I would trust that 959 in a heartbeat. Porsche's are the only true exotic that can be driven daily. 959 was the pinnacle of engineering back in that era. It was only surpassed by the 996 Turbo in performance, and even then the 996 was not as technologically advanced.

Although it's a 427, that doesn't make it a big block. It's still an LSx block just a bigger bore. I may be oversimplifying it.

True big blocks are designed differently. They have a lot of cylinder material. The LS7 engine has almost paper thin cylinder walls. There is no service life in that engine.

[FU]

True big blocks are designed differently. They have a lot of cylinder material. The LS7 engine has almost paper thin cylinder walls. There is no service life in that engine.

Chevrolet big blocks are an engine family made production from 1958-1972 I believe. Ranging from 348-454 ci then a later year over the counter up to 572 inches.

The LS7's (part of the small block engine family Gen. III & IV) are modern day monsters that are clean from a emissions view and get decent fuel mileage . The cylinder walls are very easily replaced. The service life of an LS engine is an extremely long one.

:cheers:

[spork2367]

I would trust that 959 in a heartbeat. Porsche's are the only true exotic that can be driven daily. 959 was the pinnacle of engineering back in that era. It was only surpassed by the 996 Turbo in performance, and even then the 996 was not as technologically advanced.

Don't break his heart and tell him that the 959 was using nikasil plated alloy liners, sodium filled exhaust valves, and a dry sump years before any Corvette...

Chevrolet big blocks are an engine family made production from 1958-1972 I believe. Ranging from 348-454 then a later year over the counter up to 572 inches.

The LS7's (from the LS engine family) are modern day monsters that are clean from a emissions view and get decent fuel mileage . The cylinder walls are very easily replaced. The service life of an LS engine is a extremely long one.



Big blocks were produced way later than 1972. I had a 2000 Chevy 3500 pickup with a 7.4. My dad still owns his 1997 Chevy Express 3500 van with a 7.4.

[FU]

Chevrolet BB's were produced until 2007 as Vortec L18 truck engines.

Mark IV which were the performance engines stopped production in Tonnawanda NY in 72.

[rkreigh]

read from Dave M.'s book, corvette from the inside

pushrods

packaging, costs, weight, low hood line, ease of maint

HIGHER PROFIT MARGINS!!!


DOHC

flow velocity, superior light weight valves, expensive, hand built, heavy, barely fits, broad wide and tall (no low hood line)


the low intake of the LS and light weight makes the modern vettes more affordable.

the DOHC ford has gotten pretty good at HP and light weight AND being affordable which to me just means GM needs to get with the program

corvette needs a real engine again.

the LT5 is a real engine. given 20+ years of development there is no question the LT5 would be able to match the 520+ hp of the new Voodoo flat crank ford.

from an engineering standpoint there is no question the DOHC has some notable advantages, but not from a cost or packaging.

and with modern airflow computational analysis, the new heads flow 370 CFM which is better than BB chevy RACE heads of yore.

I like the little caddy twin turbo v6, it's sneaking up on 500 hp

slap two ecotec heads together with DI and hang a pair of turbos on it and GM could easily build a modern NA engine with over 600 HP that would rev to the moon and have the durability we crave.

I've blown up about 6 pushrod motors racing, I've yet to hurt an LT5 (just saying).

GM needs to smell the coffee the future is turbos, electic drivetrains (supplemental motors aka La Ferrari, NSX, Pooch, ect....)

but be prepared to pay for it. the vette is still a working mans exotic and that's how GM has positioned the car and it's trying to be "all things to all people" to sell more cars

why else would you see a covertable automatic z06 (those words don't even seem to go together do they?)

simple, sell cars. GM at the end of a day is a business, and the vette is finally turning the corner and looks like it may survive for a while longer

give me a turbine spinning a generator, and 4 electric motors with torq vectoring I don't need no STEENKEN valves or pistons :-D (aka Jag CX75)

I hope to see this before I go, it's on my bucket list.

[spork2367]

the DOHC ford has gotten pretty good at HP and light weight AND being affordable which to me just means GM needs to get with the program

Except Ford is banking their future performance on the 3.5 liter ecoboost V6. It's in their new GT concept and in the Raptor. Removing the V8 from the Raptor, a pickup truck, is the writing on the wall. So GM really missed the boat on a DOHC V8. But it didn't really matter because the LS was a cheaper more reliable motor that was cheaper and easier to get power out of than any of the DOHC Ford engines.

The Corvette won't ever see a DOHC engine in production. It simply would cost too much. They want supercar performance on a budget. Ferrari and Lamborghini can continue to build V10 and V12 monsters because those buyers aren't concerned with gas mileage or cost.

[KILLSHOTS]

Wanting an expensive, DOHC V8 to appear under the hood of a Corvette again any time soon is like wanting a brain to appear in the head of Scarlett Johansson.

The LT5 was an amazing piece of engineering, but unless market research proves beyond any doubt to GM that folks will hurriedly line up to plunk down deposit checks on a $150K Corvette, it was most likely a once in a lifetime event. In fact, not even "Corvette guys" really care about this issue; it's only the few of us who care about the ZR-1's existence who would ever even have this discussion. Unfortunate, but true. Stingray owners could not care less that it only takes a single camshaft to rocket them to 60mph in under 4 seconds.

[WVZR-1]

GM had all of the DOHC R&D done many years ago with many millions of miles with cars that generally were better maintained than the average product GM put on the highway. Had the NORTHSTAR done better there would be likely many or at least a few more DOHC projects that met the highway.

NORTHSTAR cars either did extremely well for years or with lack of maintenance most failed. They tried very hard to make that project work. VERY!

It's last install in the Bonneville was pretty well accepted and most that I know that owned them would have bought another. I found it just to difficult to move past the S/CHGD 3800's - I've had several and most with over 200K some slightly less with only one failure. Still drive a S/CHGD SSEi '03 last year.

[mike100]

Didn't NorthStar engines lose headgaskets pretty regularly? That was all about the same time that Dexcool problems started cropping up.

They advertised 5 years 100k miles on the tuneup/coolant service and guess what, people didn't even do the maintenance at all, much less at 60-80k that would have been more reasonable. Even with accounts of perfectly good running high mileage GM cars out there, I would never buy one (except for Corvette because there is no other car competing in that price range). I got burned on a couple of 90's trucks (one small block based one and the gmt-800 LS based one- complete lemons... they have cut too much out of the cars they make and they just don't seem to run long enough before failing. Even my 2008 C6 needed a water pump at 22k miles.

[WVZR-1]

The Shelby Series 1 were a tweaked Northstar I believe and there were a couple of different Notrthstar products. They ain't all the same and most aren't the product that's most frequently thought of. The Shelby might have been done on the '99 and earlier product. FWD & RWD product I believe.

4.6 320 HP VVT in the XLR? '04 or so.

GOOGLE might be your friend here OR user ID "Aurora40" - I've not seen Bob around for a long while but Bob was certainly a Northstar fan. Most should remember Bob.

[edram454]

why are there discussions praising ferraris and porsches in this forum. As a Corvette enthusiast, I hate Ferrari's and Porsches to death. I would never own or desire one. I would buy one just to resell it and make some money. Ferraris are buzz bombs and make their power in extremely high rpms and little displacement and now with multiple turbos, the porsches have that flat six with many pounds of boost.. they are refined but frankly bore me to death... dont like the sounds they make and the ridiculous price tags are staggering... some people just crap out money because they can... If I didnt have a Corvette I would not have another sports car period. That is just the way I roll...

ed ramos #3028

[XfireZ51]

Ed,

You may not like them but you can certainly respect them and the engineering that goes w that.

[spork2367]

Ed,

You may not like them but you can certainly respect them and the engineering that goes w that.

This. A true automotive guy can appreciate all these things. I would own a Porsche or Ferrari in a heartbeat. They are amazing marvels of automotive engineering. How many Chevy engines have revved to 19,000 RPMs like the Ferrari V12 F1 engines? Hell, if it weren't for Porsche, the LT5 would never have had its nikasil plated liners and pistons.

[edram454]

I do respect them because of the engineering those companies invested in them but it is just hard to accept this country being second fiddle to any other country in the world in anything. I would never buy one except to flip for a profit like I stated earlier. I consider myself a true automotive guy but for me to own a pleasure craft I must like it first and that is the reason I would never own one. I will always feel the Corvette is the best and only sports car to own. I never root for any other car in racing except American cars in any type of racing. So there!!

ed ramos #3028

[spork2367]

I do respect them because of the engineering those companies invested in them but it is just hard to accept this country being second fiddle to any other country in the world in anything. I would never buy one except to flip for a profit like I stated earlier. I consider myself a true automotive guy but for me to own a pleasure craft I must like it first and that is the reason I would never own one. I will always feel the Corvette is the best and only sports car to own. I never root for any other car in racing except American cars in any type of racing. So there!!

ed ramos #3028

Your view seems to be a bit bigoted. I mean, what's your view of Zora Duntov? Belgian born, German trained, with strong racing experience from England...

If it weren't for European two seat sports cars, the Corvette wouldn't even exist. The majority of the technology used in Corvettes was used by foreign car manufacturers first. Hell, the LT5 was designed by Lotus in England.

Having brand loyalty is one thing. And the Corvette is a very American vehicle, from it's current pushrod V8 to its consumer friendly price.

But it wasn't created exclusively by Americans, with exclusively American technology, and isn't the greatest car ever manufactured.

Sorry if you're offended by that, but your view is awkwardly narrow minded.

[KILLSHOTS]

Your view seems to be a bit bigoted. I mean, what's your view of Zora Duntov? Belgian born, German trained, with strong racing experience from England...

If it weren't for European two seat sports cars, the Corvette wouldn't even exist. The majority of the technology used in Corvettes was used by foreign car manufacturers first. Hell, the LT5 was designed by Lotus in England.

Having brand loyalty is one thing. And the Corvette is a very American vehicle, from it's current pushrod V8 to its consumer friendly price.

But it wasn't created exclusively by Americans, with exclusively American technology, and isn't the greatest car ever manufactured.

Sorry if you're offended by that, but your view is awkwardly narrow minded.
And it’s not just Ferraris and Porsches. He also doesn’t like the “lousy LT4 car” (see post #11 ). And he’s certainly not impressed by the LS2 or LS3 and doesn’t FEEL that the LS7 is bulletproof (see post #6). I guess the only engine worth buying that any manufacturer ever produced was the LT5.

[edram454]

Listen spork2367, I am offended by your bigot comment. This is a corvette forum and those are my personal views and preferences of the Corvette. I know more about Zora Duntov than you will ever know since I studied his life and career and made it a point to meet him and Elfi on a few occasions. What does my view of zora or anybody else have to do with my sports car preference?? I dont appreciate your comments. You sound like you should be in some European car forum not on a Corvette forum. Does the fact that I don't like foreign cars make me bigoted? I appreciate the engineering invested in some of those cars but like I said, I would never spend my money to have one as my personal sports car. I have come to appreciate the Lotus brand since they engineered our LT5 and fought the fight to get her done and put in production. This is a thread about DOHC v OHV so I dont know how it got to where it is now. I like this site because of the information obtained from fellow zr-1 enthusiasts and the willingness to help by so many members. It is a site I visit every day but if this the result of me expressing my opinion then I will refrain in the future and will stop posting or visiting again. This is a personal hobby so I take my liberties with what I do and how I do it so my opinions are solely mine
and nobody has to agree with them. I live by rules everyday on my job and in almost every other phase of my life but not my sportscar and car hobby which is my release. I hope you are happy with your euro cars or whatever you have but lets keep the european flag waving to a minimum in a Corvette site. I will not post on this thread any more.

[edram454]

And it’s not just Ferraris and Porsches. He also doesn’t like the “lousy LT4 car� (see post #11 ). And he’s certainly not impressed by the LS2 or LS3 and doesn’t FEEL that the LS7 is bulletproof (see post #6). I guess the only engine worth buying that any manufacturer ever produced was the LT5.

I will reply to you. I have had supercharged Fords, big block chevys, small block chevys and ls engines. I was a big fan of the ls7 427 small block ls motor but like I posted I have seen too many losing oil pressure and it wasnt because of high miles. The LT4 is a good engine but not my preference for a hot small block. The ls1,2,3 are good engines and make enormous power when they are modded but they have lots of valve train noise,, ticking... issues. It wasnt until I installed a supercharger that my ticking went away or maybe the supercharger drowned out the noise. Those engines do impress when they are boosted. None of those have the sophistication of the lt5. I am very picky when I chose the car and engine combo of my choice because it is my right and its my enjoyment. I can say of you that you like and accept anything that turns over. I am surprised that you just want to pile on to that other guys comment. I would certainly not consider you a friend if I ever saw you at some event. I guess you can go back to your ls1tech website. Now I am done.

[spork2367]

Listen spork2367, I am offended by your bigot comment. This is a corvette forum and those are my personal views and preferences of the Corvette. I know more about Zora Duntov than you will ever know since I studied his life and career and made it a point to meet him and Elfi on a few occasions. What does my view of zora or anybody else have to do with my sports car preference?? I dont appreciate your comments. You sound like you should be in some European car forum not on a Corvette forum. Does the fact that I don't like foreign cars make me bigoted? I appreciate the engineering invested in some of those cars but like I said, I would never spend my money to have one as my personal sports car. I have come to appreciate the Lotus brand since they engineered our LT5 and fought the fight to get her done and put in production. This is a thread about DOHC v OHV so I dont know how it got to where it is now. I like this site because of the information obtained from fellow zr-1 enthusiasts and the willingness to help by so many members. It is a site I visit every day but if this the result of me expressing my opinion then I will refrain in the future and will stop posting or visiting again. This is a personal hobby so I take my liberties with what I do and how I do it so my opinions are solely mine
and nobody has to agree with them. I live by rules everyday on my job and in almost every other phase of my life but not my sportscar and car hobby which is my release. I hope you are happy with your euro cars or whatever you have but lets keep the european flag waving to a minimum in a Corvette site. I will not post on this thread any more.

I will reply to you. I have had supercharged Fords, big block chevys, small block chevys and ls engines. I was a big fan of the ls7 427 small block ls motor but like I posted I have seen too many losing oil pressure and it wasnt because of high miles. The LT4 is a good engine but not my preference for a hot small block. The ls1,2,3 are good engines and make enormous power when they are modded but they have lots of valve train noise,, ticking... issues. It wasnt until I installed a supercharger that my ticking went away or maybe the supercharger drowned out the noise. Those engines do impress when they are boosted. None of those have the sophistication of the lt5. I am very picky when I chose the car and engine combo of my choice because it is my right and its my enjoyment. I can say of you that you like and accept anything that turns over. I am surprised that you just want to pile on to that other guys comment. I would certainly not consider you a friend if I ever saw you at some event. I guess you can go back to your ls1tech website. Now I am done.

Wow. Grab a beer and take two steps back. I called you bigoted because of your intolerance for foreign vehicles. Although now your lack of tolerance for the views of others seems just as bad.

My opinion is no more right or wrong than your opinion. However your opinion is monstrously hypocritical. You opine about your perceived superiority of American products and even essentially admit that it is out of ignorance that you want to think that (i.e. no logic or evidence you just want to think they're better).

Your lack of logic is telling you that the greatest American sports car engine ever created was one that was designed by Brits using European technology. It's probably the least American V8 Chevy ever built. If you want to say it's YOUR favorite sports car engine, that is fine. But that wasn't the first thing you said. Your first post on the subject was a relatively baseless criticism of Ferraris and Porsches.

And now you're ready to say none of us could be friends because we're just pointing out that your argument doesn't seem logical and we want to discuss things other than just the LT5? Don't worry, I don't think any of us will be tracking you down for a spirited discussion at any Corvette functions...

[edram454]

thats right rude dude, you did call me bigoted because of my opinion. who are you to insult and judge somebody because he is expressing his opinion. you tossed the first insult and you think by including the membership that they will all back you. Many members dont like european cars and some do because they are allowed to have a preference or an opinon and not be insulted and accused of being a bigot based on there sportscar preference. I am always rooting for the Americans even thought they were behind in DOHC technology and yes it was built by Lotus and it is a good engine. Its your opinion that my likes and dislikes are baseless because THEY DONT AGREE WITH YOURS!! You made you the forums critic of personal opinions. Go back to your rat hole and polish your yugo. I hope the moderator cleans this crap up. time for another topic but PLEASE DONT HAVE AN OPINION BECAUSE YOU WILL BE OPEN TO INSULTS BY OUR FORUM CRITIC MODERATOR.

[XfireZ51]

All right gentlemen, let's take this thread back to the subject it was meant for.
The word bigot may have been a poor choice of words although I am certain spork did not intend it in the colloquial sense. He appears to be pointing out an apparent inconsistency in edram's argument re: American hardware.
Now that we have "discussed" that, let's move on to what so far has been a great exchange of views. Let's keep it technical and factual.

[edram454]

Thank You.

[Kevin]

Except Ford is banking their future performance on the 3.5 liter ecoboost V6. It's in their new GT concept and in the Raptor. Removing the V8 from the Raptor, a pickup truck, is the writing on the wall. So GM really missed the boat on a DOHC V8. But it didn't really matter because the LS was a cheaper more reliable motor that was cheaper and easier to get power out of than any of the DOHC Ford engines.

The Corvette won't ever see a DOHC engine in production. It simply would cost too much. They want supercar performance on a budget. Ferrari and Lamborghini can continue to build V10 and V12 monsters because those buyers aren't concerned with gas mileage or cost.

more reliable?

[Kevin]

why are there discussions praising ferraris and porsches in this forum. As a Corvette enthusiast, I hate Ferrari's and Porsches to death. I would never own or desire one. I would buy one just to resell it and make some money. Ferraris are buzz bombs and make their power in extremely high rpms and little displacement and now with multiple turbos, the porsches have that flat six with many pounds of boost.. they are refined but frankly bore me to death... dont like the sounds they make and the ridiculous price tags are staggering... some people just crap out money because they can... If I didnt have a Corvette I would not have another sports car period. That is just the way I roll...

ed ramos #3028

sorry ed but I disagree. My neighbor has a 2005 911 that's awesome, parts of the interior are a little low rent but at this point it's a $30,000 car that's reliable, quick and handles awesome. The two ferrari's I've driven have enough power to be fun everywhere. The 328 is probably my favorite. It's light, it's nimble, it's not all that fast but at this point it's nearly 30 years old, no one's buying these for their performance. His TR is no slouch either. I like all cars, not just corvettes

[Kevin]

Ok, both of you suck it up and move on, you're both in violation of forum rules and I'm not above putting you both in time out. Now either keep this on track or don't post. I don't really care either way but if you resort to personal attacks I'll just ban you both

[5ABI VT]

Dohc just looks prettier .. Enough for me !

[spork2367]

more reliable?

Was the LS more reliable than the DOHC Ford 4.6, probably. It kind of depends whether you're talking about the production line version or the hand built SVT version. More reliable than the single overhead cam three valve...almost certainly.

why are there discussions praising ferraris and porsches in this forum. As a Corvette enthusiast, I hate Ferrari's and Porsches to death. I would never own or desire one. I would buy one just to resell it and make some money. Ferraris are buzz bombs and make their power in extremely high rpms and little displacement and now with multiple turbos, the porsches have that flat six with many pounds of boost.. they are refined but frankly bore me to death... dont like the sounds they make and the ridiculous price tags are staggering... some people just crap out money because they can... If I didnt have a Corvette I would not have another sports car period. That is just the way I roll...

ed ramos #3028

This was the post that started the mess. It's completely irrelevant to any of the numerous discussions at hand and certainly came across as you being offended that we were discussing technology and reliability in terms of other manufacturer's engines.

We could all bury our heads in the sand and pretend they don't exist, but those are exactly the cars that GM is looking at when they are deciding what changes to make on the Corvette to keep it competitive in the market. No one was telling you that you had to own one.

Corvettes are an amalgamation of high end European technology, European and American styling, and American brute force. I'll be honest in that I can't understand how you can love the LT5 so much without at least liking the engines that it borrowed technology from. If it weren't for them, the LT5 wouldn't exist. Even as it stood during production for the LT5, the crankshaft, pistons, rods, rings, liners, bearings, chain tensioners, and clutch were all made in the Uk or Germany.

I don't think my stance is rare in the automotive community. I just appreciate automotive technology. I own Land Rovers, Toyotas, drive a Dodge truck, wife drives an Acura, my plow truck is a big block Ford. Hell, I had a Toyota 1GZ-FE 5.0L V12 sitting in the back of my shop for a couple years.

Earlier in the thread you were just as happy to bash Chevy engines as well. The LT5 is amazing. That's why I have a ZR1 and why I'm rebuilding another LT5 engine currently. It just isn't the pinnacle of automotive technology. It wasn't in 1990 and it isn't now. It's just an awesome engine that broke the Corvette engine mold for 5 glorious years.:cheers:

[BigJohn]

What happened to the 5.0L V12?


:icon_boun

[spork2367]

What happened to the 5.0L V12?


:icon_boun

Sold it to some guy from Rochester who picked it up in his wife's minivan...lol.

It was a cool engine, but I didn't have the time to put it in something so I let it move on to someone who had the time. VERY cool engine. Dual computers and redundant systems so if one failed it would basically run like an inline 6 cyl. Continuously variable valve timing on the intake valves, variable length intake runners. 6 bolt mains, forged crank.

Best part....280 ft. lbs. of torque at 800 RPM!

[WARP TEN]

Dohc just looks prettier .. Enough for me !
I agree--good looking engines that don't have to hide under plastic. Before my first ZR-1 in 1994, I owned a 1989 Ford Taurus SHO as much for the look of the Yamaha engine as for any slight performance edge it had. But in its day it was a great company car for me. --Bob

[John Boothby]

"my plow truck is a big block Ford."

Whats a "plow truck"? (ha ha") Us guys out here in the west want to know? (no snow here!)

Just kiddin

[XfireZ51]

I agree--good looking engines that don't have to hide under plastic. Before my first ZR-1 in 1994, I owned a 1989 Ford Taurus SHO as much for the look of the Yamaha engine as for any slight performance edge it had. But in its day it was a great company car for me. --Bob

Owned 4 of these. great car.

[spork2367]

I agree--good looking engines that don't have to hide under plastic. Before my first ZR-1 in 1994, I owned a 1989 Ford Taurus SHO as much for the look of the Yamaha engine as for any slight performance edge it had. But in its day it was a great company car for me. --Bob

I just flipped a 1998 V8 SHO with 173,000k a couple months ago. Had a check engine light because the little gear motor that opened the secondary intake runners had a broken gear. Machined a new gear and sent it down the road. Both SHOs were cool cars.

[5ABI VT]

Here's my thoughts on on high end exotic cars.. I absolutely love them and I'll try my hand at explaining why.

The big 3 are fully capable of producing a motor similar to the Ferrari v12 I mentioned earlier. Why don't they? Cost. PROFITS. They are making billions doing what they do and there simply isn't a need to design complex engines. Again, they are fully capable, it's not rocket science. Building cars is a business first and foremost and it's all about profits.

Ferrari on the other hand.. Sell their cars for what they do because that's what it costs to design and engineer their vehicles in low volumes at the limits of modern day technology and materials because that is a part of its appeal to its customer base. The latest and greatest in technology.

The ls7 for example is cammed with a fuel economy and emissions cam for torque from the factory. An equivalent 7.0L Dohc motor can make a ton of torque down low and make a ton more hp up top as well. Why do ferraris not cam for lower Rpms ? Because large amounts of torque down low simply isn't needed for performance. Gears can add torque , gears can't add hp. So they are cammed and designed for top end hp and torque.

To me engines are air pumps. Dohc trumps pushrod everywhere except cost and simplicity (and packaging). The high end engines are cammed and geared for top end and max speed.. They don't come with a .50 Prius 6th gear that we have in the ZF. They simply could do that if they wished but they don't.

I'm rambling here lol.

[XfireZ51]

I just flipped a 1998 V8 SHO with 173,000k a couple months ago. Had a check engine light because the little gear motor that opened the secondary intake runners had a broken gear. Machined a new gear and sent it down the road. Both SHOs were cool cars.

Did you weld the cam sprockets to the cam?

[spork2367]

Did you weld the cam sprockets to the cam?

Nope, previous owner beat me to it.

[edram454]

I accept your opinion and that is great that you like European cars. I have driven a porsche 930 turbo and have owned 3 audi's since my ex wife liked them. I am not a stranger to euro or asian cars. As far as a sports car 2 seater I would only own a Corvette. I could buy any other car but I just feel at home in a corvette. There are euro cars like the Aston Martin, supercharged Jag, Mercedes SLR etc.. that are wonderful cars but I would not own one. I feel that the German cars are just way to overpriced so i couldnt drop that kind of coin for a german car without warranties. My last brake job on my Audi A4 was $2,300.00 to replace pads, rotors and calipers since you cant turn audi rotors etc... just too much money for a not so good car. I am glad there are people out there buying all kinds of cars so it keeps the hobby going. I like the Ultima GTR with a American V8 stuffed in it or maybe even a stroked LT5 inside. I did say I hate Ferrari's and maybe that is a bit harsh but in reality I wouldnt own one thats all. I dont like Porsche's not even a little bit. To me just a overpriced Karmen Ghia on roids. If I wanted a little car then I would invest in a ERA Cobra continuation car with a 700 hp supercharged Ford Coyote inside. Now thats fun and its DOHC!! Of course for everyday driving I enjoy American luxury cars. I have had many Lincolns. I sold my Lincoln Continental with a DOHC intech engine that ran great. Now have a low mileage Lincoln Town Car luxo barge. Gotta love it. I go from my Lincoln to my ZR1 so I got the best of both worlds. Thanks for you comment.

ed ramos #3028

[XfireZ51]

And Ed, thank you for your opinion as well.

[5ABI VT]

I accept your opinion and that is great that you like European cars. I have driven a porsche 930 turbo and have owned 3 audi's since my ex wife liked them. I am not a stranger to euro or asian cars. As far as a sports car 2 seater I would only own a Corvette. I could buy any other car but I just feel at home in a corvette. There are euro cars like the Aston Martin, supercharged Jag, Mercedes SLR etc.. that are wonderful cars but I would not own one. I feel that the German cars are just way to overpriced so i couldnt drop that kind of coin for a german car without warranties. My last brake job on my Audi A4 was $2,300.00 to replace pads, rotors and calipers since you cant turn audi rotors etc... just too much money for a not so good car. I am glad there are people out there buying all kinds of cars so it keeps the hobby going. I like the Ultima GTR with a American V8 stuffed in it or maybe even a stroked LT5 inside. I did say I hate Ferrari's and maybe that is a bit harsh but in reality I wouldnt own one thats all. I dont like Porsche's not even a little bit. To me just a overpriced Karmen Ghia on roids. If I wanted a little car then I would invest in a ERA Cobra continuation car with a 700 hp supercharged Ford Coyote inside. Now thats fun and its DOHC!! Of course for everyday driving I enjoy American luxury cars. I have had many Lincolns. I sold my Lincoln Continental with a DOHC intech engine that ran great. Now have a low mileage Lincoln Town Car luxo barge. Gotta love it. I go from my Lincoln to my ZR1 so I got the best of both worlds. Thanks for you comment.

ed ramos #3028


I have owned a few german cars, VW and a BMW. I sold them because like you mentioned.. they require a fair bit of $$ for maintenance. Im a DIY kind of guy so none of my cars has ever seen a dealer or shoppe (fingers crossed) for the last 15 or so years and hopefully never will. Turning rotors is a fraud in the auto industry in my opinion. it should never be done. $2300 sounds like a lot but if it were me and priced out accordingly I probably could have picked up a used brembo kit or retrofit from another vehicle for the car for that amount scavenging the forums for those cars. Of course I will admit that I do appreciate the level of refinement they provide, its just not in my income range to be able to just drop one off at a dealer and say service it. I have yet to drive anything american that compares to even my e46 M3 in terms of refinement. Even my passat wagon.. puts my ctsv to absolute shame in terms of design, engineering and refinement. But I chose to buy a ctsv because its a pickup truck drivetrain in a 4 door chassis and its cheap to maintain and modify/upgrade when repairs are needed and is a more diy friendly vehicle.


If I had a LOT of money.. I would buy a blue c6 ZR1, paint the roof and b- pillar blue, lower it on coilovers and add some HREs. I would pull the LS9 and sell it to someone looking to do a restomod, and I would plop a fully built no expense spared LT5 in there:-D. i would also enlarge the window on the hood for obvious reasons :)

[Tony Davila]

If I had a LOT of money.. I would buy a blue c6 ZR1, paint the roof and b- pillar blue, lower it on coilovers and add some HREs. I would pull the LS9 and sell it to someone looking to do a restomod, and I would plop a fully built no expense spared LT5 in there:-D. i would also enlarge the window on the hood for obvious reasons :)

-If you put a LS in a 90-95 ZR-1 or an LT5 into the latest ZR1 does that still make it a ZR-1/ZR1? So is it the engine that makes it what it is or is it the whole package?
-If you remove the factory motor is it still a ZR-1/ZR1?:confused: DOHC to Single cam or vise versa, I think I would see an LS9 into a C4 before I see a LT5 into a C6 ZR1.

[Dime]

-If you put a LS in a 90-95 ZR-1 or an LT5 into the latest ZR1 does that still make it a ZR-1/ZR1? So is it the engine that makes it what it is or is it the whole package?
-If you remove the factory motor is it still a ZR-1/ZR1?:confused: DOHC to Single cam or vise versa, I think I would see an LS9 into a C4 before I see a LT5 into a C6 ZR1.

Can't deny it's an original idea! =D>

[XfireZ51]

Keep the LS9 block. Replace heads w MMR DOHC heads for LS motors. Easier swap.

[KILLSHOTS]

I have owned a few german cars, VW and a BMW. I sold them because like you mentioned.. they require a fair bit of $$ for maintenance. Im a DIY kind of guy so none of my cars has ever seen a dealer or shoppe (fingers crossed) for the last 15 or so years and hopefully never will. Turning rotors is a fraud in the auto industry in my opinion. it should never be done. $2300 sounds like a lot but if it were me and priced out accordingly I probably could have picked up a used brembo kit or retrofit from another vehicle for the car for that amount scavenging the forums for those cars. Of course I will admit that I do appreciate the level of refinement they provide, its just not in my income range to be able to just drop one off at a dealer and say service it. I have yet to drive anything american that compares to even my e46 M3 in terms of refinement. Even my passat wagon.. puts my ctsv to absolute shame in terms of design, engineering and refinement. But I chose to buy a ctsv because its a pickup truck drivetrain in a 4 door chassis and its cheap to maintain and modify/upgrade when repairs are needed and is a more diy friendly vehicle.


If I had a LOT of money.. I would buy a blue c6 ZR1, paint the roof and b- pillar blue, lower it on coilovers and add some HREs. I would pull the LS9 and sell it to someone looking to do a restomod, and I would plop a fully built no expense spared LT5 in there:-D. i would also enlarge the window on the hood for obvious reasons :)
If you had a LOT of money, why not just go all the way and install a Mercury Racing QC4v?

That would be a pretty quick 'Vette.

[Paul Workman]

Keep the LS9 block. Replace heads w MMR DOHC heads for LS motors. Easier swap.

That would be interesting...:icon_thum But, IIRC, the MM DOHC heads were a "work in progress"; that is to say that VVT and DI was not yet accommodated. Do you (or anyone) have some "fill-in" info in that regard?

[XfireZ51]

That would be interesting...:icon_thum But, IIRC, the MM DOHC heads were a "work in progress"; that is to say that VVT and DI was not yet accommodated. Do you (or anyone) have some "fill-in" info in that regard?

Well but the LS9 didn't have either. The heads were designed to work w the LS architecture not the LT, at least not yet. MMR showed them at SEMA on an LS block. Its worth an inquiry. I'm sure they ain't cheap but neither would a LT-5 swap be. On the other hand, we know the LS block fits and works w the PCM.

[edram454]

I have owned a few german cars, VW and a BMW. I sold them because like you mentioned.. they require a fair bit of $$ for maintenance. Im a DIY kind of guy so none of my cars has ever seen a dealer or shoppe (fingers crossed) for the last 15 or so years and hopefully never will. Turning rotors is a fraud in the auto industry in my opinion. it should never be done. $2300 sounds like a lot but if it were me and priced out accordingly I probably could have picked up a used brembo kit or retrofit from another vehicle for the car for that amount scavenging the forums for those cars. Of course I will admit that I do appreciate the level of refinement they provide, its just not in my income range to be able to just drop one off at a dealer and say service it. I have yet to drive anything american that compares to even my e46 M3 in terms of refinement. Even my passat wagon.. puts my ctsv to absolute shame in terms of design, engineering and refinement. But I chose to buy a ctsv because its a pickup truck drivetrain in a 4 door chassis and its cheap to maintain and modify/upgrade when repairs are needed and is a more diy friendly vehicle.


If I had a LOT of money.. I would buy a blue c6 ZR1, paint the roof and b- pillar blue, lower it on coilovers and add some HREs. I would pull the LS9 and sell it to someone looking to do a restomod, and I would plop a fully built no expense spared LT5 in there:-D. i would also enlarge the window on the hood for obvious reasons :)

You are right about the refinement of the euro cars and high end asian cars. they put alot more money in those cars but it tends to price out a lot of people who would like to own one but cant afford it. The Corvette is relatively affordable to middle income Americans. It is not to hard to save a little and buy one and be in the hobby. It is only recently that a Corvette has sported a real nice interior with the c7. It is a semi-high quality interior instead of the low quality it has put in virtually all other Corvettes. the Corvette constantly gets ripped by reviewers on the cheap seats and interiors and I have to agree. For that, thank God for the c7. I think a blue zr1 c6 is a fantastic car. An absolute gem that really hauls azz. I would love one of those cars and if I had room, which I dont, I would try to acquire one. You are right about the brembo brake kit for that audi but I was out of town so I just had the car picked up by the mechanic and paid for the work. I eventually gave her that car in the divorce that way i got rid of problems in one swoop. by the way, I love your youtube video and the sounds you car makes. It made me call corsa and order and corsa system for my car. It is being installed and I would be happy if it sounded like yours. I dont have gears or the fidanza flywheel but I do have agressive porting with long tube headers, no cats and custom chip so it should sound similar. I drive around with my back window slightly propped open with a corvette gadgetman latch just so I can hear that sound really loud. I also liked your shifter so I went out and bought a hurst shifter with custom shifter ball in black. All your mods are great so keep up the good work.

ed ramos #3028

[XfireZ51]

An article that's very much "on point" with our discussion here. Be worth following it. Coyote v LS3.

http://www.enginelabs.com/engine-tech/engine/preview-ls3-vs-coyote-budget-engine-shootout/

[KILLSHOTS]

Unfortunately, I think, it’s “on pointâ€� in more ways than one. IMHO, this article is not a good argument for a DOHC platform. First, they had to handicap it by starting with a truck engine for the Coyote, because a truly-comparable Mustang engine is far too expensive to be built vs. the LS3. That’s red flag #1. Then, they acknowledge that the Camaro’s (and Corvette’s) pushrod LS3 produces more power in stock form than the Mustang’s DOHC Coyote in stock form, so they handicap it again by throwing a HP per liter parameter into their testing criteria to save the Coyote’s bacon. Ouch, that’s red flag #2. Does anyone who’s being truly objective really care about HP per liter, as opposed to just the amount of power produced? HP per liter, in a case like this, is nothing more than a BS qualifier, an excuse, vis-Ã*-vis, “Well, maybe my Mustang only has 420HP but it’s NOT FAIR, because your Camaro has more cubic inches!â€� And just as an aside, the smaller displacement Coyote is a MUCH larger and somewhat heavier engine than the LS3, which begins to shine a light on the potential packaging limitations of a modern DOHC layout. This is important, because if GM designs a Corvette around such a large and heavy engine, then it also needs to consider how that car's dynamics may suffer, especially in this age of rapidly rising CAFE standards, thanks to the greenies.

Please understand that, as I’ve said before, I love the LT5…wouldn’t have owned a Z unless that was fully true. But it seems to me that we’re generally falling into 2 camps here: those who really want GM to move back toward DOHC power for the Corvette, and those who believe that it’s generally not currently viable from a cost perspective. Regardless the final dyno numbers, I think that the entire premise of this particular article does a better job of validating the latter group’s argument.

[mike100]

The Coyote is only 430 lbs if I recall correctly. It is certainly not the cheapest way to make an 11 second street toy, but there are a couple of useful advantages that I consider:

1) True dual cam VVT. The powerband from 300 cubic inches is really amazing and you don't have to always shift to keep it above 4000 rpms like you do on an LS engine when you get caught on the dull part of the low rpm power curve.
2) no surge of massive torque to blow off the rear tires as with large displacements. I find that this type of engine easier to drive a car at its limits than a big inch one.
3) There are sometimes intangible properties like an engines willing to change speed and rev although with the coyotes borrowed long stroke from the modular engines, the advantage might be for the LS. Just like diesels- they might have 800 lb/ft of torque, but they are locomotive slow to rev up. My mustang is geared so much lower than my vettes- it certainly seems faster to rev out- the 5.0 engine takes it in stride and seems balanced better. (maybe not better than the LT5, but certainly than the LS3).

conclusion: the transmission might be the more important discussion, but true variable valve timing raises the area under the curve for torque so that coupled with close ratio gearing is really hard to beat.

[XfireZ51]

The article was not cited in order to score points for the OHC motor. It was put there as a source of greater objectivity than may be displayed on this forum, and that includes me. I am interested in seeing what they come up with.
What would be a really interesting "comparo" would be taking an LSsomething and dropping the MMR DOHC LS heads on it. Same block, but different valvetrain architecture and even same induction. THAT would make for a very interesting test.

[Paul Workman]

In a pure scientific (DOHC v OHV) discussion, when making comparisons of examples with varying degrees of critical variables, there has to be some mollification of differences - especially in something as critical as displacement. Another example is comparing a NASCAR motor to one designed to me emissions and perform equally well in city type stop and go traffic with the AC turned on as it does at WOT.

[FONT=&quot]Unfortunately, I think, it’s “on point� in more ways than one. IMHO, this article is not a good argument for a DOHC platform. First, they had to handicap it by starting with a truck engine for the Coyote, because a truly-comparable Mustang engine is far too expensive to be built vs. the LS3. That’s red flag #1.

Irrelevant to architecture analysis (DOHC v OHV)

[FONT=&quot]Then, they acknowledge that the Camaro’s (and Corvette’s) pushrod LS3 produces more power in stock form than the Mustang’s DOHC Coyote in stock form, so they handicap it again by throwing a HP per liter parameter into their testing criteria to save the Coyote’s bacon. Ouch, that’s red flag #2. Does anyone who’s being truly objective really care about HP per liter, as opposed to just the amount of power produced? HP per liter, in a case like this, is nothing more than a BS qualifier...*

"Does anyone who’s being truly objective..." really think displacement is irrelevant??

I agree that you're spot on when considering power/$$ and marketing. I mean after all, about 1/3 of ZR-1 owners admit to never pushing their LT5s beyond Gen-I SBC capabilities. The LT5's characteristics are pretty much moot if limited to 5500 or 6000 rpm.

But, $$ wise, the ZR-1 was X2 the price of the base Corvette when new, and pretty much the same is true today, except for some NCRS garage queens that push that to X3 perhaps. So, for some, and that includes all of us, $$ isn't the deciding factor, but rather determines how long one (like me) has to wait to be able to afford one!

And, one could question my saying so, but the "FBI" has taken home the team trophy for the fastest aggregate of 3 cars at a local Corvette drag race shootout event, 3 out of the last 4 years, plus the first year when we won but didn't register for trophies. I dunno... But, it might be a clue? (And there's no more scoffing from C5 or C6 owners when a "lowly C4" [I]with a ZR-1 badge on it comes to the line against one of their LSx bretheren...

So, the burning question is, what would be possible if GM did build contemporary DOHC V8? I'm w/ Dom: what does the LSx do with a set of MMR DOHC heads on it?? And, why are so many manufactures moving to the DOHC architecture w/ VVT and DI in spite of the drawbacks??

[KILLSHOTS]

In a pure scientific (DOHC v OHV) discussion, when making comparisons of examples with varying degrees of critical variables, there has to be some mollification of differences - especially in something as critical as displacement. Another example is comparing a NASCAR motor to one designed to me emissions and perform equally well in city type stop and go traffic with the AC turned on as it does at WOT.



Irrelevant to architecture analysis (DOHC v OHV)



"Does anyone who’s being truly objective..." really think displacement is irrelevant??

I agree that you're spot on when considering power/$$ and marketing. I mean after all, about 1/3 of ZR-1 owners admit to never pushing their LT5s beyond Gen-I SBC capabilities. The LT5's characteristics are pretty much moot if limited to 5500 or 6000 rpm.

But, $$ wise, the ZR-1 was X2 the price of the base Corvette when new, and pretty much the same is true today, except for some NCRS garage queens that push that to X3 perhaps. So, for some, and that includes all of us, $$ isn't the deciding factor, but rather determines how long one (like me) has to wait to be able to afford one!

And, one could question my saying so, but the "FBI" has taken home the team trophy for the fastest aggregate of 3 cars at a local Corvette drag race shootout event, 3 out of the last 4 years, plus the first year when we won but didn't register for trophies. I dunno... But, it might be a clue? (And there's no more scoffing from C5 or C6 owners when a "lowly C4" [I]with a ZR-1 badge on it comes to the line against one of their LSx bretheren...

So, the burning question is, what would be possible if GM did build contemporary DOHC V8? I'm w/ Dom: what does the LSx do with a set of MMR DOHC heads on it?? And, why are so many manufactures moving to the DOHC architecture w/ VVT and DI in spite of the drawbacks??
I understand the hypotheticals and don't necessarily disagree. My point is that GM has no incentive to produce another DOHC Corvette today. Sure, it would be really cool if they did. But it makes no financial sense and isn't necessary, considering the fact that the car is a world-class performer in all areas with a cheaper pushrod engine.

[Johnny5]

wow, reading only the first few pages and cracking up I have to add that I have a 91 Zr1 and my brother has a 2004 Z06 so i have experienced both DOHC and OHV engines/layouts. The z06 has more down low torque, more of a throw you back in your seat at low or any rpms where our LT5s have to rev up to get that adrenaline feel. His engine is hundreds of lbs less and way cheaper to build, maintain etc. Given our cars were KING until the C5 z06 came out. the z06 is faster and handles better but the LT5 has more potential. I have ported plenum/IH catback and a tune and I was neck and neck with the stock c5 z06 but he eats me up in the twisties. At the end of the day I love my car more bc of its rarity, group of people, car guys that actually know what a zr1 is, no blind spots, and I **** on my bro every chance i get by saying i can take my top off.....plus his girlfriend likes my car more lol. Long live the KING:proud:

[XfireZ51]

Your interior doesn't look like it was vacuum formed out of sheet plastic either.
Again, match up to his 405hp, then run beyond the 1/8 mile. See what happens.

[spork2367]

And just as an aside, the smaller displacement Coyote is a MUCH larger and somewhat heavier engine than the LS3...

And the coyote engines weight is up high. I've picked up a bare coyote block and it doesn't weigh anything.

[rkreigh]

true that Dave M "pushed the boundaries" and wen't world class when corvette was about to go extinct.

I like his style! Hoping the "new ZR-1" will be a DOHC mid engine TT car.

if so I'll be saving my butter and egg money and buying a used one (after it's under 100k buy in)

as for the ford. I'm not a fan but I respect what they've done with the new VooDoo flat crank engine emerging with well over 500 poinies and a legit 8k plus red line.

that to me is more exciting than slapping a blower on (heavy up top too isn't it!)

I love all corvettes, but GM does have the engineering talent to build another world beater. I don't think the new Z06 is it. hopefully the new ZR-1 will be!

GM again needs a "flag ship" give me that rear engine maint nightmare with a stout electic motor up front and let's give that "La Ferrari" (jeez what an uninspiring name) a run for it's money at a fraction of the cost.

not easy to do but that's exactly what the old ZR-1 did and it's time to do it again!

now where is that bean counter stick, oh, it left with Dave M !!!!

[XfireZ51]

And the coyote engines weight is up high. I've picked up a bare coyote block and it doesn't weigh anything.

I think the "packaging" advantages of the OHV motor and the LS, in particular, have been conceded. Nobody's arguing that. The premise of this thread is really how and what kind of power is available from each architecture. In my opinion, the Corvette will always be described w a "qualifier" as in "its the best Vette yet" until GM steps up and replaces what is seen as a "truck motor" w something more sophisticated. I think you can extol all the virtues of the LS motor and show how it performs BUT it wasn't until the LT-5 showed up that the rest of the world sat up and took notice. At that point, the chassis became the focus of requiring an upgrade.

[spork2367]

BUT it wasn't until the LT-5 showed up that the rest of the world sat up and took notice. At that point, the chassis became the focus of requiring an upgrade.

The rest of the world doesn't even know what the LT-5 was or how it was different. That's part of the reason the long term outlook sucked.

Most Corvette owners don't even know what it was. It was a blip on the radar.

If they had stuck with it there is no doubt that the Corvette would be a faster car today because of it. It would also be 50% more expensive.

[Paul Workman]

The rest of the world doesn't even know what the LT-5 was or how it was different. That's part of the reason the long term outlook sucked.

Most Corvette owners don't even know what it was. It was a blip on the radar.

If they had stuck with it there is no doubt that the Corvette would be a faster car today because of it. It would also be 50% more expensive.

Oh, I think the engineering world took notice - looking at the transfer of LT5 DNA to the LS series... Even if GM Power Train wanted to bury the LT5 (as "not invented here"). Also, marketing certainly capitalized on the ZR-1s styling - maybe NOT for the same reasons one might guess... But, reaffirmed just a couple weeks ago, there is a vibrant group of young drivers that are very aware of the LT5, what it is and it's history. A group of teenage or early 20s guys of the 'Fast and "Furrious" ' ilk took keen notice of my Z at a Morris IL car show. They took pictures from several angles and came over to ask me about it.

And, as they were leaving, one said he wanted to get a ZR-1 soon as he could afford it. It was refreshing!:-D

[KILLSHOTS]

I think the "packaging" advantages of the OHV motor and the LS, in particular, have been conceded. Nobody's arguing that. The premise of this thread is really how and what kind of power is available from each architecture. In my opinion, the Corvette will always be described w a "qualifier" as in "its the best Vette yet" until GM steps up and replaces what is seen as a "truck motor" w something more sophisticated. I think you can extol all the virtues of the LS motor and show how it performs BUT it wasn't until the LT-5 showed up that the rest of the world sat up and took notice. At that point, the chassis became the focus of requiring an upgrade.
The Stingray and Z06 are already viewed as world class automobiles. As spork also pointed out, nobody else even knows what an LT5 was; the only people who think the brilliant C7 has a "truck engine" are the ones on THIS website.

[spork2367]

Oh, I think the engineering world took notice - looking at the transfer of LT5 DNA to the LS series... Even if GM Power Train wanted to bury the LT5 (as "not invented here"). Also, marketing certainly capitalized on the ZR-1s styling - maybe NOT for the same reasons one might guess... But, reaffirmed just a couple weeks ago, there is a vibrant group of young drivers that are very aware of the LT5, what it is and it's history. A group of teenage or early 20s guys of the 'Fast and "Furrious" ' ilk took keen notice of my Z at a Morris IL car show. They took pictures from several angles and came over to ask me about it.

And, as they were leaving, one said he wanted to get a ZR-1 soon as he could afford it. It was refreshing!:-D

The engineering world 25 years ago...

A young driver who knows what the LT5 is today is rare.

[RICKYRJ1]

Car people on the other side of the pond knew and admired the LT5. This comes from friends/family (Italy, Portugal, Greece, Hungary) who live there. They thought GM/Corvette finally was stepping up. I'm still always amazed at Corvette guys who don't know anything about the C4 ZR-1/ LT5. It's not like the ZR-1 was a regular C4 with a decal pkg. & paint.

[XfireZ51]

Most of the people who appear to have an appreciation of the LT-5 re in fact younger people, even younger than the Millenials. And don't forget how the
ZR-1 was introduced. It was in Europe and w the European press. Maybe we could ask our European brethren their view. The V angle and bore spacing also indicated a proliferation of the LT-5 motor into other models. The fact that Powertrain doesn't even have an example of the LT-5 in the HQ speaks volumes about silo thinking that exists through this day.
You can't tell me McClellan isn't a bit bitter about the LT-5 altho he'd never say anything like that. And costs would have been dramatically reduced with volume. If the LS wasn't a truck motor, you wouldn't have $50K C7s today either.

[spork2367]

Most of the people who appear to have an appreciation of the LT-5 re in fact younger people, even younger than the Millenials.

I'm 32 and have a zr1, an extra LT5 and about 7k worth of spare parts, so I'm one of those people.

I think this is due in part to the fact that many of the original buyers weren't car guys per se, they were buying them for investments. When that investment didn't pan out, they sold them to the second owners who were car guys.

[XfireZ51]

If you are a younger car enthusiast, the C4 ZR-1 represents an absolute steal in terms of performance and exclusivity. Particularly if you do your own wrenching. Some of the same reasons I'd love to have a Ford GT or a Pantera.

[RICKYRJ1]

I'm 32 and have a zr1, an extra LT5 and about 7k worth of spare parts, so I'm one of those people.

I think this is due in part to the fact that many of the original buyers weren't car guys per se, they were buying them for investments. When that investment didn't pan out, they sold them to the second owners who were car guys.

I tend to agree with ya on that. People buying now want the car, not the $$. :proud:

[Mystic ZR-1]

I'm 32 and have a zr1, an extra LT5 and about 7k worth of spare parts, so I'm one of those people.

I think this is due in part to the fact that many of the original buyers weren't car guys per se, they were buying them for investments. When that investment didn't pan out, they sold them to the second owners who were car guys.

Very true!!!

[Hib Halverson]

If you are a younger car enthusiast, the C4 ZR-1 represents an absolute steal in terms of performance and exclusivity. Particularly if you do your own wrenching. Some of the same reasons I'd love to have a Ford GT or a Pantera.

I tend to agree with ya on that. People buying now want the car, not the $$. :proud:

Unfortunately, actual market conditions do not support either statement. Used C4 ZR-1s are not selling well...with the exception of pristine, very low mileage 92-95s

[XfireZ51]

Unfortunately, actual market conditions do not support either statement. Used C4 ZR-1s are not selling well...with the exception of pristine, very low mileage 92-95s

Or purpley 95s?

[Fully Vetted]

If you are a younger car enthusiast, the C4 ZR-1 represents an absolute steal in terms of performance and exclusivity. Particularly if you do your own wrenching. Some of the same reasons I'd love to have a Ford GT or a Pantera.

The Pantera is the next car on my bucket list. When I decided to get another car I was torn between the Pantera and the ZR-1. I'm glad I went with ZR-1 but it only temporarily eased my desire for a Pantera. My Dad had a yellow '74 when I was growing up. It was one nasty car. Now that all of the electrical and overheating fixes are out they can be very dependable. And I can't remember the last time I saw one on the road.

[spork2367]

Unfortunately, actual market conditions do not support either statement. Used C4 ZR-1s are not selling well...with the exception of pristine, very low mileage 92-95s

They aren't selling, most ZR-1 and non ZR-1 C4s are priced entirely too high. It's a buyers market, but you have to keep an eye out for a truly good deal. There are a decent amount of the same C4s sitting around here on lots year after year.

They are cost effective to own in stock form, but aren't cost effective to modify at all. They aren't cost effective to repair or rebuild either.

If you want cost effective you buy a high mileage or blown C5, pull the engine and drop in a low mileage salvage engine.

The money I'll have into rebuilding the LT5 I'm working on, to stock form, would buy me a mid mileage LS3.

[pantera1683]

The Pantera is the next car on my bucket list. When I decided to get another car I was torn between the Pantera and the ZR-1. I'm glad I went with ZR-1 but it only temporarily eased my desire for a Pantera. My Dad had a yellow '74 when I was growing up. It was one nasty car. Now that all of the electrical and overheating fixes are out they can be very dependable. And I can't remember the last time I saw one on the road.

I once owned a 71 Pantera (#1683)...hence my username. It was great car and I modded that car to no end. I even replaced the 351 Cleveland with a 5.4L DOHC motor. I am quite certain I was the first to ever do it. It was such a fun car to own, modify, and drive. As expected, the prices have gone up considerably since I owned mine. I may even have pictures somewhere...

[Fully Vetted]

Very nice. Probably the only car I would have to consider as a trade for my Z.

Is that Hilborn injection I see?

[pantera1683]

Very nice. Probably the only car I would have to consider as a trade for my Z.

Is that Hilborn injection I see? Kinsler Injection.

[RICKYRJ1]

Unfortunately, actual market conditions do not support either statement. Used C4 ZR-1s are not selling well...with the exception of pristine, very low mileage 92-95s

The ZR-1 has gotten so much bad press over the years about no parts and mechanics not able to work on them. So if you are buying one now the main reason but not only is that you want one. Why else? your not getting rich flipping or parting them out, JMHO :handshak:

[XfireZ51]

Pantera an affordable exotic.