Point/Counterpoint: DOHC v OHV

[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 (aka Jag CX75)

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

[spork2367]

Originally Posted by rkreigh

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]

Originally Posted by XfireZ51

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