Prototype Engines

[USAFPILOT]

Didn't GM build some 450HP LT5's that were gong to be installed on the 96 and up ZR-1s before the canceled the LT5? Did any ever find their way out of GM to a private parties hands?

[Kevin]

grahm at lpe had several next gen lt5's, not sure where they went

[tccrab]

I'd heard that a few of these engines exist but I've never seen a picture of one.

TomC

[USAFPILOT]

I'd heard that a few of these engines exist but I've never seen a picture of one.

TomC

me either...they probably look the same, but I'd like to see.

[A1990]

There were going to be differences, one injector/cylinder, variable cam timing to name a couple. Looks different too. This picture is from the 2008 Gathering.

http://i285.photobucket.com/albums/ll75/djpatrickzr1/DSCN0157.jpg

[tomtom72]

At the 20th anni gathering over at JVD's BBQ I listened to Mr. Mclellan explain that they had a redesigned LT5 that was done to fit inside a C5. The motor was a clean sheet of paper because the C4 LT5 would not fit in a C5 as it was too tall and the C5 hood would hit our motors.

This next part I'm almost 100% positive of....Mr McLellan said that in 90/91 they had a C5 chassis, less the rear transmission as it wasn't ready yet, under cobbled together C4 body panels with a clam shell lowered to simulate the underhood clearance of the new C5. It was a test car to do testing on the C5 chassis & suspension, and it had one of these new LT5's in it and they were driving it around BG to test it! I swear I heard Mr. McLellan say that....I nearly fell off of my chair as he went on to list some of the improvements to the motor and that Lotus did this new motor specifically for the C5 program. It was rejected ofcourse due to costs?

It had the specific bore spacing that Lotus had wanted to use to suit the 4 valve head, it was to be a MAF system, one injector per cylinder, VVT, it met emissions for OBDII, it had no gas guzzler tax including the ZO6 version of the motor, and they even had a version to use in the C5 ZR-1. I think I remember that the ZO6 version was to have 600 hp, and the ZR-1 version was to be close to 700 hp w/ a gas guzzler tax ( I'm not 100% sure on that as I think I was crying by then! ) and that the regular corvette base LT5 was 450 hp! Oh, forgot this part, Mr. McLellan said that all these motors were N/A.....I think that's why I was crying or writhing in pain by then. Can you imagine what the reception would have been like for the C5 with 450 hp as the standard motor?!? I mean the car was a hit with the new chassis.

I know one thing....when I was looking to buy back into the corvette hobby back in 04 the only C5 that held my interest was the ZO6....the "standard" vette not so much. I chose my car to spend my cash on, my 90. If the C5 had used the new LT5 I would have taken a loan to buy a new ZO6 rather than buy a C4 ZR-1....I know you can have me turn in my power key, but the C5 chassis is ( IMHO ) just that little bit better than the C4 chassis.

:cheers:
Tom

[USAFPILOT]

I'd like to think that Lotus probably owns the rights to the design of that LT5, but maybe GM is waiting for the patent to expire or something. I hope they go back to the DOHC with the next gen vette. Didn't they shelve plans to build a new DOHC family of engines right when the economy tanked and they took all the money from the fed to stay in business? I bet we see that ramp back up again soon.

[tomtom72]

My thoughts on Lotus having patent rights would be that they were owned by GM at the time the LT5 was developed. I got the impression from Mr. McLellan's talk that as soon as Mercury Marine was making production motors Lotus started making the next gen LT5 "prototype" motor for testing....which would mean that it belonged to GM.

The thing that always amazes me about the LT5 is how quickly the motor went from an idea to a motor legal for use in a production car. Them guys were burning some serious midnite oil! Heck the LSx development started around the same time conceptually. I'm sure Mr. McLellan mentioned at the BBQ that by 90 or 91 it wasn't available to use in C5 test cars yet because I remember him saying that there were two chassis test cars. The LT5 one, and the other had an L98 in it. They used an L98 because the motor dimensions were almost the same as what was going to be the LSx.

I will add this as it is just my impression from listening to Mr. McLellan's talk at the BBQ. He wanted the next gen LT5 before the LSx was even out of prototyping so he could have it for the C5. I mean his crew designed the C5. I got to say that this is just my speculation. He never said this at the BBQ, but if you were there and were watching him while listening to him...well I got the impression that the new LT5 & the C5 was the direction he wanted corvette to go in for the future. JMHO.

Just as a fwiw. His book, "Corvette from the Inside", is worth reading along side the HOTB....it kind of gives a more complete picture of not just our cars, but the engineering philosophy that makes the corvette.

:cheers:
Tom

[bdw18_123]

Cool picture, A1990! I've never seen a picture of a gen II LT5. Wasn't even sure if any of those motors existed. Got anymore pics of it?

[USAFPILOT]

I just wonder if that Gen II LT5 would actually be GM'snew line of DOHC engines that were cancelled a while back. Were they bringing it back or were they just doing something different with the Northstar V8?

[tomtom72]

I just wonder if that Gen II LT5 would actually be GM'snew line of DOHC engines that were cancelled a while back. Were they bringing it back or were they just doing something different with the Northstar V8?

This is just my opinion to your Q. I drove one of those STSv's w/the blown N* and I thought for a fairly big car it was pretty good. I drove it for about 15 minutes so what can I say. I also never drove anything that was forced induction so what would I really know, right?

I guess money troubles could have been the cause of the LT5 and the N*'s death and lack of development? I'm thinking that the LT5 program from 86 was allowed to go forward to help not just corvette, but also to maybe show the way to the Olds & Caddy guys how to do a DOHC/4V motor? The Aurora & N*'s came after our LT5 was ready for production, right? I figure that the corvette guys broke the trail & smoothed the way for the Olds & Caddy guys? I mean why waste $$ on three development programs right?

[Z51JEFF]

I'd like to think that Lotus probably owns the rights to the design of that LT5, but maybe GM is waiting for the patent to expire or something. I hope they go back to the DOHC with the next gen vette. Didn't they shelve plans to build a new DOHC family of engines right when the economy tanked and they took all the money from the fed to stay in business? I bet we see that ramp back up again soon.

I would venture to say that G.M. owns EVERY aspect of the LT5.

[A1990]

Cool picture, A1990! I've never seen a picture of a gen II LT5. Wasn't even sure if any of those motors existed. Got anymore pics of it?
Check out issue 14, June 2008 of the Heart of the Beast. Lots of pictures and information on the engine. It was variable cam timing...

[xlr8nflorida]

Would make a good Yacht Anchor! Looks kinda heavy :cheers:

http://i285.photobucket.com/albums/ll75/djpatrickzr1/DSCN0157.jpg

[bdw18_123]

Check out issue 14, June 2008 of the Heart of the Beast. Lots of pictures and information on the engine. It was variable cam timing...

Well, I would but I don't have any of those. 2008 was before I had a ZR-1.

[ScottZ95ZR1]

Newsletters back to 2004 are available in the members section.

[WB9MCW]

http://i126.photobucket.com/albums/p110/HAMMERHATE/LT-5GENII.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/LT-5GENIIA.jpg

[bdw18_123]

Thanks for posting up those pics, WB9MCW!

[cvette98pacecar]

Now that engine would be a lot easier to keep clean.

[Kevin]

non-factory prototype but does anyone know what came of:
http://i.imgur.com/7nXcW.jpg

[cvette98pacecar]

non-factory prototype but does anyone know what came of:
http://i.imgur.com/7nXcW.jpg

Now that is a great looking plenum.

[GOLDCYLON]

http://i126.photobucket.com/albums/p110/HAMMERHATE/LT-5GENII.jpg

http://i126.photobucket.com/albums/p110/HAMMERHATE/LT-5GENIIA.jpg


That plenuim looks very L-98ish

[Corvettes White]

Boy am I slow. After all these years, I just noticed that the motor in the collage at the top of this site is a Phase III motor. LOL George

[Kevin]

I was looking over some old BG pics and I found another pic of the plenum I posted before and I think the car that it was in

http://i190.photobucket.com/albums/z181/cigarmanpa/vettes/BG0681Large.jpg

http://i190.photobucket.com/albums/z181/cigarmanpa/vettes/BG0675.jpg

sure would make working under the plenum easier

and i kinda like it without the high mount

[tomtom72]

Boy am I slow. After all these years, I just noticed that the motor in the collage at the top of this site is a Phase III motor. LOL George

You know I never noticed that fact either! :o

[tomtom72]

Hey Kevin, you have any more picts? There is alot more going on here than just another design/idea for the plenum.....his I/H's are either switched left for right or some one did a new I/H to go with that plenum....and they maybe did it to give the injectors a better shot to the valves???

Saweeeet stuff! Thanks for posting the picts!:thumbsup:

:cheers:
Tom

[Kevin]

Tom,
I'll have to look, I was pretty busy talking to the guy who's name I can't remember. The center section of the plenum came off and you could access everything under it very easy....of course I don't remember what was under it anymore. Let me look and see what I an find.

unfortunately I don't have anymore but I do know that I need to get back to bg for the first time in 6 years here soon. I'm gona go mope in the corner now for a while

[limey]

That intake is Bk's work.
FU will know eh Frank :-)

[Kevin]

That intake is Bk's work.
FU will know eh Frank :-)

that name was kicking around my head when i looked at it too

[tomtom72]

Kevin, thanks for posting up what you had. Okay from the back corner of the classroom where all the dummies sit....who is BK?....I know I'm a member of the freshman class of 04 ( very late 04 ) so I'm among the ZR-1 history stunted people!:mrgreen:....but I'm trying hard to catch up!

Oh, don't mope in the corner. There is always next year at BG. You our event isn't going away any time soon either. Hey besides there is always Carlisle this year.

:cheers:
Tom

[Kevin]

Bill Kirchoffer is the name. i'll let frank fill in the story if he wants. i know it was certainly interesting to me when i heard it.

I will be at carlisle this year...first time i've been able to make it in 3-4 years. my car was there last year though, or was it the year before? carlisle is an awesome time....though Ron and I have never been roped INTO a bar in Carlisle like we were in BG. Carlisle is a fun time, but BG is always where it's at for me

[Bob Eyres]

Wwwhaaat?...holy crap, that's cool. I had no idea that was in development. It looks like a 21st. century version of the LT5.
Come on guys, I couldn't make it to Bowling Green. What's the story on this thing. Inquiring minds want to know !!
Didn't anyone get this presentation on video?
Graham, what are the production plans for this?

My take on the pix- Heavier?- probably not much.
Bulkier for sure, that's a long throw on those runners. They look like freakin' drainpipes compared to a stock LT5 plenum.
Will it fit under a stock ZR-1 hood? At a glance you can tell, no bloody way. That's a "high rise", daddy.
From the other pic, it looks like a new head configuration too. Huh..oh, does that mean you'd have to buy a whole new top-end. That means major $$$$$.
But it also might mean new valve train architecture that might finally mean the vicious 8,500rpm I've always dreamt about.:dancing

To me, It looks like it would flow so much air that it would only be really effective on big inch stroker LT5's. Graham, is that the case? If so, that's a shame. Because with 32 valves, a lot of us would like to bring a naturally aspirated old stock 350 short block to the party and kick a lot of 21st century cars a$$es. :cheers:
We don't need no stinkin' blowers.

[mgbrv8]

Here you go Bob

https://www.youtube.com/watch?v=X-Z5oOIgv2o

David

[Tripler]

Found this on Youtube today . Maybe you guys have already posted this somewhere on the forum ...

;) ;) ;)

https://www.youtube.com/watch?v=JGBhM_iq2ro

[JaySS]

Always wondered what this was about:

"...with a prototype DOHC engine."

http://www.hotrod.com/how-to/engine/hrdp-0408-chevy-ls1-ls6-engines/

[grahambehan]

I'll just leave this here.

[A26B]

Ahhh, what would have been. So cool.

[RussMcB]

"Like".

[-=Jeff=-]

So Graham..

How does it drive?

[grahambehan]

So Graham..

How does it drive?

Don't know yet, had to get it running and sent it to Ken's for a show, haven't seen it since.

Graham.

[Paul Workman]

Ahhh, what would have been. So cool.

Exactly! It is mind-blowing to imagine what could have been. Taking cues from our new Buick SUV, with the VVT, DI, DOHC 24 valve 3.6L that makes 288 hp with a flat torque curve from ~ 2300 to 7000 rpm. Coupled with the torque amplification of the 6 (or is it 8?) speed auto trans, it makes for a smooth, firm power delivery anywhere w/in speed limit driving. My mind can't help but wander to what a state-of-the -art, 32-valve 8500+ rpm, DOHC, 6.2L with VVT and DI would have done to Corvette by now! (Do we dare even think about a V-12?:-({|=

[Blue Flame Restorations]

I'll just leave this here.

Graham, I need a pair of Phase 1 heads for motor 24. Would you happen to know of any?