Is this a v6 Turbo ZR-1 Prototype Engine? Friend purchased it (pics) ---

[alwayscode390]

http://farm4.static.flickr.com/3433/3399779330_0612a056e7_b.jpg
http://farm4.static.flickr.com/3548/3363696880_eef01e38c6_o.jpg
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http://farm4.static.flickr.com/3603/3363699352_796481613f_o.jpg

He bought it not knowing what it was, but eventually figured out it may have been one of the test engines for the 4.3 Turbo v6 idea GM had for the ZR-1. He was going to stuff it into another car, but it just sits in his garage for the past 3 years.

Figured you guys would be interested in it ... so I snatched up all the pics he sent me awhile back. I just remembered it lastnight :) ---

[alwayscode390]

http://farm4.static.flickr.com/3577/3363716080_09e0b69b22_o.jpg
http://farm4.static.flickr.com/3575/3363716350_237392b216_o.jpg
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http://farm4.static.flickr.com/3437/3362897885_6b7eb6939b_o.jpg

[alwayscode390]

http://farm4.static.flickr.com/3547/3362897835_2d96d757f6_o.jpg
http://farm4.static.flickr.com/3470/3366303890_4bc1247a58_o.jpg
Some marking on the turbo.
http://farm4.static.flickr.com/3419/3366303852_1e5d40de77_o.jpg
Some markings on the IC.
http://farm4.static.flickr.com/3627/3365480397_47bfd26b3b_o.jpg
http://farm4.static.flickr.com/3601/3387537095_f3ddd18ae7_o.jpg

[alwayscode390]

http://farm4.static.flickr.com/3627/3389883491_194e3cf269.jpg

These might give you guys some ideas for making some log manifolds.
http://farm4.static.flickr.com/3585/3390698890_3f3cc61cb3_b.jpg
http://farm4.static.flickr.com/3603/3390702066_9896eb6e55_b.jpg

I found 2 oil pressure units. One for a gauge & one for an idiot light?
http://farm4.static.flickr.com/3580/3390700876_dd2c2a2952_b.jpg
http://farm4.static.flickr.com/3638/3389886333_ffb06b2a34_b.jpg

[alwayscode390]

http://farm4.static.flickr.com/3464/3398540955_74931894f1_b.jpg

http://farm4.static.flickr.com/3445/3399349950_083836d4cf_b.jpg

[GOLDCYLON]

Well the top plenum is very L-98ish however it looks like a cross between a Buick. GC

[alwayscode390]

He contacted the SVI people , they gave him the first pic I posted. They verified that they were building these engines for a Corvette prototype. The turbo lag and the engine shaking of the unbalanced 4.3 was too much hassle for GM to approve the design. Im not sure if it was ZR-1 specific though ... but the year "1987" seems feasible.

He originally bought it thinking it was a SYCLONE/TYPHOON prototype engine , but its too big to fit in the s15 body ---

[GOLDCYLON]

Im thinking this might have been a bad marriage between GM and the Buick Grand National Program or Turbo Regal V6 Arena. Turbo is in the right spot however the intake is way off hence the marraige comment (More like a shotgun wedding here)

Time period is also about right. Who knows what evil lurks in the hearts of prototype engineers.

[Fully Vetted]

It may have been for a Corvette prototype but not for a ZR-1. There was no indication in The Heart of The Beast that there was ever a consideration for a T-V6 in the ZR-1 that I remember.

[alwayscode390]

I thought I read somewhere that the turbo v6 was an option ... when they were shooting for 400hp ... but people really took it hard that it wasn't a v8 for the "top of the line" Corvette (zr-1) , so that's another reason it was squashed ? ---

[ZZZZZR1]

Looks like a camaro engine block? 1987 fits in with a potential turbo upgrade??

Great find!!!!

:cheers:

David

[alwayscode390]

I did hear about a 3rd gen Camaro turbo 6 concept also ---

[Hog]

Cool looking setup for sure. I wonder if the V6 +turbo + I/C + plumbing would be close to the weight of an L98 or the ehavier LT5?

Could V8 manifolds be swapped out to be used in a V8 application?

It would be interesting to get a readout of that PROM.

peace
Hog

[scottfab]

The flange on the headers is what 0.750 in ? wow

[Schrade]

I did hear about a 3rd gen Camaro turbo 6 concept also ---

And a C3 turbo V-6...

[Hib Halverson]

A turbocharged V6 was never, ever considered as power for the ZR-1.

Way back in late 85, when what would become the ZR-1 was still in the early design stage, GM briefly considered a DOHC cylinder head conversion for the existing Gen 1 SBV8, but that's the only other engine configuration which was considered.

That said, keep in mind that before the idea of a Corvette worthy of the term "world-class sports car" (ie: more than just a "bigger" engine but a complete package of powertrain, chassis and brakes), in late-84/early-85, GM was looking for an engine capable of more more than 230-hp, a twin-turbo V6 was tested and quickly rejected.

[LGAFF]

SVI did a prototype TT Corvette(v8) in 85 or 86. GM used this prototype to work with Callaway in putting the TT into production.

[LGAFF]

http://i134.photobucket.com/albums/q115/lgaff/svi-tt_zpscdee9d56.jpg

[grahambehan]

A turbocharged V6 was never, ever considered as power for the ZR-1.

Way back in 85, when what would become the ZR-1 was still in the early design stage, GM briefly considered a DOHC cylinder head conversion for the existing Gen 1 SBV8, but that's the only other engine configuration which was considered.

The Original contract negociations with Lotus was for just this.:handshak:

Graham.

[LGAFF]

Before landing on the LT-5 vs a TT setup, GM did build a series of TT cars....Motor trend noted that they ran a test with a Lambo running at 120, as it passed one of the TT prototypes(sitting still) ...Jim Engles punched it....at the end of the mile the TT vette has passed the lambo at 180+....

[XfireZ51]

Before landing on the LT-5 vs a TT setup, GM did build a series of TT cars....Motor trend noted that they ran a test with a Lambo running at 120, as it passed one of the TT prototypes(sitting still) ...Jim Engles punched it....at the end of the mile the TT vette has passed the lambo at 180+....

"Jingles" was the go to guy for doing some crazy sh*t. He's the one that did the validation on 1/4 mile times. BTW, that included real power shifting. Never let up.

[LGAFF]

Interesting the ConsumerGuide published in 12/88 mentioned the turbo 6 was a test engine for the ZR-1; as stated too rough



He contacted the SVI people , they gave him the first pic I posted. They verified that they were building these engines for a Corvette prototype. The turbo lag and the engine shaking of the unbalanced 4.3 was too much hassle for GM to approve the design. Im not sure if it was ZR-1 specific though ... but the year "1987" seems feasible.

He originally bought it thinking it was a SYCLONE/TYPHOON prototype engine , but its too big to fit in the s15 body ---

[alwayscode390]

;) ---

[scottfab]

Interesting the ConsumerGuide published in 12/88 mentioned the turbo 6 was a test engine for the ZR-1; as stated too rough

That must mean it WAS considered for the ZR-1.

[1989ZR1#74]

That must mean it WAS considered for the ZR-1.


I am pretty sure the ZR-1 was always LT5 powered from day 1. This may or may not have been a "study" for the Corvette but not a ZR-1. The ZR-1 was an "option and Marketing group" that group included the LT-5 like the Z28 camaro's had 302s. You couldn't get a Z28 with a 396.

If it is a Corvette powertrain it could be related to the program that build EX5273 in 1988. EX5273 was a twin turbo V8 concept study. It sold at BJ2009 Palm Beach:

http://www.barrett-jackson.com/application/onlinesubmission/lotdetails.aspx?ln=57.1

http://www.syreal.com/1988_turbo.jpg

[1989ZR1#74]

OK I went digging. Per Dave MCcLellan's "Corvette fron the Inside" page 195:

"V-6S AND TWIN TURBOS
To his credit, Lloyd kept the pressure on the engine guys. Their first
response was a turbocharged 90-degree V-6 for the Corvette. They reasoned
that the smaller displacement was needed, both for fuel economy and to
accommodate the turbochargers and auxiliary plumbing. But we rejected
the V-6 engine, and so did the car. The engine caused problems in the driveline
and rear suspension and made the car buzz and the mirrors shake. This
unbalanced V-6 engine configuration was totally unacceptable when
mounted in the Corvette, which had never been designed for such an
engine. So, the engine guys finally got the V-6 out of their system, and we
settled down to work with them to package a twin turbo V-8."

http://www.syreal.com/Mclellan_turbo_page_sm.jpg



If that is the engine that is a very rare piece of Corvette history. Thanks for posting it.

[1989ZR1#74]

I will go one step further and say the name "ZR-1" didn't really exist until the 1988 time frame. Up until that point the LT5 moniker ruled the day. If you look at the 1988 and earlier build sheets you see LT5 hand written on them and King of Hill noted but no ZR-1 anywhere. ZR-1 really came to fame when Chevrolet denied the use of the LT-5 badging due to GM's own new restrictions on noting engine's badging on the outside of the vehicle. Hmmm does that make Queenie just another Corvette? I will let Tyler decide.

[LGAFF]

This is the prototype Corvette turbo 6....Callaway just posted a pic of it in the car on Facebook

[icarus-54]

Saw one a many years ago at Watkins Glen,it was in a prototype road racer.I think it was around 90-91.It caught my eye because I had just bought my first gmc syclone new.

[Z51JEFF]

That motor looks like a Big Block with 2 cylinders lopped off.

[icarus-54]

Thats why it caught my eye,it was the first 4.3 I saw with splayed valve heads.I talked to the owner,he said that they changed it from even fire to odd fire by changing the crank,ignition and electronics.When I heard it go by it was turning some awesome rpm.Way more than an even fire is capable of.If you think an even fire 4.3 runs ruff,an odd fire idles like a washer machine with one leg missing.

[Tripler]

Perhaps a prototype mid engine for a mid engine corvette ???

[Hib Halverson]

I know this is an ages old thread and I know I've posted to it before but I just noted a small detail in those images.

There is a part dated "MY87".

That rules that engine out as having any association with any Corvette development program that is pre-ZR-1. By 1987 the ZR-1 development was way, way past considering any other engine.

[LGAFF]

Reeves Callaway would know what engine this is...Callaway had a pic on their facebook page

https://www.facebook.com/25478154717/photos/pcb.10152146937714718/10152146934864718/?type=1&theater

[LGAFF]

The story is posted there also...

[LGAFF]

Looks like the V6 TTs were abandoned after they did not meet the cut on HP...same output of NA V8s

[J-Bonez]

It maybe the engine they put in the transam....v-6 turbo i believe it was late 80's

[BigIke]

So cool! Looks like they married a big block head to the 4.3 v6! That's awesome

[Hib Halverson]

So cool! Looks like they married a big block head to the 4.3 v6! That's awesome

It's not a BBC head "married" to the 4.3.

The splay-valve V6-90 head was a clean-sheet-of-paper, racing part, released back in the '88-'90 period for the V6-90, which, back then, was popular in a number of racing series. While it mimicked the Big-Block's splay-valve layout, it departed from the BBC design in that the valve configuration was equally-spaced (E-I-E-I-E-I) whereas the BBC (and the Gen 1-2 SBC) were E-I-I-E-E-I-I-E and the production 4.3 was (E-I-E-I-I-E).

I noted that the image of the top of the head with the rocker cover off also showed a CN with an "X" in it which means the part was "experimental". That's a clue that the heads were a development piece at the time the images of the engine in a C4 were taken. Later examples of that head, i.e.: parts off production tooling, have only the PN and not the CN with the "X".

There were several versions of that head, apparently, because I've seen them with PN 10134384, as well as, PN 14044841 shown in the imagery in this thread.

[mgbrv8]

Cool stuff Nathan

Dave

[alwayscode390]

J-Bonez the engine in the 89 TTA Trans Am was just the Turbo Buick 3.8 lc2 engine but with pontiac heads. Could have been planned for it , but I would expect Pontiac Power Valve covers? :) ---

[Hib Halverson]

The engine in the Turbo TransAms from 1989, were Buick 3.8 turbos. No "Pontiac heads". The build was so small, Pontiac would have never done a specific head. Not only would the head have cost a fortune but Pontiac would also have had to certify the engine with the EPA. It made much more sense to use the engine right from Buick.

Either way, that was a bad-*ssed car for 1989. I remember road testing a couple of them for magazines back then.

[alwayscode390]

Sorry but you are wrong Hib, I used to own a TTA , #5 to be exact.

They require different headers than the Buicks.

Here is a very informative post , look down a couple posts :

http://www.turbobuick.com/forums/threads/tta-cylinder-heads-chamber-volume-exh-ports.391515/

They didn't make a "specific head" , they used already commercially available heads off the "3800 traverse v6" engine already in production that actually outperformed stock lc2 Buick heads!

" It was fitted with cylinder heads from the existing traverse V-6 3800 Series I heads, PN: 25536702, which yielded superior combustion chamber design & exhaust flow of the GN/GNX design. It allowed room for the downpipe to fit, and also gave more clearance around the strut towers & A/C box on the firewall. " ---

[Hib Halverson]

I envy you owning one of those cars. In 1989, the Turbo TransAm was the quickest (and may have, also, been the fastest) car GM sold. They also handled pretty well because of less weight on the front end.

Again, the heads you're talking about are not "Pontiac Heads".

They were based on the Buick 3.8L design. Buick was responsible for the 3.8 and its offspring, the 3800 Series 1, not Pontiac...though the Pontiac folks brokered an excellent deal to use that engine in the Anniversary TTA.

When GM Powertrain was created in 1991, it took what Buick had done cylinder head wise and developed the 3800 Series II and, later, the 3800 Series III, both of which used that revised head design.

The head may required different headers because the exhaust port flange was changed.

That head was eventually used on 3800 S1, II and III engines in Chevrolets, Pontiacs, Oldsmobiles, Buicks and Holdens. The final supercharged version (L32) used a "revised-revised" version of the head.

Production of 3800s ended in August of 2008. It was one of GM's better engines and was on Ward's 10 Best Engines list.

I have the same head, somewhat modified, on the 3800SII (L36) in my '01 Camaro. It's a pretty darn good head for an engine like that but...too bad they never did one in aluminum.

[alwayscode390]

When u said they took the engine right from Buick you made it seem that it was a 100% straight engine transplant and it was not. In that link i posted it tells all the differences. Thanks for the technical information ---

[Hib Halverson]

I know this is an old thread, but I'm doing an article for Corvette Magazine about some of the development vehicles which led up to the ZR-1.

The engine in the OP's photos is a 4.3-L V6-90 with splayed-valve heads and a single turbo which was the first engine configuratioan tested for what was known inside GM back in '83 as the "400 horsepower package" an idea which predates the LT5 development by a couple of years.

As Dave McLellan points out in his book, the V6 single-turbo was quickly rejected because: 1) it made not much more power than L98 which was coming for 1985 and 2) the noise and vibration characteristics of a C4 with a 4.3L V6 were awful.

The next step was a V8 twin turbo, of which 14.5* were built. That idea never went to production either because Lloyd Ruess believed it would be rejected as low-tech once it got to market. The technology developed during the factory TT program was given to Reeves Callaway and GM moved on to DOHC heads for the SBV8 and, subsequently, to the LT5.

*I say "14.5" because 14 coupes were built. Then, right at the end of the program, the powertrain from the last coupe was removed and transplanted into a convertible. Of the 14 engines built, 13 were "standard" 440-hp versions, but the last was a 560-hp version with an induction system having larger runners, a bigger plenum and 20-psi boost.

Digging up some of this old stuff is quite educational.