Pontiac Trans Am Turbo

[TonyD]

Heres something which may just interest one or two of you Yank engine enthusiasts out there.

I was trawling round a few local scrappies this afternoon looking for some bits and at Portway Motor Dismantlers on the A435 I saw the above vehicle being broken up.

The engine, gearbox (auto), interior etc was complete but the body was as rotten as a pear.

The engine looked as if it had not been run for some time, but looked genuine even down to the tippexed cylinder numbers on the distributor cap which was testament to someones efforts to get the thing going.

The Turbo sits on top of the engine driven from the left hand (off side) bank of cylinders whilst the carb sits right of centre almost on top of the nearside rocker cover.

The guy running the scrap yard told me it was a 5 litre engine and very rare as it was a " Trans Am Pace Car".

I dont know anything about this type of engine but if its a 300 or a 350 Cubic Inch "Ford" jobbie it would certainly make an interesting and unusual engine for a Cobra I would think.

If anyones interested I could be perusaded to have another look at the thing for you.

Cheers,

Tony

[wilf]

Tony - saw a Cobra with this very turbo engine in the US, it outran just about everything on the drag strip until a head gasket blew. V6, not 5 litres as I recall - smaller than that.

It just went "Wooooooosssssshhhh", and posted 10 second quarters. And kept on doing them.

Remarkable. Them Mopar boys know a thing or two. Now... anyone got a Hemi they don't want?

[TonyD]

Wilf,

The engine in the Trans Am I saw today was definitely a V8, it looked just like the normal Yank V8 but with a bloody big Turbo stuck on top of the engine, fed from the exhaust from one bank of cylinders with the carb stuck over on one side........... It even had the dissy at the front of the engine.

As the CR has probably been reduced for the Turbo you could probably just stick with the existing Turbo set up which should give mucho horses, or exchange it for a supercharger without having to re-engineer the engine too much.

To my untrained eye it looked as if they were trying to start it without the turbo connected to the intake, and with such a low compression ratio as some turbo'd engines use they'd have real problems getting the thing running.

Cheers,

Tony

[mylesdw]

The engine is almost certainly a Pontiac engine. The turbo trans-am was never really rated highly by anybody. The general opinion was that it was rather gutless compared with the 455 cu in normally aspirated motor that it replaced. I think it might have been created because the older engine would not pass emissions. Size would be 4.9 litre and running 9 psi boost it was not a dazzling performer.

[TonyD]

What would the power output be if it was a turboed 4.9 litre running on 9psi ...........without an intercooler of course........

Cheers,

Tony

[mylesdw]

Apparently the 4.9 litre turbo was VERY prone to detonation which limited its evolution and ultimate power. In a T/A which is admittedly a heavy car, no test shows better that 16.5 secs for the quarter. That's pretty slow. 210 hp is quoted.

[TonyD]

210 HP...........for a turbo 4.9 litre..............this is a pretty poor showing for an engine on a so called sports car. 42hp per litre, it just confirms all my worst thoughts about Yank boat anchors....

Cheers,

Tony

[mylesdw]

I think this one is a bit of a dog, certainly not worth using.

[gareth08]

Hi
dont know about this engine but I used to own a 5.0 Turbo Camaro IROC which used to blow away 911's with no trouble.This was also a Pace car.
Might not be same engine though and as i bought it S/H i dont know exactly what had been done to it.
Gareth

[mylesdw]

Different engine, the Camaro has a small block Chev