Hi guys!


Got my 1969 Cutlass Supreme 350 Auto for one month now, but still don't know if it has originally the 2-Barrel or 4-Barrel carb...

I actually have a 4-barrel carb, but know that it's not the original!

Seems to me that you can distinguish a 2-bl and a 4-bl engine by the air-cleaner, presence of exhaust heat tube and some other specifics parts...

What do think?

Thanks!!


Here are some pics of my engine:

 

In 1969, all 2bbl 350s were low compression and all 4bbl 350s were high compression.
There are no other external characteristics or numbers on the engine or the car, so the only way to be reasonably certain of what kind of engine came in the car is to check the VIN-derivative number on the engine block to be sure it's the original engine, then inspect the piston crowns with a fiber optic camera and check the size of the dish and the markings (V-shaped for high compression, U-shaped for low compression).

That being said, if the intake manifold of your engine doesn't look like it's been replaced or removed, then whatever is on there is probably original, since 2- and 4-bbl carburetors require different intake manifolds.

- Eric

 

Since the compression ratio is different does anyone know what the pressure would be on a stock low compression and a high compression engine? If compression test results all exceed the low compression value then it would be a high compression engine. I am guessing that the high compression version would be in the 150-160 PSI range...anyone?

 

A high compression engine in good shape should be in the 175-185psi range in my experience (others may have had other experiences).
Low compression more in the 130-150psi range.

But wear and tear can reduce these plenty, and swapping cams can change it, too (a lot can happen in 45-50 years), so cranking compression is not a completely reliable indicator.

- Eric

 

Don't suppose you have a Protecto-Plate which might show the engine code?
Ck in the glovebox

What does it matter, anyhow?

How do you know the carb is not original?
An original '69 350 4-bbl intake would be 398663 I believe.

HELLA RARE according the recent ebay HURST OLDS MAYBE - STARING CONTROVERSY IN THE FACE guy... [not rare in real life]

 

the low compression had 250 hp high 310you should be able to notice 100hp

 

He lives in France. A lawnmower has 100hp more than a Citroën.

- Eric

 

Thanks a lot for your help!
Will check the Intake number!

Actually almost true!
We have a lot of cars with 60/70 or 80Hp here!

Even my daily driver is a 2012 115hp Ford Mondeo Break!

 

Several years ago I stayed for a while at a friend's house in Italy. She went off on holiday for a few weeks, and I drove her Dyane 6 while she was away. Not quite a 2CV, but close.
I also had a chance to drive her friend's Renault 4.

It's amazing how much fun it can be to drive a car with 30HP.

- Eric

 

If you look very, very closely at the pic of his car, you should notice that it is a Cutlass Supreme...342879....they come standard with a 4 bbl. carb. cha cha cha .

 

Ba Da BING!

Nice.

- Eric

 

Or in my sig!

THANKS a lot for your help!
Finally have my answer!!

 

True, but couldn't you also opt for a 2-bbl 350 for credit? I know you could in '70 on a CS.

 

Well, you could, but since everything else points to it being an original 4bbl car, the odd are that that's not what happened.

- Eric

 

Does the same rule-of-thumb apply to 1970 350s as well?