Gaz Hog

Is there anything on tbe vin or anywhere else that might indicate the car had a 2 or 4 barrel carb? It's a 69 delta 88 that originally had a 2 barrel. I put an aftermarket intake on it and a 4 barrel quadrajet. The issue is I want to put an original intake and air cleaner on it...the aftermarket intake won't allow for anything original, it sits too high. I want it to be as original as possible. I know they did come stock with a 4, but mine had a 2. Is there a way to tell that if I put a 4 on it that anyone could tell any different?

jaunty75

There is nothing in the VIN that would indicate this. The third character in the VIN of a '69 Oldsmobile, if an odd number, means the car has an L-6 engine. If it's an even number, the car has a V-8. That's it as far as what the VIN will tell you about the engine.

Do you have a Delta 88, Delta 88 Custom, or Delta 88 Royale? The standard engine in the base Delta 88 was the 350 V-8, 2-bbl carb, 9 to 1 compression ratio, 250 hp, regular fuel.

The base engine in the Custom and Royale was a 455 V-8, 2-bbl carb, 9 to 1 compression ratio, 310 hp, regular fuel. This engine was an option in the base Delta 88.

Optional on all three 88's were a high-compression (10.25 to 1) 455, 4-bbl carb, premium fuel, single exhaust, 365 hp or the same configuration but with dual exhaust putting out 390 hp.

If your car has a 350, then you know immediately that it had no more than a 2-bbl carb originally as that was the only way a 350 could be had from the factory for a Delta 88. Four-barrel versions of the 350 were available that year in the Vista Cruiser and Cutlass lines, but not in the Delta 88.

If your car has a 455, it could be the low (2-bbl) or high (4-bbl) carb version. What does it say on the car's gas cap? Cars requiring premium fuel often had that written on the gas cap. Below is a photo of the gas cap on my '67 Delta 88, which requires premium fuel. It's a bit worn, but you can read it. Assuming your car's gas cap is original, if it says this, then you know it originally had a high compression engine and therefore a 4-bbl carb. If it does not say this, then the car has/had the low-compression 455 and 2-bbl carb.

It may actually also say on the air cleaner if the air cleaner is original and has its original decals on it. Words like "ultra-high compression" or "premium fuel required" would indicate that the car had a 4-bbl carb.

oldcutlass

What intake and carb did you stick on it?

Gaz Hog

Wow, great info jaunty. The gas cap does not have anything on it to indicate using a higher octane. I did look at the original air cleaner top and it says oldsmobile rocket 455. I know that we did have to use higher octane due to when we turned off the car, it would continue to knock and carry on...I don't recall the name for that. What I have on it now, is a rebuilt/reman 4 barrel quadrajet that I got from someone on this site several years ago. The intake I put on was an aftermarket eddelbrock. It sits too high. I had someone on here offer to sell me an original intake manifold and air cleaner, but that was a long time ago and I don't remember who it was.

jaunty75

Doesn't necessarily mean anything unless you know for sure it's the original gas cap.

But nothing else? I don't honestly know what air cleaner decals were saying in 1969. By 1971, they just said "Rocket 350" or "Rocket 455" with no mention of high or low compression ot type of fuel required. My '67 Delta 88 does say right on the air cleaner plate "premium fuel required." There's the gas cap on my car, as I mentioned as well.

First, this is called "dieseling" in honor of the fact that the combustion is occurring with heat and compression only, without spark (as the ignition is off), which is the way a diesel engine works. Second, this doesn't necessarily mean anything as dieseling can occur for other reasons. But it could indicate that your engine requires premium.

MDchanic

Not really. A high compression engine running regular will ping, but it shouldn't run on.

It just means your combustion chambers are full of carbon.


And the high compression engine should have come with an orange air cleaner, while the low compression engine came with a black air cleaner.

The air cleaners for the 2bbl and 4bbl are completely different and are not interchangeable.

- Eric

Gaz Hog

So Jaunty, with what you have said and what I have not seen, I have a base Delta 88 with the optional 455 2 barrel. There is nothing that says custom or royale...so with the information you provided, someone who is an olds aficionado would likely know that the 4 barrel was not stock on my particular vehicle, correct? And according to what Eric said, mine is a low compression.

MDchanic

LOTS of base Deltas were ordered with 4bbls, so that's not really an issue.

We can speculate indefinitely, but if you want to know for sure what your compression is, look through the spark plug holes at the notches at the front edges of the piston crowns with a bore scope - HC is a V-notch, Low compression is a U-notch, as illustrated in the chassis Service Manual.

- Eric

Gaz Hog

So regardless of high compression or low compression (I dont have a bore scope at the moment) they could still have come with a 4 barrel? A high compression with a 4b simply had more pony power vs a low compression 4b right? Grandpa was telling me that this car with a 2b just wasn't meant to have the 4b and put too much stress behind it. Am I safe to assume their is no basis behind this statement? Thanks so much for the info so far everyone; very insightful.

MDchanic

For the 1969 Delta, all 2bbl engine choices were low compression, and all 4bbl engine choices were high compression, so the type of pistons will tell you what type of carburetor was on it originally.

Look around and see whether anyone you know has one of those scopes - many of them are less than $100 now.



Yes.


Yes.

- Eric

Gaz Hog

And so my next question, naturally, is who has an original 4 barrel intake and air cleaner to sell for 69 delta 88 with a 455.

MDchanic

With the number of people who pull off the original manifolds to install aftermarket units, it shouldn't be hard to find one.
They're not worth much, as they're extremely heavy and therefore impossible to ship for a sane price - most people will give them away if you'll come get them.

The air cleaners can be a bit tougher, as, if I recall, they were also used on some 455 Cutlii.

- Eric