2 or 3 Carbs. on a 331 Caddy?? Opinions Please

I am building a Model A Tudor on Deuce rails with a 331 Caddy. The engine will be kind of bare bones and stock looking on the outside with little or no chrome (but hopped up on the inside). I want a '49 or early 50's look for the car.

I was thinking of just running a dual carb. intake for simplicity and think it would look real good for the style I am keeping with. What's the preferred setup? 2 or 3 carbs?

I was thinking of going with the Offenhauser dual intake and Stromberg's.

Opinions please...2 or 3 carbs?


Thanks in advance!!!

 

you know everyone wants you to run 6 carbs. two will be cool but, three makes better presentation on large V8

 

When people talk 2x2 on early GM overhead 8s, most think of all the Edmunds that were sold, and those were very early.

So, it seems like most of us see 2x2 as earlier than trips, but it's probably not true.

I have had such good luck with trips for decades, but all were Rochesters. I like the looks of 2x2 and 3x2, so it's a toss up for me, but i'd bet the 3x2 wins on MPG if set up as progressive like most all are.

 

I vote for 3 Rochesters. Back in the late fifties, a friend of mine had a recently built 265 in a '55 Chevy with the vaunted "Duntov" cam. He was lucky enough to find a 3 duece manifold with 3 '94's on it. We put it on, and had all kinds of trouble with it, plus, it didn't seem to have very much power. When we looked closely at the manifold, we saw that the carb bases were big enough for 4 bolt carbs, even though it was drilled for 3 bolts. We drilled the two additional holes in each pad and installed 3 Rochesters from the junk yard the the difference was like night and day. It ran good from the start and seemed to have a lot more power. (We had pulled the chokes from the end carbs and just cleaned them up). We were running a progressive linkage, and he ended up very happy with it. The next summer we found a 6 card manifold with 6 '97's. That one lasted about a week before the "trips" went back on.

If a 265 Chevy could take 3 small base Rochesters, I think and Cadillac would be undercarburetored with 2, especially if the were older, smaller carburetors like Carters or Bendixes.

 

In a 34' pickup was running a 57' 365" Caddy that was bone stock utilizing a Edelbrock 4 duece setup with 94's. It got 20 mpg with a 4 spd. Muncie & 3.08 gear. I'd say carb it up!

 

Beauty is in the eyes of the beholder. 2, 3, 6, ??? your choice.

Performance is a different matter, and a properly selected and tuned set of dual quads will beat the other choices in power, driveability, AND economy.

Timeframe - Cadillac used dual quads as a factory option in 1955. Guess that is mid '50s rather than early 50's.

Most of the guys racing Allards with the Cad engine replaced the Detroit Racing 2 x 2 set-up with dual quads when dual quads were first available.

Jon.

 

I'm a cheap bastard and Cad El Dorado's had dual quads 55-57 and tri-power 58-60 plenty of cheap ones out there. I paid $340 with the truck attached and running

 

The more the merrier!!!

 

I ran 3 dueces on the 331 I had a long time ago. I liked it once I got it dialed in. I am more of a 2x4 man anymore, I think either would look correct.

Ok let me fix my own mistake here. I didn't notice it was a 40/50 look. No 2x4 setup yet. Maybe a 2x2 on a home made intake.

 

This is a Stude but most people think it's a Caddy. I like the 2 deuce setup. 3 deuces are done so often on Chevy's that I personally think that they are over done. 2 deuces will stand out in a sea of tripples. IMHO I'm betting you didn't select a Caddy engine to blend into the crowd.

I have 3 deuces on my FE Ford engine but it is a 60s style build. 2 deuces were long gone by then.

 

I have a 331 that I want to use in a early 50's style build and want to go with a 2x2 set-up. To me it is the best looking set-up.

Will probably use the Offenhauser repop from Vintagespeed.com. Pretty good price at $349. I have seen an actual piece and they look nice. Can't speak to the fit, tough.

 

Hello, here is a 2x2 setup with rebuilt 97s..Now, this would look great on the Caddy..OH, it is for sale..
Duane.

 

You guys rule! Thanks. I was really mainly thinking dual carbs because of the early look I'm going for. A dual carb setup best fits that I think. I want a '49/'50 look with pretty much no chrome on the engine.
I just don't want to sacrifice ass hauling ability. The engine will likely be kinda mild with a little over bore, cam and dual or tri intake.
I don't know much about these Caddy motors to gauge the hot set up.


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I would personally go with a staggered 4x2 on that cadillac mill but if your going for the 50's look i would still go with 3

 

Benno; Edmunds made a VERY early 2x4 for Olds 49-53, and he was more into Cadillac OHV8's in those years, so he may have made a very early Cad 2x4.

One hamber put up a pic of a "Cadillac Edmunds sales brochure" that must have been from when the OHV8 came out. It showed that you could bring your Caddy into his shop for a new motor with all the Edmunds stuff on it. I don't recall if it showed what intake it had.

Anyways, here are my 2 Olds engines which are the same physical size as Cads. One is factory iron 3x2 with Rochesters, and the other is Edmunds 2x2.

 

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What's all the ebay jargin??


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When making a selection such as this, it is sometimes useful to look at the original carb, and then the carbs used for replacement.

The original Carter carb used by Cadillac has a 1 3/16 inch venturi. A Stromberg "97" has a 15/16 inch venturi.

Generally speaking (this will depend on the design of the intake) one should derate the flow of multiple carburetors by 20~30 percent. Example: (2) 200 CFM carbs on a dual intake should flow from 280~320 CFM, depending on the design of the intake.

In the above, poor intake design (use 30 percent) 2 times 200 times 0.7 = 280.
Or good design (use 20 percent) 2 times 200 times 0.8 - 320 CFM

The same rule of thumb can be used if one does not have published (or guesstimated) CFM ratings by comparing venturii area.

Doing some math (remember, math IS your friend for good performance):

The original Carter would have 2.22 square inches venturi area (1 carburetor).

Using an average derate figure of 25 percent:

(2) Stromberg 97's would have an effective venturi area of 2.20 square inches (slightly SMALLER than the original carb!).

(2) Stromberg 48's would have an effective venturi area of 2.66 square inches.

(2) Original Carter carbs would have an effective venturi area of 3.33 square inches.

We have set up several of these setups using the original Carters; but no reason why other carbs cannot be used (the Stromberg 48's should be useful, as well as many others). Just important to do one's homework before opening the wallet.

Jon.

 

JMO, but when it comes to the cool factor with carbs "more is always better". I would go with the 3x2!

 

Hey.. for my $$$, 2- two barrels..........really looks nice on the 331 Caddy. I had one on my old Buick/Caddy engine and it looked cool as hell.
You did not say if you were running the Hydro. Any of the old manifolds created a problem with the kick down on the trans.
One of the first manifolds for public market, 2 - twos by Detroit Engineering solved the problem by adding a stock throttle shaft in the center of the manifold which lined up the trans rod and the carb gas pedel rod in the stock position.
Then the 2 stock 2 barrel carbs were put on backwards, then the two were connected on the wrong side to work in unison.
This made selling the set up to people who owned expensive Caddys in the early 50's easy "bolt on" to buy into the "hot set up" for more HP.
If you ever see one of those manifolds your lucky, ther very rare.
Two two's dude!!
Barresse'

 

i like the look of the 2 duece set up..like tommy I think it stands out more and is a definite time stamp to the build.

tok

 

I run 3x2 on my 331 with a 4 speed, it would probably run better with the 2x2 though.
That Edmunds set up looks nice!

 

Yes, there were/are Edmunds 2x4s for Cads. I have 2 Edmunds 2x4s for Caddys. Been running 1 of them for 40 years plus or minus.

 

Definately 2 carbs. Two 4 barrels!

 

That's some good info from Barry and Davey...

OK, stop with all the cool early Caddy stuff I feel left out

I can't help but notice that the Cad exhaust manifolds look very user friendly around steering gear and tight frames, and if I remember correctly, they have the right hand starter location and front side engine mounts, too

 

2 carbs and you want the bent over carbs like they used on Olds and Stude.

I ran 3 carbs on my old 331. But that was because I had the setup, if I was looking for a setup today I would be after a twin pot setup.

A 2x4 won't get him his 49 or 50 look. I like the setup but it won't net 49 or 50.

 

Three

 

seabeemc, did you make those headers or buy them????

 

F&J Yes on front mts and RH starter. The ex manifolds on mine are "center dump" from the RH side also, just ground/trimmed off the gen mt and cleaned up the manifolds and used them on both sides. The ones that seabeemc uses look like the ones Squeak Bell at Kewi Konnection (when he owned it) used to make. Good looking set. wish they were still available.