The Stovebolt Site Forums The Shop Area Engine Shop picking carbs

hi guys im looking for some carbs to put
on a triple offenhauser intake...
the engine is a 1955 235 with 3836848 heads

i have no idea what carbs to run so your
help is greatly appriciated

regards

To do what?

to provide a air and fuel mixture to the engine?

just kiddin guess i could elaborate¨....

the truck will be a cruiser around town and mileage is not
an issue i just want to know the usual suspects when having
triple carb setups as these are new to me... one barrel two, barrell carter holly weber????? preferably a cheap/reliable setup

GM engineers figured out that the stovebolt engine needed a single 1-barrel carb. They made millions of them that way, and they worked well. Their only mistake was thinking they could build a better carburetor than Carter. Use the right sized Carter carb, bolt it on, and drive. Putting two or three carbs on where one is all that's needed is an exercise in futility or stupidity- - - -take your choice!
Jerry

i was afraid of that answer as i heard that the three carb setup
is overkill...it just looks so darn cool!

anyone have a dual or triple setup you feel works well?
pleas share!

Use a 3-carb manifold and put blind gaskets under the end carbs. The dummies will be impressed by the cool factor, and the engine will still run right. BTW, it's nearly impossible to fit a 3-carb manifold onto a truck- - - -firewall and shift linkage interference, and some braces in the way on some models.
Jerry

well the world is full of dummies.....
thanks for the heads up on the fitment isuess...

so Hotrod who and where can I get a 3-carb manifold for a 250 ? I like your Idea of blocking off the 2 outer carb

Corvettes had 3 carbs!!!

The problem with running 2 dead pots is that the mixture distribution is worse than the stock manifold - the #3-4 cylinders runs richer than the #1-2 and 5-6. This is not an adjustment and can't be "jetted out".
This also holds true for progressive linkage with all 3 working - the center pair is too rich. The cure is surgery inside the manifold, adding a ditch across the runner entrance etc. No, there's no diagram or instructions.
If you run all 3 simultaneous, be prepared for poor response and poor mileage. Use the smallest matched carburetors you can. If you can fit Rochester Model B, the ones used on the early Gen-3 194" L6 are even smaller than the 216" Gen-2.

I totally agree about poor fuel distribution on a 3-carb manifold with two dummy carbs mounted. We used to tinker with fuel distribution on multi-carb small block V-8's by running thermistors in the header tubes on the dyno and tweaking port shapes and jetting until the exhaust port temperatures started to match up under load. For an engine that's mostly designed to win trophies at the local show n' shine, putting a couple of dummy carbs on a 3-carb manifold is a quick and dirty method of getting to and from the show without a lot of backfiring and underhood fires. It's nowhere near as good as a properly set up original fuel system.
Jerry

A 2 carb manifold with 2 smaller carbs, like the 1.5" bore Carter W-1s, or The Carter WAs like Hudson ran, is better for street use.

Read this: http://www.thecarburetorshop.com/Dual1barrelcarbs.htm

YOu'ld need to find some really small carbs to make a triple work on the street, and they don't really fit anyways, unless you want to modify the firewall.

thanks for the input fellas i went with a dual fenton and
purchased carbs from langdons.... heard nothing but good feedback
from others who has gone this route

This thread has piqued my curiosity... What is the general opinion of a single, progressive 2-bbl carb on an otherwise unmodified 216? I was thinking of the weber 32-36, in hopes of a little more economy at low cruise and a little more power wide open. Is this a good idea? Or would I need a larger 2-bbl to make it work?

My curiosity got piqued in a different way: how to have 3 carbs and maintain driveability.

I suppose one could make an elongated carb spacer from aluminum plate mounted on the stock manifold that the dummies mounted to. It could even have some fins or other details to obscure/disguise the stock intake. Any other ideas out there?

Buy an Austin-Healey 3000 MK II- - - -it's got 3 side draft SU carbs on a 3-liter inline 6 already.
Jerry

Or, maybe a Corvette intake with the Carter YH's. They come up on e-bay from time to time. If I had the money...