So I posted a while ago about putting dual carbs on my 235 and you guys were all very helpfull. I went to our oldest and most known car parts store in Portland Oregon called "Old Car Parts" I told them what I wanted to do and they said "no you don't it won't work!" The owner said, just put in a 261, dual exaust, and thow away that powerglide. Thats not the answer I was looking for..My car runs great I just want to do a little upgrade. They said with dual carbs it will feed it too much fuel and it wont run. Now I know that that people do that all the time so it has to work. I'm not sure what to do now.... Anyway input would be greatly appreciated.
Guys have been putting 2 carbs on Chevy six cylinder engines since before you could even buy one as a 235. Heck, Hudson sold it's six with a factory option for dual carbs. For that matter, Chevy did too, in Corvettes. My suggestion is go someplace that wants your business - Speedway has 2-carb intakes in their catalog and won't try to sell you a 261 instead. The guy is right that the Powerglide is not the best transmission to run, but if it works there's no reason to change it.
Yea I've been on speedway and I'm probably gonna order this: http://www.speedwaymotors.com/p/690...-Intake-Manifolds.html?itemNo=chevy%20235 Then from Langdon's stove bolt I'll probably get 2 of the Carter Webers http://www.stoveboltengineco.com/acartpro/product.asp?productid=97 You think that would work?
Why not ask Tom Langdon to help you set that up?I think he'd have everything you'd need in one package.I've found him helpful.Patricks in Mesa Arizona is another place that knows their buisness.
Best dual carb setup for a 235 are 2x 216 carbs like the Carter W-1 574s from 1948. 2x 235 carbs are too much for a street 235 under 3000 rpm. The engine will hesitate under acceleration and always run too rich. A 216 2x1 offenhauser can easily be adapted to the 235 head ports with adapter alignment rings from Larrowe's or just have the ports bored for the standard alignment rings at your local machine shop - same $30 cost. Now all you need are fenton headers with a heatplate on the intake for exhaust heat. The Carter carbs are easy to find, restored and rebuilt. Got them on my daily 235 and never have to adjust anything or worry about them. Gives about 20 mpg on the freeways with 3.55 rear and stock driveline. On a 1954 and later 235, a dual carb and split exhaust setup will take advantage of the better cams of the later 235s. Better mileage and power especially above 2000 rpm. If you stay mostly under 2000 rpm, keep the single intake/exhaust, but find a Carter YF with manual choke, matching the year of your engine.
If this is true then why are there so many dual and tripple setups with the 235 stud spacing? Do you take the 216 carb and put it on the 235 base? I'm having major problems with my 2 Rochester setup. It was running great but now it won't run at all. I'm running 2 235 Rochesters on a Fneton 2 pot intake with Fenton cast headers. The engine has a Howard 254 duration cam and is 30 over standard bore. I'm in the prosess of rebuilding the carbs. If I'm going to need to go another route then I don't want to go any farther with that. I'm really not wanting to buy a new intake and IF I want to use the Fenton intake then the Carters are out of the question. They have the 216 stud spacing. What is my next step?
Any of the old Chevy six speed manuals will tell you that dual carbs are the single most advantageous modification you can make to your engine. As to the difficulty of running dual Rochester B model carbs, Pat Smith found the secret of getting them to run right in a dual application, and the Inliners website should have his article on it available.
I have been running two Carter-Webers from Tom Langdon on an Edmunds water heated manifold with Fenton headers on my 235 for about 15 years. I drive this daily and it has worked flawlessly. You should have someone well versed in carburated engines check the jetting and recurve the distributer. I see you are in Portland so if want to take a look at this set up, drop me a note.
235 dual and triple intakes are great for 235/261 race engines and cams with high duration and lift. 2x 216 carbs and headers are perfect for a 235/261 up to 3500-4000rpm with stock or mild cam. I had a pair of 235 RochBs and later a pair of 235 Carter YFs for a few years on my late 235, before I realized I had too much carb for my engine which never goes above 3500rpm. Too much unburnt gas is wasted, when you put twice or triple the carb on an otherwise unmodified engine that runs efficient and lean with just one. With multiple carbs on a log manifold, the flow for each carb drops and a smaller carb still gets enough air flow to give ideal air/fuel mix. Too large carbs and the mix is too rich. Re-jetting alone doesn't help. Gotta bring the venturi size down first.
If you want to keep the 235 intake, a pair of early 235 Carter YFs would be better than the Rochester B. On my 235, I used to have a pair of 235 Carter YF 3211s auto-choke, which I eventually converted to manual choke. I tried to go down one size on the main jet, but got hesitation when punching the throttle, so I went back to stock jetting. The other thing to remember with YFs is to not let the carb bowl go dry, if the engine is not run for a while. The neoprene on the power valve needs to stay submerged with our modern gas, or it will harden and crack. It was a good setup, but after I switched to the 216 carbs and intake, I never looked back.
Ok so I looked around and picked up a pair of Carter WA 1 carbs. One 413S and one 414S (they are the same carbs but the 414S is an automatic choke) Both NOS and new in the box with the service manuals!! I'm going to trade these out with the Rochesters. Not a YF but they seem to be a good carb from the same era. Still learning about them. I found some info on them. The original service manuals say that they were for 100 - 250 CID engines. Seems they would work great from everything I am reading. Plus they have the 235 manifold stud spacing.
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