The Stovebolt Site Forums The Shop Area Engine Shop Carter or Rochester?

I have a '58 Apache 235 with twin Rochester B's but I'm thinking of buying two Carter YF's instead. Are they regarded as being better than Rochesters, or any difference? Thanks.

Using two of the same size carburetors designed to run an engine in a single application doesn't make good nonsense. If you think you absolutely must have one too many carburetors for some reason other than looks, at least downsize both of them. The Carter carb designed for the F-head Jeep CJ-3 engine is a good candidate if you're willing to change the spacing of the mounting studs on the intake manifold. NO carb that I know of with the wide stud spacing has a CFM rating low enough to work in a dual-carb application on a 235.

The Carter YF part number 938-SD carb for a Jeep 134 cubic inch engine would probably work well in a dual application on a 235. Then you would only have enough carburetion for 268 cubic inches- - - - -not 470!

"The ABC's of carburetion- - - - -Always Buy Carter!"
Jerry

One Carter YF3211s would be an excellent alternative to two Rochester Bs in your case. There are many reasons why the Carters are better...and those have been discussed to the point many of the folks here need oxygen. Jerry is right. You don't need 2 carburetors. Good luck!

This article from my website explains part of the comments by Jerry and Jon:

Dual single barrel carbs on 4 or 6 cylinder


Jon.

For informational purposes only.. Another..

If you like dual carbs, and I do, and you are struggling with the Rochesters, an alternative is to use the holly Weber 5200 carbs that were found on the Ford pintos. Use carbs from a 1974 pinto, that year carb has threaded inlets. Easier for fuel lines. These carbs are progressive two bbls, with small primaries and larger secondaries. Use a pair of adapters that Langdon sells at stovebolt engine co. You will need to sort out some linkage. Get some electric choke conversions from Tom, he usually has them.

These will pretty much run out of the box. I ran this set up for many years when I switched from a pair of YF carbs to the 5200s. When I rebuilt my original set up in 2014, I ordered the carbs from rock auto. Ran perfect.

Thanks for your replies. I also read the 'Carb Question' entry on the same page which was useful, and it does seem that Carters are regarded as superior to Roch B. My truck has been fitted with an Offenhauser manifold, but also the engine was given 'performance' treatment in Arizona before it was shipped to England. It doesn't seem to have been overbored but it had a Stage 4 head, new cam, con rods, valves, reground crank and many other mods. It's a good running motor but the plugs are always black despite one recon carb, new kits, lower size jets etc. I wonder if although you suggest that only one carb is necessary, that because of the uprated engine, that two carbs are still more suitable? If only one is still necessary, can the second one be blanked off with a metal plate under the base so it still fits on the manifold? I can order the Carters which are being held for me, although I'd have to modify the pipework etc. I'll look into the Weber 5200's as well, but if I go for the YF's, is only one still okay given the uprated engine?

If you use a single carburetor, you MUST replace the intake with a single carburetor intake. You CANNOT blank off one carb of a dual carb intake successfully.

As far as the Rochester versus Carter question, I prefer Carter, but I am not in England, and no offense meant, have no desire to visit unless someone builds a highway

With your uprated engine, you probably can use dual carbs successfully. But whether you use Carter or Rochester, THEY MUST BE EXACTLY THE SAME BY IDENTIFICATION NUMBER! If they are not, you are whistling in the wind.

Due to the port configuration of the 235, dual carbs are not ideal; triple carbs are ideal, but you need three smaller carbs. Or you need an IR style intake manifold. With an IR style, I would suggest three Carter type YH carbs. Forget the original Corvette units, as they are now contructed from verypricium. Instead, three from mid-1950's Dearborn marine are somewhat available, and much less pricey than the Corvette versions.

If you were to use a triple manifold with the plenum design, the Carter 938S that Jerry mentioned in an earlier post will work well.

If you plan to stay with the duals, my first choice would be a pair of Carter type W-1 574s from a Chevrolet 216; which will require modification to the carburetor footprint on the intake, as the center-to-center bolt spacing is 2 11/16 inch instead of the 2 15/16 inch of the 235 carbs. These are manual power system, and will be MUCH easier to tune than either the Carter type YF or the Rochester. If you are set on 2 Carter type YF, then a pair of the YF replacements for the 216 NOT the 235.

Should you go with a single carb, I would suggest either a Zenith type 228 from an IHC or GMC 248 engine; or if you are looking for maximum power from a single barrel, then one from a GMC 270 engine.

And much as I dearly love ( ) the Rochesters (read sarcasm), and assuming they are EXACTLY the same by tag number, I would try to find out why they are not working. Note my comment about the manual power system on the Carter W-1. One of the issues enthusiasts face when adding a big camshaft is the vacuum (which controls the power valve(s) on the Rochesters, will be different than with a stock camshaft, thus the power valve may always be open causing a very rich condition.

Also, read the thread by Jon G. on Rochester B power valve issues (stuck actuator valve, warped bodies, etc.).

As to the Pinto Webers: while others on this board seem to like these; I tried new ones 25 years ago when I could buy them new for $5.00 each!!!! Both Carter and Holley were trying to purge their inventory of these. At the time, I was unable to make one (or two) work as well as a single very worn original Rochester B that I restored. And even though I could buy them at $5.00, I completely gave up on them. There were more than a thousand available at the time.

I cannot in good conscience recommend these units due to the experience I had with them.

Jon.

Jon, I have had excellent results with the Holley Webers in the past but there is always something new to learn. You would not be inclined to walk us through the challenges you had using these carbs would you?

I'm not trying to hijack this thread, but I was about to start a new thread about a similar question. If the mods deem my question in this thread to be in bad manners or just plain wrong, please move it. Thank you, Shane

I have been doing lots of research, and have found that a Weber 38/38 is probably better suited for my 292. Have any of you guys ran this setup? The engine will basically be stock, but will get the lump kit, HEI ignition, and upgraded exhaust. Do you guys think this is a good setup, or just whistling in the wind?

Mike - too much to discuss. One problem I remember well was the 2->1 adapters. We found they needed to be a minimum of 6 inches tall, with formed, tapered runners.

If you like them, fine.

Jon.

Thanks for your replies and to Carbking for such a detailed account of the differences in carb design. I'll have to give it some thought but I'll avoid buying the YF's and give up my original idea of buying another Roch B to go with a replacement I got a few years ago. It's a complicated subject if you're not an expert, but you've given me lots of useful advice. Dingo - feel free to take over this thread, and carbking - we have some lovely motorways in the UK, in particular the M1, M6 and M25. The trouble is they're jammed with cars morning, noon and night!

Yes, but is there a bridge so I can drive across the Altantic? How about a mid-ocean service station?

Jon

Now That would be a MEGA road trip, but you'd likely need more than one mid-ocean service station.

I haven't priced Zenith 228s lately but it seems to me that would be a better option than Langdon's Pinto carbs. His setup isn't cheap either. YFs for a 216 would probably be cheaper and probably just as good.

Maybe I just got lucky years ago when I stumbled into a pair of 228s with the SAE #2 base on an Offy manifold. I put them on a 235 by slotting the carb bases and I also had to modify the gasket for the vacuum port. They have worked well for many years. No throttle lag or bog from over carburetion. The engine has Fenton headers, the 252 Crower cam discussed in another thread. Has lots of power and until recently got good mileage.

I did modify them long ago so the power valves would start to open at a lower vacuum by measuring the tension of ball point pen springs and cutting them down or stretching them (I no longer remember which). This worked just fine until we started having alcohol in all the gas and now the engine runs too lean. So I opened the main jet adjustment to compensate but the gas mileage has gone to haides. So now I'm thinking I need to go back to the original springs but they are in an envelope with a whole bunch of other springs and I don't know which were the originals. Sigh.

Anyways, the 216 sized Carters would probably do just fine too, especially with some other performance mods. I had a single YF on a 235which was a good carb but I put it on my girfriend's pickup when her Rochester cratered and I didn't get it back when we split up. That was forty years ago and I still regret it. I had a YF on a 50 Studebaker 170 champ that got 29-30 MPG on the road. In a pinch I put one of the 228s on it while I overhauled the YF and that cut the mileage almost in half. I was glad to get the YF back. I think they are really good carbs.