Hi all, My 235 has a Rochester B that leaks and floods and is difficult to re-start hot. I've rebuilt it with new gaskets, and set the floats to spec... all of that. I've heard that a Carter YF might be a good replacement, but that it will leak, too, when shut down. Is there a carb available that will work on my 235 that won't leak, and will easily start up and run? I don't care about originality, etc.. Just making a driver. any suggestions? thanks,
Carby Fun (or not) Well ; If the carby is properly set up and the engine isn't overheating , it shouldn't leak per se , just seep a bit around the joint , most 1940's tech carbys do . The correct starting drill has much to do with easy starting , hot or cold , if you're moving the gas pedal whilst the starter is cranking the engine , you're doing it wrong . Cartet YF's do not leak and they only seep a tiny bit plus better power and economy etc. so if you can afford one , do that . Once you have a Rochester Series 'B' adjusted to where you like it , it is , in extreme cases (or damaged air horns) permissable to coat both sides of the air horn gasket with Permatex # 1-H sealant and then assemble whilst tacky and allow to dry overnight before adding fuel , this will stop the leaks & seeps . HOWEVER this is a more or less permanent repair that is difficult to undo so you might well destroy the carby taking it apart next year after you ignored my specific fuel filter advice . Consider very carefully before glueing a carby to-gether as you'll need to drain it then soak it in a bucket of alcohol for a day before it'll ever come apart again without damage . You have been warned , this is extreme advice . Most of the time I find that learning the proper carby adjustment and tune up along with rigerously following a specific starting drill , obviates the need for these measures but it takes patience and time . I hope this helped . Avoid plopping on a modern two barrel carby (usually Holly) because it cannot properly meter the fuel and so creates running problems whilst wearing the engine out rapidly from over fueling the center port .
Thanks Nate, good advice. I was going to look for a Holly, but now I guess I should search for a YF Carter. None on this forum for sale right now. Maybe Ebay? I've just about given up on the rochester B for now.
I found a Carter # YF6429S 2264 for a good price, and I could get a rebuild kit, too. It has an automatic choke. Is that a good thing? will it work for my 235? Is there information available about which model numbers will work best for my engine? Or are all YF's the same?
Carter YF Carbys Make sure before you buy ~ I no longer remember the correct Carter # but it is stamped on every single piece of the carby . NEVER ask the seller ' will this fit a 235 Chevy ? ' as the answer will always be " ! YES ! " regardless of what it actually fits . The correct P/N is in some older posts , I don't know how to search them though .
Avoid plopping on a modern two barrel carby (usually Holly) because it cannot properly meter the fuel and so creates running problems whilst wearing the engine out rapidly from over fueling the center port -Nate__________ Did you say avoid plopping on a modern two barrel carby (usually a holly)? How bout plopping on two of them instead! .......Big Tim
Still Confused Most of the day looking on line for carbs. Found yf's and Rochester B's. Must make some kind of decision soon. Buy a YF? Buy a rebuilt B? Have my B rebuilt again? Get parts and rebuild B myself? taking opinion votes now...
Free advise! If you've been a lurker for any time at all, you'll know that I give it out like Nate's AD parts tangerine tree! If your rotten-chester carby does not leak like a seive, rebuild it. NAPA sells a rebuild kit for cheap with good instructions. Make sure to tell them as much info as you can about your existing carb. It's a lot cheaper than spending $150 to $200 for a rebuilt one that is going to do the same thing down the road. They all leak, that's the nature of the beast. The solution is having one that weeps slightly after running for a long time! Just my 3 cents (adjusted for inflation!)
Multiple Carbys Yes , more than one carby allows to more efficient metering of the fuel but two big carbys is only going to work out well if the engine has been modified to flow better like yours has . Just plopping on one big central carby will make the two middle cylinders run to rich as these are three port engines and you cannot change the laws of physics . For the same reason , adding two (or three ! stock carbys wakes an otherwise bone stock engine right up .
What To Do ? I'd suggest just taking the Air Horn off your current carby , don't dismount the entire carby , just undo the four screws and ever so carefully lift off the Air Horn and re-check the float height ~ my bet is : it's too high as it's very easy to brush the float against the gasket when you're assembling it and upset the float height , raising it so it'll weep more . I find most 'B' Series carbys have this fault . Do this first and see how much fuel is in the bowl when you remove the air horn ~ if it's within 1/4" of the upper edge of the float bowl , either the float is set too high or there's a tiny bit of crud on the float valve's needle , this allows fuel to keep dribbling in even after the float has raised up and it also causes hard starting cold or hot . Also check to see if the floats are leaking and maybe have some fuel sloshing 'round inside them ~ if your floats are dented or have fuel inside , they're junk ~ NAPA sells brandy new ones affordably . Both floats must also be parallel , adjust by bending then re-check the float's height and drop . So , to answer your question directly , YOU must be the On Site detective and diagnose the problem as just changing carbys willy-nilly won't be any gaurantee of it being done right . Give it a go and let us know what turns up .
Even more confusion I'd call Tom Langdon and see about putting a Holly (or even better, two) on it. Have to respectfully disagree with Nate on this one. I don't believe it is over carbed, it is smooth, trouble free, leakless, and the best thing I've ever done to mine. Bob
Hey Nate I was just messing with ya, well cause I can... You're right though, my engine has been modified to handle the 2 holly 350's and I designed the manifold with equalizer tubes and baffles to help atomize the fuel and direct it to where it needs to go. This particular engine is 1 of 2 that were built identical and has ran with very few problems for many years. They seem to react well to the right modifications and proper maintenance and in case you were wondering, it runs like a STRIPED ASS APE!.....Big Tim
Dual Holly's So then ; You put two two barrel Holly 350 CFM carbys on an otherwise unmodified 235 and it runs smoothly and has no off idle bogs or other issues ? . that's great , please send pix as I need to learn a new thing here .
No Worries Tim ! I know this . I bet you're old enough to remember the " SSA " brand of Hot Rod parts from the 1970's . I once got in a stock engine with terrible running problems , it too had big , square box intake manifold that created bogs and flat spots ~ once that engine had wound up to 3,000 RPM's of course , it ran like wildfire but in traffic it was almost undrivable so I bought the whole rig for $200 or so and junked the intake and made it run well then re-sold it as a serious profit . Modifications should only be undertaken when you know what you're doing or have a good advisor to oversee your work .
Man you chevy guys are making this easy for me this week. Go get a zeinth carb if ya can. Those run great!!! I spose thats why they put it on the manly 228!!!GMC
Holly carbs Sorry for the misunderstanding, Nate. Didn't know you were talking about 350s. The ones Tom sells are more like 235 CFM, the older 5200 series. Bob
You gave the magic words, "don't car about originality". Ford, Chrysler, and American Motors all had 1bbl carbs in different brands and several were much better than a Rochester. Except for the transparent float bowl Holley used on Fords they had very little leaking problems and the see through bowl one didn't leak until some gorrilla got hold of it. Just discard the Mickey Mouse accelerator linkage and use a Ford cable with the built in return spring. This allows you to make an adaptor plate that positions the carb to where you can have mounting studs that don't clash with the Chevy studs. I like to pull the Chevy studs and replace them with countersunk bolts to hold the adaptor to the intake so the new studs can be very near the original ones. The choke/throttle cables are flexible so they work however the carb is positioned. The Carter W-1 and WA-1 (automatc choke) are also good carbs and came on flathead 6 Olds and Pontiacs. Try to find one for engines in the 200-250 ci range regardless of brand and remember it's WAY better to go with one a bit smaller than one too big.
I got 2 nicely matched Rochester Bs that do not leak from these folks: http://www.carbsonly.com/frames/carsandtrks.htm
I suppose by now you've solved you carb problem. I've dealt with Rochester B, BC and 2 barrel carb's for along time. If your carb has the correct float setting and the halve's aren't "warped" more than .003". it won't leak. I rebuild/refurbish these types of carb's all the time. I've never had one leak after rebuilding. I have a 1-barrel on my 235 and it weeps ever so slightly (normal). Problem is most guys tightened the four bolts way to much and then keep doing it way to often. This wrong method will warp the halves. If your still interested in a rebuild, let me know. Carl