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Posted By: Dogface Best replacement carb - Fri Feb 15 2013 09:59 PM
Ok....so my OEM carb is leaking and so much so it's dangerous. It's not rebuild able to solve the leak. So should I replace it with an OEM carb or is there a better more modern carb that would function better and perhaps be less money. I have a '56 235 motor in my 49 Chev half ton. Eventually I'll go to a dual carb set up but that may not be soon. I see rebuilt Rochesters costing $350 !!
Posted By: Mr. Lang Re: Best replacement carb - Sat Feb 16 2013 09:59 AM
What's wrong with it that it can't be fixed?

Where is the leak coming from?
Posted By: Dogface Re: Best replacement carb - Sat Feb 16 2013 10:38 AM
I can't remember the name of the part but it's a (I think) shaft that goes thru the bottom and across. The shaft looks to have a bushing pressed into the outer 'shell' of the carb. This guy I'm using is pretty good at these old trucks and knows his stuff.
Posted By: Mr. Lang Re: Best replacement carb - Sat Feb 16 2013 10:58 AM
Do you mean the throttle shaft? If the carb has been rebuilt, and the float level etc. is correct, then usually the trouble with a worn throttle shaft, is an airleak. The body can be drilled, and a brass insert put in to tighten up the play. You might see some wetness around the shaft when you first start up.

But, you can usually find a better carb at a swapmeet, or through friends, or the classifieds here on the bolt. No carb is going to work well unless it's rebuilt. Around here, a decent carb seems to run from $40-$60 at the swapmeet, and then you go to FLAPS to get a rebuild kit.
Posted By: Dogface Re: Best replacement carb - Sat Feb 16 2013 12:01 PM
Thanks Chris,

I guess that's the part...not sure but I was also just researching about a replacement and on some older threads many seem happy with a progressive two bbl in place of the stock one bbl. Do you have any comment on that ?

This shaft is not just wetness...it's visibly pouring out and being near the exhaust manifold makes me REAL nervous...
Posted By: DADS50 Re: Best replacement carb - Sat Feb 16 2013 01:05 PM
Sounds like a flooding issue

Debris in the carb,

Has the carb been rebuilt recently?

I saw a carter 2100s on eBay recently, rebuilt with warranty
Kinda expensive but ready to bolt on
Posted By: Brad Allen Re: Best replacement carb - Sat Feb 16 2013 01:13 PM
Nice truck, I would fix it ASAP $350 may seem cheap in light of an engine fire?
Posted By: Mr. Lang Re: Best replacement carb - Sat Feb 16 2013 03:20 PM
Like DADS50 says, sure sounds like debris in the needle and seat, or some float issue.

The B carb is super simple, and there are great instructions in the shop manual for checking the float level etc.

I've never had a two barrel carb so I can't comment on them.

I have had a hole in my B float, that made gas pour out of the car like you describe though. Bought a new float for $12 at the FLAPS. Other than that, the B that's on my engine right now has been trouble free for 12,000 miles.

Posted By: brokenhead Re: Best replacement carb - Sat Feb 16 2013 05:36 PM
my carb did this several times, you are overfilling the bowl, whatever the reason. Like has been mentioned, debris stuck in the needle valve, sunk float, I also had an issue with the float actually resting on the bottom of the bowl after the gas evaporated, and apparently the new fuel formulations are very sticky after it dries out and holds the float down and lets the fuel flow freely. Set your float DROP as well.
Posted By: Dogface Re: Best replacement carb - Sat Feb 16 2013 06:02 PM
Originally Posted by Brad Allen
Nice truck, I would fix it ASAP $350 may seem cheap in light of an engine fire?


You sure got that right. As for rebuild, I know you guys know your stuff but the guy doing my work seems to know too. There is a rod on the bottom with a brass bushing. It's leaking there. He says that can't be fixed...or at least not easily. I'm leaning strongly toward the Weber 2bbl progressive. Guys seem to like that set up. One of the guys on SB may sell me his double setup incl manifold...

Oh, and Brad, thanks for the compliment....I still have not named her....taking suggestions...was thinking of Loosey since she rattles a bit, but that didn't stick...
Posted By: truckernix Re: Best replacement carb - Sat Feb 16 2013 06:31 PM
I wonder why the guy would want to sell his double setup if it worked well for him.
Posted By: brokenhead Re: Best replacement carb - Sat Feb 16 2013 09:09 PM
I need to see a video of that leaking, I can't think of any brass rod that would cause leakage of that sort. OH, and some of the reasons someone might want to sell the dual carb setup is it won't fit with fenton headers, (I had to get a FENTON intake, the edelbrock wouldn't fit), maybe they got a wayne 12 port and it won't fit that either, he went with a V8, had clearance issues with the fender braces, simply changed his mind. There doesn't need to be an ulterior motive, no one mentioned whether it worked well for the fella or not, as a matter of fact, it didn't say whether it has even been installed on an engine period
Posted By: Joe H Re: Best replacement carb - Sun Feb 17 2013 08:49 AM
A progressive two barrel will not work on its own, you need two of them. One is just to small for the 235. This is why they work so good in dual setups.

Unless the the carb has a direct hole in the casting letting fuel out, it can be rebuilt and made to run pretty decent. Any fuel running down the sides or out the shafts is from overflow or leaking gaskets.

First thing to do is add a small fuel filter right at the carb inlet. Then open the top and remove any trash that you see. Look under the needle valve and flush the area. Check the float for leaks and be sure it floats, replace it if in doubt.

Find another carb mechanic.

Joe

Posted By: brokenhead Re: Best replacement carb - Sun Feb 17 2013 08:57 AM
I agree with joe on all points, especially the part about finding another mechanic. The only thing I could add is you could learn to do this yourself, that way you know exactly what is going on. The rochester is about 1 step above a briggs and stratton in complexity.
Posted By: tclederman Re: Best replacement carb - Sun Feb 17 2013 09:02 AM

There is at least one Holley-Weber carburetor (2300 or 5400?) that is a progressive 2-barrel carburetor that is big enough to not have to be used in pairs on 235 engines. Tom Langdon sells at least one type of these progressive 2-barrels ( 32/36 DGEV). Supposedly, these are 300 CFM carburetors. Two of these would be too much, even for a 261.

The Carter-Weber 740 (some call it a Holley-Weber 740 ?) is a much smaller progressive 2-barrel carburetor (used on 1600 cc Pintos, among others) and needs to be used in pairs on 235 engines. Tom Langdon sells these in pairs. Two of these are a little too small for a 261, but should work very well on a 235 (which is what Tom seems to usually recommend them for use on).

I agree with Brokenhead regarding trying to rebuild an original Rochester (unless it is leaking from a a pivot-shaft - that is not a simple parts-replacement rebuilt).
Posted By: JiMerit Boltr#43 Re: Best replacement carb - Sun Feb 17 2013 09:39 AM
Looking at your beautiful truck so nicely done I'd make every effort to stay with a stock carb. My 53 was flooding really bad, gas everywhere, turned out to be way to much fuel pressure. Picked up an adjustable fuel reg. at Napa and now no flooding in the engine room. These carbs do not like pressure over about 2 lbs tops.
Posted By: Dogface Re: Best replacement carb - Sun Feb 17 2013 11:15 AM
Interesting... I'll see if my guy mess. the fuel pressure ...
Posted By: Dogface Re: Best replacement carb - Sun Feb 17 2013 11:22 AM
First, I'll have my guy test the fuel pressure. The guy I'm thinking of buying the set up from had it installed on a 235 which worked fine but he changed motors to a 261....too small for that. He's a mod here.

I may just do as many have suggested and have this Rochester repaired...Joe Hand has asked me to send it to him...would be nice, in a way, to keep it stock.. Lots of other projects to do in the mean time.
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