Fuel System: Porous Carburetor Bowl

[reichsrundfunk]

Hey guys,

Does anybody have a good, effective remedy for a porous carburetor bowl? Since having the problems recently with my carb which mysteriously all happened when we had switched to winter formulation- I have noted that my Stromberg WW carb has developed the porous bowl symptom. The outside of the carb surrounding the bowl area appears slightly moist (not really damp or wet) and if the car sits a couple days the bowl is dry and takes longer to start since the carb needs to get fresh gas pumped in from the fuel pump. More annoying is the smell of gas because the carb body is damp.

Of course I suspect part of the problem is the wonderful ethenol we get to enjoy thanks to the Government. But even if not, I need a solution that won't be degraded by the ethenol.....

George

[karterfred88]

I believe the bowl portion of the carb is made of pot metal. As such, it is very hard to come up with a porosity solution that is permanent. If you are not afraid of taking the carb completely apart, you can try using a fuel resistant fuel tank sealer applied by brush or spray in thin coats to the insides of the bowl and under the cover where exposed directly to fuel. The danger is that if it delaminates from the base metal and flakes off it may clog your jets. A two part epoxy paint may also work or a catalyzed urethane, but I'm not sure how well they'll stick to the pot metal. Would require a thorough cleaning and etching, which might be too aggressive for the pot metal. I have seen some claims by carb rebuilders that plate the carb bodies or give them a "dip" that is supposed to stop it, but have no idea if or how long it would work against the alcohol's corrosive nature.

[rockne10]

At this point it is difficult to find a Studebaker carb that has not been rebuilt at least a half dozen times and, with each rebuild, more of the chromate seal has disappeared. I will no longer rebuild one more than once and, if it doesn't suit me, I send it to T-bow. His rebuild includes re-chromating the carb body and I've never heard a negative comment about his service. I'm sure there are others of equal quality. I just stick with a known entity. You will see him at every major Stude swap meet.

Dave Thibeault (T-bow)
13 Nick Lane
Maynard, Mass. 01754
(978) 897-3158

[jclary]

Too many "backyard" carburetor rebuilders use the wrong solvents to clean a carburetor. There is a reason parts stores sell a specific solvent called "Carburetor Cleaner." Solvents like lacquer thinner and MEK will break down the sealing material. When that happens, the carburetor will forever ooze gas unless the body is stripped, and re-sintered. I once had a customer who contracted to do this job. They had huge pressure vessels that could seal a couple hundred carburetor castings at a time. There were several foundries that sent them truckloads of castings. Most of their business seemed to be for small engines, like weedeater, chain saw, and mower engines.

If your carburetor is forming droplets of gas on the bottom of the bowl, it probably is leaking. If it is discoloring around the bowl gasket or inlet fittings, you might get lucky and find that new gaskets will cure the problem. It could be that the ethanol gas is attacking your gaskets allowing gas to perk out.

[reichsrundfunk]

Too many "backyard" carburetor rebuilders use the wrong solvents to clean a carburetor. There is a reason parts stores sell a specific solvent called "Carburetor Cleaner." Solvents like lacquer thinner and MEK will break down the sealing material. When that happens, the carburetor will forever ooze gas unless the body is stripped, and re-sintered. I once had a customer who contracted to do this job. They had huge pressure vessels that could seal a couple hundred carburetor castings at a time. There were several foundries that sent them truckloads of castings. Most of their business seemed to be for small engines, like weedeater, chain saw, and mower engines.

If your carburetor is forming droplets of gas on the bottom of the bowl, it probably is leaking. If it is discoloring around the bowl gasket or inlet fittings, you might get lucky and find that new gaskets will cure the problem. It could be that the ethanol gas is attacking your gaskets allowing gas to perk out.

In my case, I acquired the car all original with 37000 miles on it (verified and documented). No work was ever done on the carb from what I could see, and when I opened it up it ws obvious it had never been worked on or cleaned. So when I cleaned it I used Gumout Carb Cleaner (profusely) and that made a huge difference. When the gas reformulated for winter driving is when I began to notice the smell and began experiencing issues with the inlet valve and float. Thats when I replaced the valve and gaskets,etc. But it clearly had never been rebuilt before. If it drives me crazy enough I'll just replace it with a rebuilt from Dave T.... But other then the occasional smell it's operating great. BTW: no droplets of fuel on the outside of the bowl, just feintly moist.......