Stromberg WW leak

I'm somewhat familiar with this carb having rebuilt several for Studebaker V-8s... unfortunately it seems that "they all do that." I'm not sure which joint you're describing as leaking but what I find most often is that the upper part of the carb is warped and won't seal to the main body correctly. Sometimes a double gasket helps... but what I suspect is the root of your problem is that when the engine is shut off the gas is percolating out of the fuel bowls, going up through the passages in the carb, and then out and onto the throttle plates where it runs both into the manifold (making it hard to start after sitting a few, but only a few minutes) and also out the throttle shafts and onto the manifold (which is a little unsettling because it lands right on the exhaust crossover.)

I'm not really sure what a good fix is, because they didn't do this when new, but that's not because of an issue with the carb - it's because gas was different back then and didn't boil so easily. But you might try lowering the float level 1/16" or so and seeing if that helps any without causing any driveability issues. Other than that, you may need to have the throttle shafts rebushed to keep the fuel from running out there when it inevitably boils over. Still not ideal but at least it would be contained inside the manifold. Finally you might want to get a thin heat insulator to replace the gasket under the carb to keep it from getting so hot.

good luck,

nate

Besides Nate's suggestions, they started putting gas return lines on them to avoid the vapor lock/ puking gas out issue with carbs.

Does yours have a return line that maybe went rusty and got disconnected?

They do sell inline fuel filter with 2 outlets and one could be fabbed up I suppose.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail >

and recently it has been leaking gas from the lower plate joints on both sides sometimes a little and sometimes a lot, it only leaks when the engine is off. Does anybody know how i can stop my carburetor from leaking?

first off the carburetor was actually a rebuilt my father bought from holley 2 or 3 years ago, he put it on after having the engine remachined, and it sat untill recently when we finished rewiring the old truck. and the plate i was talking about was the Throttle plate. and nothing appears to be rusty. i will post updates on my progress, i do have the origional Carb, its the same model and it never had a problem leaking so we were thinking about replacing the lower half and rebuilding it. The upper part of the carb sat in cleaner too long and was damaged. but tell me if you think of anything else

Thanks for all the help

Mat

-- SweptlineTrucker

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There are two things you need to address here: The leaks themselves, and the causes of fuel having occasion to travel through those leaks on engine shutdown.

Nate's suggestion is a good one (double-gasketing the junction between the main body and the throttle body).

You'll also want to check to see that the throttle shaft isn't loose in its bushings-that's another common leak point, and even the less-disreputable carburetor "remanufacturing" factories like Holleys scarcely ever rebush them. One good test for this is to let the engine idle and spray carburetor cleaner at the base of the carburetor where the throttle shaft passes through, on both ends. If the engine idle changes noticeably or if you see the carb cleaner rapidly sucked into the carb at that junction, you've got excessive throttle bushing sideplay.

The necessary rebushing can be done, and warped castings repaired so that they seal, by any of several skilled carburetor rebuilders (not the same as "remanufacturers"). One such goes by the name of the Old Carb Doctor, 800-945-CARB. You mention you've got the original carb. Originals, no matter how grimy and old, are always easier to refurbish to as-new condition than abused "remanufactured" units, so you may want to carry on living with the annoyances of the "reman" unit while you send off the original for a proper refurb.

Mike's babble about the "fuel return line" on your Dodge is his customary hallucinatory babble. There were no Stromberg WW carburetors of any year with fuel return lines. So, there's no such a line to have rusted or otherwise become damaged. His basic idea is sound, though: You need to reduce the effect of percolation, which is when heat transferred to the fuel boils it when the engine is shut off. There are several ways of tackling this problem. A carburetor heat shield can be made in the form of a carb-to-manifold gasket that extends outward several inches in every direction. An extra-thick carb-to-manifold gasket also helps insulate the carb from manifold heat.

Often, percolation begins not in the carburetor but in the fuel line that runs from the fuel pump to the carb. You can rework this line to significantly reduce heat transfer to the fuel: Remove the metal line that runs from the fuel pump to the carburetor. Install a 5/16" IV-flare-to-5/16"-hose-barb brass fitting in the fuel pump outlet and another in the carb inlet. These fittings can be had from any well-stocked hardware store that carries the Dorman "orange drawers" line of springs, fittings, etc. The Dorman part number is 492-024; Everbrass number is 1791.

Between these fittings, run a length of 5/16" I.D. _fuel injection_ hose marked SAE 30R9, not the lower-test old-fashioned 30R7 stuff that doesn't do well with modern gas formulations over time. Be sure to get fuel injection hose clamps, too. Route this line carefully away from sources of heat (exhaust manifold...) and away from moving parts. Make sure to leave enough slack in this hose so that it is not stretched taut at any point.

Think carefully about how you place the fuel filter, and use one with a

*metal* can, because the plastic ones sometimes don't do well with current gas formulations. The fuel filter should be installed in a vertical or near-vertical orientation, inlet at the bottom and outlet at the top, and in as cool a location as possible.

With this setup, a lot of the b=ECtchy hot and cold start problems disappear, because you're no longer boiling fuel in that metal line when you shut off the engine. In extreme cases where it's not possible to isolate the fuel line sufficiently from engine heat, then a vapor-return line such as Mike was trying to talk about can be added. It involves the use of a 3-port fuel filter. The two normal 5/16" ports are present, as well as a smaller 1/4" port near the top of the filter. One such filter is the NAPA #3040. You connect a new 1/4" fuel line hose to that 1/4" port, which must be pointing upward. Loop the 1/4" hose in a full, loose 360=B0 loop, then either run it clear back to the fuel tank where it connects to a new 1/4" nipple you've added to the fuel tank sender plate, or -- preferably -- form and install a hardline for the long length of the truck.

DS

Actually it's the top plate that I was thinking of; that's where I've always found warpage on WWs. The throttle body is fairly beefy; I can't see that warping.

This is where I have seen carbs leak on hot soak; I ASSume this is actually what's happening here and that it's due to percolation.

I've heard nothing but good things about Daytona Parts as well, although I haven't had an occasion to use them yet. There are DIY rebushing kits available for some carbs, but probably only 4bbl units; not sure if any of them use the same size throttle shaft as a WW.

Oooh... I'm gonna have to check when I get home; I thought (although I may be confusing them with the later "R-series" engines) that the 57-58 Studebaker models with a supercharger had a return line. So there :)

Alternately, take a couple thin sheets of stainless and punch holes in them to match the gasket. Alternate these with thin base gaskets. Apparently this works; Mr. Gasket sells a stack like this for AFBs and people that have tried them have claimed that they worked. (of course, I have only had the problem you describe with one AFB, and that was because it had a stuck float.)

A block of phenolic machined to match would work as well, or dense hardwood (seriously!)

I have to admit I'm not a huge fan of the hose, although I'm sure it works as you say it does. I'd definitely invest in some of those plastic coated clamps and make very sure it never touched anything metal.

Another thing that I've seen done on older cars is to wrap the fuel line with asbestos cloth; obviously you can't do that anymore but you can get heat protective tape and sleeves. I'm using some on my '55 right now to protect the vacuum hose for the dist. and the wire for the electric choke (the stock carb. used a hard line to the dist. which an Edelbrock does not have a provision for; and obviously there was no electric choke. There's also no handy bolts nearby to which to attach anything to which to zip tie the wire/hose.) Not sure how hot it gets inside that sleeve, but it passes right over the exhaust crossover and I've had no problems.

Eh, I have not had a problem yet with the Wix brand plastic ones, although I'll probably eliminate it on my '55 as I finally found a NOS fuel pump with the "stone" filter and glass bowl built into the inlet side (would rather catch the nastiness before it gets into the check valves rather than after)

Yup, or alternately you could solder or braze a hose barb or female flare seat into the filler neck, if that is more convenient.

I would like to think I wouldn't have to say this, but if you are going to solder or braze anything onto the filler neck, this should be done with the filler neck removed from the vehicle and thoroughly cleaned to remove any fuel residue. (hey, you never know who might be reading this) Worst case would be that you would have to put it right into the body of the fuel tank, but unless you REALLY know what you are doing and take all precautions, that's best left to a pro (not going to say I haven't done it, but do as I say not as I do.)

nate

No, the throttle body usually doesn't warp, but the bottom gasket surface of the main body can do. I agree the top plates can warp as well (just like the Carter BBS/BBD carbs).

For carburetors designed with field-serviceable bushings, yes. For the likes of WWs, BBSs, BBDs, WAs, etc...no.

That's certainly possible. I was talking about Chrysler products, since that's what the OP's working with.

FWIW I am pretty sure I have seen some available for either AFBs or Q-jets... basically an extra-long drill bit and some Oilite bushings. Never bought one though.

nate

you might check the in-line connection, tighten if necessary while using a back-up wrench, and any gasket area for leaks.

If it has cap screws over the jets, check for a faulty / broken gasket, and looseness.

mho vfe

Yep. Some Holleys are like that, as well. You can rekit and swap throttle body-to-float-chamber gaskets until you are blue in the face, but the bowl will still drain down (on teh Holley). You could try milling the surfaces, but they'd just warp again, so why bother?

I've seen people throw away brand new carburetors, in disgust, and switch to a different brand (usually an Edelbrock Quadrajet clone).

Another winner was the Motorcraft 2700 VV. What a nightmare. Even in California, it was deemed legal, under emissions standards, to replace those pieces of shit with a standard fixed venturi model, like a 2150xx..

And those damned Stromberg CD's that were common on Volvos and Jags, always failed diaphragm (making engine burn VERY rich, but still ran, and was driveable, though barely).

Fond Memories... LOL!