venting a weber (1 Viewer)

Joined
Feb 10, 2011
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Fort Collins, CO
Hi,

I've searched for this but can't find a definitive answer. I'm tired of my Weber's fuel bowl venting to the atmosphere and the accompanying gas smell. I want to seal up the top cap, drill a hole in the tube-like thing that is in the cap and then route a hose from the top cap to the line going to the charcoal canister. I still have the complete canister with all necessary valves. The hard line that used to go to the stock carb is plugged right now and I plan to use that.

Anyone know if this will work? My concern is mainly that you can't just seal off the fuel bowl, it needs air while the truck is running or else pressure builds up inside it. (As I understand things...)

Thanks is advance for any help!

-Andy
 
Joined
Jan 18, 2011
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Seattle
er, the DG's (32/26 and 38/38) vent into the air cleaner... don't see how to beat that?

t
 
Joined
Feb 10, 2011
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Fort Collins, CO
Its the gas smell that creates that I'm trying to avoid... that and the idea of losing gas (however little that may be) is annoying especially at 3.50 a gallon
 
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Mar 18, 2008
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Washington, UT. The Promised Land
 
 
If you still have the stock exhaust manifold, it is causing far more heat in the intake and carb than a header would, thereby turning more gas into vapor. I ran a Weber for many, many years and I don't recall having your issue, but I ran a header with a fluid heat riser.
 

ntsqd

technerd
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Apr 26, 2007
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Upper So. CA
 
 
A carb is a pressure differential device. Venting the bowl to somewhere else opens you up to varying air/fuel ratio as the restriction in that hose changes. I have seen 1/2-1600 cars run the bowl vent outside of the carb to prevent flooding in the high speed rough stuff, but those hoses are regularly 'washed' by liquid fuel.....
Can vent the bowl externally to the charcoal canister, just don't plug the opening inside.

Put an 1/8" thick piece of aluminum sheet under the carb. Make it as big as you reasonably can, cut holes for small stuff that might have to poke down through it. That will help some by both shielding the carb from heat and by dissipating heat after a hot shut-down.
 
Joined
Feb 10, 2011
Messages
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Location
Fort Collins, CO
Interesting info. Doesn't the aisan vent the float bowl to the charcoal canister or am I mistaken? I thought it had a valve that gave fresh air during engine operation and connected the canister when not running.

Do you mean another spacer under the carb made of aluminum? I do still have the insulator with heat shield attached. Maybe when I get my 10" paper filter on there I wont notice the smell anymore. That Weber filter doesn't look like it filters very much...
 

ntsqd

technerd
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Most OE's had a vacuum operated valve that closed the canister bowl vent to the carb while the engine was running, but opened that vent when the engine was not running. Some of the Holley clones of the DGV used on Vega's and Pinto''s had the vent features cast into the carb top. I don't know if such a DGV carb top will fit and work on the DG, but it might be worth looking into.

Not just a spacer under the carb, but a sizable heat shield.

I wouldn't count on any filter to do much for holding back fumes.
 
Joined
Apr 5, 2015
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41
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White Sulphur Springs, MT
http://board.marlincrawler.com/index.php?topic=46859.0 This is a nice little write up on a Weber 38/38 mod. I would use a tap before hammering in a pipe... It talks about stalling on incline also it is for jeep. I don't know if it would work on Toyota charcoal can as it is shut to float bowl during normal operation. If one left out the JBWeld step it would be pointless. I also want to hook up the CC to my Weber 38/38 but have not found a good solution. With this mod, could one just eliminate electric valve at the can and run ported vac to purge on can?
 
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Joined
Feb 26, 2012
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WPB, FL
Are you using a fuel pressure regulator ? The PO didn't use a regulator on my Weber, it had a constant gas smell.
 
Joined
Apr 5, 2015
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Location
White Sulphur Springs, MT
For what its worth, I have to run a regulator(Holley) as well as low pressure electric fuel pump(Holley)to get away from serious leak down problems with the Weber. Three psi MAX going into Weber. The hoses in the passenger rear panel were also quite rotten and leaked fumes into the cab. Andykrow is your return to tank line from the old charcoal canister capped off? May be a source of some fumes if not...
 
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