HELP! Gas tank vent

[Dave67]

With my tail light filler, I can't run a vented cap. I bought a small tank vent for a motorcycle, but I notice I can blow air both ways through it. Shouldn't it block air form one direction? I figure it should let air in the tank, but block gas from spilling out. What am I missing?

[Dave67]

Ttt

[luvbowties]

I think u put a vent on your ride. What u describe later is a valve?
s

[luvbowties]

Originally Posted by Dave67

With my tail light filler, I can't run a vented cap. I bought a small tank vent for a motorcycle, but I notice I can blow air both ways through it. Shouldn't it block air form one direction? I figure it should let air in the tank, but block gas from spilling out. What am I missing?

We just finished putting a Northstar in a '48 Cadillac. Drilled a hole in tank near sender-opening--where we could tighten jamb nut from inside tank--used a fitting from Lowe's for a tank: water? air? I dunno, just looked like what we needed. Ran a fuel hose from fitting up high into wheel well, & fastened a plastic, see-thru filter(about 2" in diam.) into end of hose & secured to inner fender. Filter must've been for a big truck/tractor, going by size of opening. Try to run a 1/2-inch fitting/hose, at least. Really think ours was bigger than 1/2!
hth,
sam

[Dave67]

thanks!
I just ordered an actual check valve to put on the tank. Otherwise my set up is like yours. I figured out a one-way check valve will solve the problem.

[luvbowties]

Glad u found what u need. Luck with your project. An added under-the-back gas tank can be a bear to remove/replace. Ask me how I know.

Will yours have a true vent AND this 1-way check valve too? Curious as to what type fuel/intake system u got--EFI or CARB?

One more thing: if u don't mind revealing: exactly what 1-way valve are u getting? I'd like to know, as I've studied a bit on EFI and various pump systems and am always wanting to know more. I actually do more helping friends & acquaintances w/ideas & theory[plus some hands-on] than actual start-to-finish projects by myself. Thanks.
Sam

[Dave67]

This is the check valve I'm planning to use. I hope You can see it, because I'm not sure how to post a pic. I'm just running a Regular carb, and everything was working fine, with my vent tube running up inside the bed. The only problem was when I topped off the tank, I'd have a little bit of fuel spilling out the vent tube. I'm guessing the check valve will eliminate that.

[Dave67]

Ok, this might work

[luvbowties]

Thx, Dave for the pic--it helped me visualize how it looks and works. Hoping it will stop that spill during fillup. Many options to cure same problem, and one cannot know too many!
Sam

Re: showing pics on forum: save pic, like in jpeg form, on desktop(easy to find there when named with easily-remembered name )>click "manage attachments" below bottom of message-composing box>click on "browse">navigate to "desktop" thru "browse">select the pic u saved on desktop>click "open">click on "upload"!! you're done. If I missed or mis-named a step, please use intuition to correct my error, as I believe I'm close enough.
*PS: however u did it, it showed up very well. Again, maybe another solution to one project!

[Dave67]

Sam, thanks for all your help!

[no1udknow]

Originally Posted by luvbowties

We just finished putting a Northstar in a '48 Cadillac. Drilled a hole in tank near sender-opening--where we could tighten jamb nut from inside tank--used a fitting from Lowe's for a tank: water? air? I dunno, just looked like what we needed. Ran a fuel hose from fitting up high into wheel well, & fastened a plastic, see-thru filter(about 2" in diam.) into end of hose & secured to inner fender. Filter must've been for a big truck/tractor, going by size of opening. Try to run a 1/2-inch fitting/hose, at least. Really think ours was bigger than 1/2!
hth,
sam

I would agree with this with one exception,run the hose upward, put the filter/check valve at the highest point and aim the end of the hose downward as not to hold any moisture/dirt etc or cap the end with a differential breather, something to keep dirt and bugs out of your tank. They like to crawl in to the damned'est places.

[Dave67]

good call