LS swap gas tank vent
08-31-2016, 11:23 AM
#1
Melting Slicks
Thread Starter
LS swap gas tank vent
Question for the LS swap guys out there in regards to venting the gas tank.
Are you relying on the a vented gas cap to vent the tank?
My car is a 71. The tank has the nipple for the line up the charcoal canister but the line and canister are long gone.
I have vented gas cap.
Are you relying on the a vented gas cap to vent the tank?
My car is a 71. The tank has the nipple for the line up the charcoal canister but the line and canister are long gone.
I have vented gas cap.
09-01-2016, 02:38 PM
#2
if you are using a vented gas cap close off the line that went to the canister.
09-01-2016, 03:03 PM
#3
Le Mans Master
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Here's how I went about it-
I am running a return line - and from my understanding at idle- over 95% of the fuel is returned- basically heating up the fuel and running back in the tank- so it should be the same size as supply line.
I have a non-vented cap- and from what I have read just changing over to a vented cap (designed for a carbs) will cause venting issues- not to mention that gas smell.
I looked at the vent on the Aeromotive Phantom Pump and the manual said the vent should be 6" above the tank and use a roll over valve. In a Vette to do this the vent would have to be a couple of inches above the rear deck!!!
I added a roll over valve- connected it to a charcoal canister ( used in GM cars for the brake vacuum line) and then a vent used in marine applications placed in the antenna hole. I also ended up going w/ Russel Synthetic rubber hoses to hopefully stop the permeation of the ethanol in the gas - and gas smells.
DSCN4718 by Richard Hayes, on Flickr
roll over valve
Vent for boat hulls-
Vent in the antenna hole-
DSCN4419
DSCN4420
The other thing I did was putting a fuel cooler on the return -a few OEM new cars have it- can't imagine it would hurt ...
DSCN4904 by Richard Hayes, on Flickr
So my thoughts- no gas smell- have a roll over valve if I am ever unfortunate to roll the car. I am also adding a Ford inertia switch to shut the fuel pump from an impact. Has a reset and mounted it in the battery compartment -for easy access.
I am running a return line - and from my understanding at idle- over 95% of the fuel is returned- basically heating up the fuel and running back in the tank- so it should be the same size as supply line.
I have a non-vented cap- and from what I have read just changing over to a vented cap (designed for a carbs) will cause venting issues- not to mention that gas smell.
I looked at the vent on the Aeromotive Phantom Pump and the manual said the vent should be 6" above the tank and use a roll over valve. In a Vette to do this the vent would have to be a couple of inches above the rear deck!!!
I added a roll over valve- connected it to a charcoal canister ( used in GM cars for the brake vacuum line) and then a vent used in marine applications placed in the antenna hole. I also ended up going w/ Russel Synthetic rubber hoses to hopefully stop the permeation of the ethanol in the gas - and gas smells.
DSCN4718 by Richard Hayes, on Flickrroll over valve
Vent for boat hulls-
Vent in the antenna hole-
DSCN4419 DSCN4420The other thing I did was putting a fuel cooler on the return -a few OEM new cars have it- can't imagine it would hurt ...
DSCN4904 by Richard Hayes, on FlickrSo my thoughts- no gas smell- have a roll over valve if I am ever unfortunate to roll the car. I am also adding a Ford inertia switch to shut the fuel pump from an impact. Has a reset and mounted it in the battery compartment -for easy access.