Fuel expansion tank replacement question

GT2BH · 11-08-2014, 10:02 AM

I've been going through the old threads, and they are too old to deal with my situation. I am renewing the fuel system in my 83 SC, and wanted to delete the fuel expansion tank in the left driver side wheel well. I read about discriminator valves and other more crude solutions, but wanted to see what others are doing and pictures would be very helpful.

The setups I've been seeing are full race setups which won't be the case with me. I'd rather have something I can mount near the gas tank instead of the wheel well.

Thanks!

GT2BH · 11-09-2014, 06:00 AM

Anyone? I'm sure there are lots out there who have found a good solution

tshebib · tshebib's Garage

Here's my solution. I put a second oil cooler in the drivers side and the expansion tank was in the way. This was 2 years ago.

GT2BH · 11-09-2014, 07:11 AM

Quote:

Originally Posted by tshebib

Here's my solution. I put a second oil cooler in the drivers side and the expansion tank was in the way. This was 2 years ago.

No problems at all?

tshebib · tshebib's Garage

Nope. This started as a temporary solution with the intention of relocating the expansion tank. 2 years later (3 driving seasons) and no issues. Although I'm not sure what issues I should be looking for.

GT2BH · 11-09-2014, 10:04 AM

I'm looking at fuel check valves to enable the vapors to escape, but can't find any meaningful information on the subject. I spent all day researching this subject and still can't decide what the best approach is

tshebib · tshebib's Garage

I believe that line eventually ends up at the charcoal canister in the engine bay. Vapors are then dealt with through this I think.

Ferrino · Ferrino's Garage

What is the role of the expansion tank between the main tank and the charcoal canister? Is it to catch liquid fuel from the main tank, with vapors being sent to the charcoal canister?

E Sully · E Sully's Garage

The evap tank in the fender, #3, holds over flow from the tank. The bottom hose allows gas to flow back into the tank as the tank level lowers. The top hose is for the fumes to pass to the charcoal cannister and when conditions are right, to the intake system to be burned. The way shown in the previous picture is not a good idea. It will allow the gas to saturate the charcoal cannister.
The system works very well when hooked up properly. It keeps gas fumes safely under control preventing dangerous fumes from being inhaled or causing an explosive situation. It can also incrementally help mileage by not allowing gas to evaporate. It also vents the gas tank to prevent a vacuum forming and causing vapor lock.

cmcfaul · cmcfaul's Garage

The above fix, on my car, did not allow air into the tank as fuel was consumed creating a strong vacuum. I installed a one man bleader (brake bleader) into the hose that allows air in but not fuel out. It goes inplace of the expansion tank.

If the hose is left open gas pours out of it during hard right truns. If its plugged, no way for air to replace the burned gas.

The brake bleader worked great and is very simple. Its just a small one way valve designed for bleading the brakes. Grind it down slightly so it fits into the hose and problem solved perminitly. Hose connects just where it's supposed to so no one will even know its there (if thats inportant).

Chris

73 911 E