Hi

Doing a E85 conversion and there will be quite big electric fuel pump (MagnaFuel ProStar 500 Fuel Pumps with Filters MP-4450) and it (SBC) should produce +1000hp with NOS. I may do a little bit drag racing in future with it so I try to follow 9 second car rules by NHRA (actually by FHRA which is our local organization).

The original tank is now on the floor und I was wondering if I drill a hole for ventilation as well. The original Gas Cap is vented but I'm concerned if it flows enough air via cap and also what if I roll over the car.

So what have you put in your car/tank in similar situation? I noticed that Ecklers has a sending unit which is built to E85 specs. My old sending unit is broken so I probably buy one. Only I need to block the gas pipe since I will have larger AN fittings.

I'm planning to have a real race tank after a year or two and would be really happy if I can utilize the old tank for now.



22m hole for return line fitting



22m hole for fitting to pump/filter.

 

Here's how I went about it-



I have a non-vented cap- and from what I have read just changing over to a vented cap (designed for a carbs) will shorten the life of the pump (heat) and cause venting issues- not to mention that gas smell.

The vent on the Aeromotive Phantom Pump - 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!!!



So 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.



roll over valve






Vent for boat hulls-





Vent in the antenna hole-





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 ...



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.

 

Thanks Richard454

Cool system you have.

Just to be sure. The roll over valve is the part that creates ventilation too? And it should be as high as possible?

Further more, what happens when it is raining or I wash the car?

Planned to use the radio antenna hole for an electric main switch (Drag Race rules).