Hot Rods Pre War Dirt Track fuel tank hand pump questions

I'm changing my 30s Model B powered car (dual 97s) back (from electric) to using the hand pump. The hand pump is still in place and the tank is still set up with a cap that seals with fuel tank air connection. It's for the stuff in between I have questions. First does anyone have info for the air line dia? I suppose air line ID=fuel line ID or just fitting dia on pump or tank. Probably overthinking but before I buy fittings/check valve/line I thought I would ask people who will know what was typically used. I was also thinking a larger air line, fittings aside, may help a little if the tank is full (small air volume), may serve as an air accumulator. Then wondering if people used an actual small air tank before the fuel tank for longer races (needed max fuel) and less initial pumping. Thanks for any ideas.
steve

 

Old time trick : use the stock "B" fuel pump as an air pump to pressureize (mildly) the sealed tank & push the fuel to your carbs(sure saves a lot of hand pumping!!) If you want to save the hand pump to "wow" the crowd, go right ahead, but usually you'll have enough gas left in the carb to fire the motor & get enough pressure to move the gas in the line . Successfully used this idea to feed Methanol to a flathead sprint car & never flooded or ran lean! If you fear that you'll have too much pressure, you can always install a pressure regulator. It's OK to PM me if you have questions.

 

drtrcrV-8 Great idea, thanks! It's the sound of the electric pump that bothers me before I start it up. It just seems wrong to me. I had never heard of using the Ford fuel pump, that sounds really interesting. My project just took a turn, thanks again.

 

It actually did a couple of things : Removed the need for a battery & reduced the car weight of both battery & electric pump, looked "original"(nobody paid any attention to what the pump was actually doing), & definately was "KISS Principle". Most racing associations DO NOT allow electric fuel pumps even with a battery "kill switch" due to the risks associated with ruptured fuel lines in a wreck!!

 

My guess is that those hand pump systems were cobbled together from various pieces and never the same way twice. I can't imagine that complete kits were sitting on a shelf at the parts store. So the sizes of any air and fuel lines must have been pretty circumstantial.
I know details are important in a build like yours but I think you have some wiggle room in this case.

Side Bar:
I bought a vintage, brass, beer tap pump a while back just because I like how it looks. It's crossed my mind that it could be repurposed as a "hand pump" for the type of car that you're building.

 

drtrcrV-8 and shift wizard

Thanks for the input, it really does help me. Keep it simple and don't get caught up with right/wrong, if it doesn't do something, try something else. The B fuel pump is the plan so I'm looking for one. Seems like rebuild kits are easier to find than the pump. I can always use the hand pump to prime the tank air pressure if needed but thats more connections that can leak. I'll start (no pun )with the straight line, pump to tank.

 

oh, and the brass pump is awesome! That would make a very cool tank pump

 

Awesome article Gofannon, thanks! Beautiful car. More confirmation of using the fuel pump for air as drtrcrV-8 suggested and priming with a hand pump.
steve