I am in the process of converting my dragster from gas to alcohol. I have a mechanical pump and carb. I recently purchased a 3 way shutoff valve to mount to the top of the pump(outlet). Off the 3 way valve, I plan on running one line to a fuel log with a by-pass regulator and the other line back to the tank. When looking at the 3 way valve it appears that when on(open) all three passages are open and when off(closed) just the inlet and return passage of the 3 way are open. When on(open), should all 3 passages be open? I assumed only the inlet and outlet would be open. New to alcohol. Thanks for your time and assistance.

Something is wrong. The valve when open should be straight through. When closed all the fuel is diverted back to the tank.

What your describing sounds like the 3 way valve needs an Enderle type set up and a "pill" to adjust fuel psi on the 3rd leg return line. With the regulator at the end of the fuel log do you plan on running a return from there ? Could you just cap the return line off the valve ?

i have run in to some from apd that have to be turned upside down to work,they were assembled wrong

I think that is what happened. When open all three passages are open. I think I can pull out the pin and rotate the shield 180 degrees so that when "on" the return is closed. I ordered an APD and was confused so I ordered one from Enderle and must have got the wrong one. Thanks

Thank you everyone for your replies. I think I realized what is causing my issues. I ordered the wrong valve.

Thanks

quote:

posted November 19, 2020 11:29 PM Hide Post
I think that is what happened. When open all three passages are open. I think I can pull out the pin and rotate the shield 180 degrees so that when "on" the return is closed. I ordered an APD and was confused so I ordered one from Enderle and must have got the wrong one. Thanks

i reconfigured mine to work with flow normal .pulling the pin is what i did

Pretty sure you want to leave it the way it is for the reasons shown in the good vibes description above. Stick a check on the return port with a 30 psi spring. Otherwise, if you configure it like a typical mfi shutoff and don’t have a check somewhere, your going to see 200 psi at the regulator inlet. Unless you have one of those low pressure BLP pumps, in which case you could run it either way.

I’m running a 0 1/2 Rons pump, same pump I ran with my injection system. Using an Aeromotive bypass regulator. 7 pounds of pressure going downtrack and no problem with it whatsoever. It’s simply bypassing 90 percent of the fuel. I’ve run this same deal with an alky carb and now a gas carb.