Previous owner ran a mech. fuel pump with the bypass/return at the pump blocked off, but ran a return line from the end of the dual Holley feed line back to the tank. He used an orifice to reduce loss of all fuel pressure back to the tank. (Fuel pressure is as high as 7.5 at idle) Is there any problem with not using the bypass on the pump and not running a return line? I'd just like to simplify things. Should I be running a regulator? Thanks in advance for your replies. This Board is awesome.
Hi Ramin, The factory basicly put the return there to keep the fuel cooler..to help avoid the gremlins of vapor lock by keeping everything circulating. It's an old racers trick to block it off to make sure that all the fuel the pump is pumping is going to the carb. With "more horses to feed" at higher RPM's with that return line there's always the chance the pump will not be able to keep up and the engine will begin to "nose over" from leaning out earlier than without it...at least a stock mechanical pump whether it's a Stage1 pump or not. A stock mechanical, whether it's a Stage1 pump or standard, doesn't produce enough pressure to overcome the needle and seat to require a regulator in my opinion...especially if using a Holley which can handle more psi than say a Q-Jet. Hope this helps..
