Friends,

I'm running a holley 150gph fuel pump on my blown 177 Landy B&M 440 68 roadrunner. The pump came with a cheap holley regulator that didnt have a return style regulator. So I bought a procomp billet one that was supposed to be return style,but wasnt. I dont want the pump dead heading. What I did was make a jet with a .095 hole as the return thru a 3/8 line to the tank. I went and tested it, at idle it was 6.5 psi and was pretty flat thru 1st and 2nd gear,started to fall to 5.5 psi in 3rd and in 4th dropped to 4.5 psi. Do guys think this enough pressure at the big end being supercharged? Also is this setup similar to you guys that are running a return line? I could make another jet with a .050 hole and up the volume and pressure to the carbs? Any thoughts would be appreciated!
Thanks-Gary

The only way to have a return system (where ALL of the unused fuel is returned to the tank) is to use a return/bypass style regulator like these:

http://www.robbmcperformance.com/products/regulator_bp.html
http://www.robbmcperformance.com/products/regulator.html

Adding a "bleed" or "vapor return" to a dead-head regulator like you have done is not a bad idea but it is not the same as a return/bypass system. Still, adding a bleed to a dead-head will eliminate pressure creep at idle and reduce the chance of vapor lock. However, it does little for the pump.

The only problem I see is that your bleed hole is probably too large. I would like to see something between .025" and .040" in diameter. Any bigger just costs you excess volume with little extra benefit. If you reduce the hole from .095 to .031 the pressure will probably drop about 1 psi less at full throttle but you will still get the same benefits of a bleed.

Thank you very much. As far as dead heading the only real problem is heat as the fuel stays in the pump to long and a small orifice should work to correct it right?? I like the .031 you've suggested and will try it.With the small .031 hole it should help the pumps life a bunch shouldnt it?

It will never be as good as a true return system but the bleed will help the pump run slightly cooler, prevent vapor lock and prevent pressure creep.

The benefit to the pump is minor however as the pump will still be producing the full bypass pressure (usually between 12 and 25 psi depending on the pump design) all the time where a return regulator only requires the pump to produce the set pressure of the regulator (plus a few psi to overcome line restriction and gee forces).

Again, a bleed on a dead-head regulator is a good idea but it is not a return system and does not have the same benefits.