Can someone educate me on fuel pressure? I installed a Carter ss series self regulating mechanical pump M60454 rated at 7 min 8 max psi to fuel a new 650 Holley 4150 double pumper that Holley says needs 5-7 Psi. I’m running a 3/8 steel line from the pump to the carb through a billet Holley 40 micron filter before a pressure gauge just in front of the first of two fuel inlets to the carb. The carb still has Holley filters in the inlets.
The car runs great on acceleration and idle but the gage only reads 5 psi. Shouldn’t it be 7 as thats is that’s carters minimum? Shouldn’t the pressure be dictated by the pump, and only be higher with restrictions like the filter or the 90 degree /T finlet fittings at carb inlet? Wouldn’t it only be lower with a return system or a leak? Confused as to where 2 lbs pressure would be lost. Is it because the carb is dictating it as the last restriction in the chain?
Given the car runs great I don’t see a need to change anything but I am bugged I don’t understand the dynamics here. I’ll probably change out the gage just to check it’s accuracy nut that seems like an easy out.
thx steve
Connect With Us