Fuel pressure fluxuation problems

[WildBill3]

hmmm we run no regulater in the line at all no return.-6 to a huge filter under the car to our holley mechanical HV pump straight to the carb never a problem with fuel delivery to our 830Holley hp carb.uor engine guys said keep it simple and it will work great ,and it does..WB

[Cobrabill]

Deadheading fuel pumps is not a good idea.It might work great but with a proper return line it'd work better.

[WildBill3]

Im not going against what my are engine guys are saying.im not saying your wrong,but you go to big on the return,boom ther goes my engine,i had this disscussion with them i was going to run a return and they called it foolish so i just said whatever and did it ther way .they serve a lota customers and very few where running returns on a mechanical pump.Day Automotive Independence Mo.

[Tommy]

Regarding the return line discussion: My Holley electric pump with internal pressure regulator, single line system worked fine for cruising. But on a hot day after several hot laps at the track (Roebling Road), it would develop fuel problems. I believe the extra load on the fuel pump at the track made it run hotter. The internal pressure regulator system routes excess fuel from the pump output side back to the input side, keeping it directly above the hot fuel pump. When the recirculating fuel got hot enough, it would vaporize and cause a vapor lock problem for the pump. I replaced the internal fuel regulator system with an external regulator and a return line to the fuel tank. That system doesn't allow any fuel to stay near the fuel pump long enough to vaporize. It's worked great.

[WildBill3]

well that sounds right to me to.on an electric blue holley we ran a return line also .we didnt seem to have any problems in competition last year or this year .I can see how the fuel could pickup heat under the hood ,we run this huge composite fuel log next to the carb im not sure if it makes a difference or not I just know it works for us.lotsa ways to skin a cat i guess!! WB

[Cobrabill]

Originally Posted by WildBill3

Im not going against what my are engine guys are saying.im not saying your wrong,but you go to big on the return,boom ther goes my engine,i had this disscussion with them i was going to run a return and they called it foolish so i just said whatever and did it ther way .they serve a lota customers and very few where running returns on a mechanical pump.Day Automotive Independence Mo.

If your shop called the idea of keeping fuel cool "foolish",it is time to find a new shop.

As far as the mechanical pumps go,it depends on their output pressure and what your carb likes.The blanket statement of"foolish" is ignorant.