G'day

Now having both my low and high pressure pumps and surge tank i need to decide on fittings and hose sizes.

The plan is to go from the tank to the low pressure pump (holley red) from that to the surge tank, from the surge tank to the high pressure pump (vl turbo, i know its holden but they are good pumps), the high pressure to the fuel rail, fuel rail back to the surge tank, and the surge tank over flows back to the tank.

The fittings on the vl pump inlet side are about 1/2 inch, the outlet is 5/16th the same as the lines to the front of the car. The surge currently has a 1/2 inch fitting at the base to feed the vl pump, so its not a problem. The problem i have is the holley pump doesn't come with fittings, the outlet on the tank i think is 5/16th, do i just match whatever the tank is? How big should the overflow be from the surge tank back to the main tank? What size from the holley pump to the surge tank?

Also what do you seal the screw in ends of the fittings with?

Cheers

Use the white sealing tape or some loctite/permatex designed for the job.

As for hose sizes, if the tank output is 5/16", just go 5/16" on either side of the holly... unless you've got a bigger barb on the in port of the surge tank. If that's the case, match the output of the holly to the input of the surge tank.

Vent line from the surge tank only needs to be little. most of the good people who use a surge tank setup will put a restrictor in the vent line to help pressureise the surge tank. Reason.... high pressure fuel pumps are no good at sucking, only pushing.

So by restricting the vent line, you force the low pressure lift pump to pressureise the surge tank to make it better for the high pressure pump.

also run the return line from the fuel rail back to the main tank

G'day

Any reason for the suggestion of returning the fuel rail back to the main tank.

My mate who has a rally car told me that it should return to the surge tank to keep as much fuel in there as possible.

As for the fittings size that was what i was thinking, nits only the return from the surge tank to the main tank i have to work out.

Cheers