Hi Guys, its probably somewhere on here, but have had no luck searching.
Does anybody know the Specs for original Merc Fuel pump (cool Fuel) for 2001 MAG MPI Horizon (454)
im after GPH mainly and at what pressure. I think they where 46 psi from memory.
Thanks for your help

The regulator was 43 psi, the pump itself is capable of more pressure with a different regulator. I don't know flow but maybe someone else does.

If your pressure is staying up, you have more then enough flow
I'm running cool fuel and have 530 HP (tuned at 40 psi) with fuel return to tank and at WOT I'm still at 40 psi

Hi Guys, Original question Hi Guys, its probably somewhere on here, but have had no luck searching.Does anybody know the Specs for original Merc Fuel pump (cool Fuel) for 2001 MAG MPI Horizon (454)
im after GPH mainly and at what pressure.
I will try to be more clear about why and what is happening. The reason i asked was after rebuilding engines (twins 454s) Originals2001 MAG MPI Horizon (454) with all new Holley EFI ecu's, Smart coils, Cam sync, crank sensor Hall effect. Approx 550-600 HP
Using original single centre fuel rail, coming in at front and exiting at rear to Turbo smart reg and then return to tank. Powering the fuel rail is a Pierburg 360 LPH @ 3 Bar External Fuel Pump. With all new 8an SS braided fuel line.
The pump location is similar to original position of the Cool fuel setup except on stringer not engine (easier to get at).
So my issue is - they were up n running fine idle really nice, base fuel set up on the careful side, but after running for only 20 mins at 3200 i noticed some serious blow by!!!! After returning -pulled upper stuff off then heads and hello - Pistons 5-6-7-8 Mainly 7-8 melting top thin edge.
After 2 weeks of debating the cause I'm at fuel starvation as both engines where the same problem at same pistons. And because the problem was so selective i believe fuel starvation over any advanced timing problem.
Both engines - same problem. I have now put new slugs in, rings bearings etc... ready to go but - i want to be convinced that i know what caused this... Hence why original thread asked for specs on original fuel pumps as they may have had better lifting capacity then my new ones.
When problem occurred pressure was reading 46 psi this was at sensor input on regulator.
I think Artic friends has been here before!! any input much appreciated.....before i try again....