Fuel pressure problem..I'm at a loss.
@512Stroker Im in the group that says a turret style mechanical can feed a 512. Let me back it up with this:
This data is for a 325 HP 340 but even if you double the horsepower to a very hot 512's potential 650HP all 3 besides the Holley 80 are still capable of feeding that per that graph..and he's losing the fuel pressure at a few seconds out of WOT. Wish we could see if the pump rod is seizing up after a WOT run, then any mechanical pump you run is going to go to zero. Maybe worth a shot to remove the pump rod and check it for galling or run a crocus cloth over it to knock down any high spots? I think the OP may need to get a remote gauge and monitor when the pressure really starts to drop. The pumps are proportional to engine RPM to a point but by design, they top out at the prescribed PSI or close to it under no load conditions.
@512Stroker Im in the group that says a turret style mechanical can feed a 512. Let me back it up with this:
This data is for a 325 HP 340 but even if you double the horsepower to a very hot 512's potential 650HP all 3 besides the Holley 80 are still capable of feeding that per that graph..and he's losing the fuel pressure at a few seconds out of WOT. Wish we could see if the pump rod is seizing up after a WOT run, then any mechanical pump you run is going to go to zero. Maybe worth a shot to remove the pump rod and check it for galling or run a crocus cloth over it to knock down any high spots? I think the OP may need to get a remote gauge and monitor when the pressure really starts to drop. The pumps are proportional to engine RPM to a point but by design, they top out at the prescribed PSI or close to it under no load conditions.
