Mechanical Fuel Pump Arm Movement

[76SeaRay]

Granted the last manual fuel pump I installed was my old 73 Ford pickup but I am wondering about the travel in the fuel pump arm. In the old days the pump arm moved back and forth a good half to one inch. My new Carter marine fuel pump for this 5.7L only moves maybe a quarter to 3/8 inch, is that normal for the newer mechanical fuel pumps? I do see in the manual that the fuel pump pushrod (5.75 inch with brass tip) movement is only 0.34 inch so I am guessing the new pumps don't require the travel distance of old school pumps. Can someone confirm before I bolt the pump into place? There seems to be little margin for error in the pushrod travel.

Thanks....

 

[Grub54891]

If the arms are the same, it should pump just fine. If the arms are slightly different, you have the wrong part.

 

[Scott Danforth]

the fuel pump cam lobe movement on a small block and big block hasn't changed since 1953 when the small block was being developed.

its about .375-.395 total lift

that is all it takes to pump fuel.

Ford used to have only 0.200" of lift on the old flat-heads, not until after the y-block did that increase to about .3"

 

[76SeaRay]

Grub, I don't have an old one to compare. This is a scratch build from bare block. Scott, thanks for the info. I sure thought they used to move more than that but it may be my covid brain fog..... Be glad when I fully recover...

 

[Scott Danforth]

sorry to hear about covid.

your building from scratch and didnt go stroker?

 

[76SeaRay]

No, this is just a cruising boat with some fishing to be done. I don't want to overpower Alpha One and, as set up, it should come in right about 300hp. I went with roller cam and lifters with the Xtreme Marine XM264HR cam. That gives a bit more lift.

 

[Scott Danforth]

Properly set up, a 5.7 with that cam is about 330hp at flyweel, about 300 at prop