Mech Fuel Pump Drag Racing 318
Here’s the things with mechanical fuel pumps.
They loose efficiency when they heat up. Adding a return line to the system is a very good idea. Mechanical or not.
Putting an electric pump before the mechanical pump is ensuring the mechanical pump always has fuel. The mechanical pump regulates the fuel amount and psi.
Should the electric pump fail, the mechanical pump will draw fuel through the failed electric pump at a lower rate than it would itself.
Sirelan67 posted a stock pump.
Not worthy for drag racing.
The previously mention Carter HP or race pump is OK for HP street machines. I run them on the regular. But they are not up to task for serious track efforts on a consistent basis. The Holley mechanical fuel pump is better, but still suffers from heat.
Ether way, a mechanical fuel pump will need to be cooled down between drag runs for best & peak operation.
To be honest here, plumbing in a regulator is easy. Running a return line when it’s not equipped on the car from the factory is a PIA. But it is worth the effort.