Pressure Regulator

[JJH]

Hey guys! I apologize for all the questions lately, but I'm trying to get everything ordered and settled away before I leave for school after Christmas. I am wondering the importance of a pressure regulator on an engine-driven fuel pump feeding a 4bbl? I rarely see regulators on any classics in my area, so I never thought it was necessary when I "finished" my build last year.

 

[67Dart273]

It normally should not be needed. The way a mechanical pump works is that the lever acting on the cam so to speak "cocks" the pump, and the spring in the pump actually pumps. When the thing brings up pressure, say, when idling, against a closed needle, the lever actually floats on the cam. In that regard they are self regulating

Sometimes you get one that is "hotter" and there seems to be a big problem with modern quality of needles and seats. The final issue is that gasohol boils easier and causes more flooding and vapor lock related problems

 

[JJH]

Okay! I didn't think it necessary with a stock style pump, after all they didn't have them from the factory but I just wanted to make sure! Thanks

 

[greymouser7]

i think i read here that some carbs want to see only 6 psi of pressure from the pump, suggesting that more pressure creates problems. I am ignorant as to the experience though. If I recall correctly, carter/edelbrock carburetors needed less than 7 psi -I COULD BE WRONG.