holley 715

[Dan Case]

Anthony
Since Holley missed putting in the fuel bowl level inspection sight holes like most of their other fuel bowls, the fuel level in the center inlet (Holley's original term) "LeMans Bowls" is unfortunately trial and error for a particular set of circumstances. Variables of angle to the horizon (on engine), vehicle dynamics is use (chassis stiffness and wheel base affect how the car jostles around), acceleration capability, deceleration capability, cornering capability, steel versus elastomer tipped inlet needles, and fuel pressure can easily confound your efforts to determine what float settings work best.

Power valve ok? I have had brand new ones from Holley I threw in the trash because they were defective in some way. A leaking power valve dumps fuel all the time. You might want to make sure it is functioning correctly first. I have done just two carburetors for Ford guys this year and the valve that came in one kit was worthless.

If you are still having any of the problems I described you are most probably suffering a fuel level too high. High actual fuel level makes driving a car so afflicted miserable. Not knowing any specifics of your application I would recommend lowering the fuel level (raise distance between bowl roof and float top with bowl upside down) 1/32” on which ever chamber you think is having high fuel level. Did this solve the problem? Make any improvement? If not, make the same 1/32” change to the other bowl. Many times lowering the fuel level just 1/32” makes a big improvement all around. There have been cases where it took me 1/16” change to get into a sweat spot. If you have to go farther than 1/16” I would look for some other reason too much fuel is getting to the engine. (Found a small shaving of rubber hose in one ’67 390 GT Mustang needle and seat once. Found the pivot pin for one float had completely fallen out in an original 427 Cobra that needed attention after an engine fire. The engine had the 2-4V system. One pin fell out and all hell broke loose. It was a factory defect, the pin had never been staked in by Holley. The fact I found the Holley defect got the insurance company off the owner’s back. They thought he torched the car for the insurance.)

Dan