Fuel Pressure

nhramnl · 02-01-2018, 10:41 AM

Dean Oliver may respond on his own (if he sees this string), but he helped me overcome a problem I had with richness and smoke at idle and low speeds (e.g. driving around the pits). I checked and rechecked everything with my Q-Jet 305, including even fiddling around with various fuel pressure settings, and the problem would not go away. I called Dean and almost the first question he asked was "Which needle and seat is in the carb"? I told him it's the extra-super-big one that Edelbrock sells, and he told me to remove it and go to the next size smaller. His explanation was that there is so much fuel flow through the big Edelbrock needle and seat that the incoming fuel actually partially overcomes the ability of the needle to close completely, which functionally raises the float level and causes flooding. He also said that with any "normal" racing fuel pressure, the fuel enters the bowl so violently that it keeps the fuel in the bowl all "stirred-up". I changed to the smaller needle and seat and the condition is gone.

02-01-2018, 10:41 AM	#8
nhramnl Senior Member Join Date: Feb 2010 Posts: 507 Likes: 8 Liked 358 Times in 83 Posts	Re: Fuel Pressure Dean Oliver may respond on his own (if he sees this string), but he helped me overcome a problem I had with richness and smoke at idle and low speeds (e.g. driving around the pits). I checked and rechecked everything with my Q-Jet 305, including even fiddling around with various fuel pressure settings, and the problem would not go away. I called Dean and almost the first question he asked was "Which needle and seat is in the carb"? I told him it's the extra-super-big one that Edelbrock sells, and he told me to remove it and go to the next size smaller. His explanation was that there is so much fuel flow through the big Edelbrock needle and seat that the incoming fuel actually partially overcomes the ability of the needle to close completely, which functionally raises the float level and causes flooding. He also said that with any "normal" racing fuel pressure, the fuel enters the bowl so violently that it keeps the fuel in the bowl all "stirred-up". I changed to the smaller needle and seat and the condition is gone.