FAQ |
Members List |
Social Groups |
Calendar |
Search |
Today's Posts |
#21
|
||||
|
||||
Quote:
i put a robmc on instead 550hp version ( i forgot i had the robmc,bought from a member here) That pump made a huge difference at the track. if you want the new one from butler 100shipped. lmk
__________________
72 Luxury Lemans nicely optioned |
#22
|
|||
|
|||
Quote:
There is no "excess pressure" to return to the tank, because the pump is incapable of producing "excess" pressure. A pump with a vapor return that produces 5 psi at the carb, would maybe produce 6 psi if the vapor return was blocked. The "return" is considered a "vapor return", readily passes fuel vapor, but is heavily restricted in terms of liquid fuel. The fitting in the pump probably has a .060 hole, or smaller, that the vapor squeezes through readily, but presents a restriction to the more-viscous liquid fuel. (Photo attached.) Internally, that "return" fitting probably has a stand-off tube that goes to the upper part of the fuel pump liquid chamber, where the vapor is more-likely to be (and the liquid fuel is less likely to be.) I saw photos of this stand-off tube in the last couple of months, but I don't remember which web site, or who posted 'em. Quote:
What's more important is that it would be a waste of time, money, effort, and enthusiasm to bother with the restriction and the vapor return on a PUSHER electric fuel pump. The whole reason to have a vapor return is that the engine driven fuel pump is 1) hot, 2) "sucking" (reduced pressure) on the fuel tube going back to the tank, and 3) that fuel plumbing may be getting heated by the exhaust system. All of those promote fuel boiling in the suction (reduced pressure) plumbing. The vapor return is a crutch to get rid of the vapor and prevent vapor lock. The pusher pump runs cooler, and doesn't "suck" on the warmer parts of the fuel plumbing; and the warmer sections of the plumbing are under higher pressure--so there's no vapor and no vapor lock. Last edited by Schurkey; 10-15-2022 at 11:30 PM. |
#23
|
||||
|
||||
Quote:
Mike |
Reply |
|
|