SW 240A Fuel Pumps

[FatBoy]

Originally Posted by A98Coupe

I must correct you all on this topic. The SWs are connected in parallel according to SW's 'Stand-By Installation' instructions. This means only one pump runs while the other is on stand-by should the other pump fail during racing. Both pumps take their feed from the bottom port in the tank and both pumps feed into one 3/8" fuel hose which in turn feeds the mechanical fuel pump. The SW pumps act purely as booster for the mechanical pump so that the 427 does not suffer fuel starvation during sustained high rpm running. This arrangment is clearly shown and described in the SW 240 series installation instructions.
They are operated by a single pole, double throw switch with a current rating of at least 15 amps.
The port higher up in the tank is purely for a fuel return line for competition cars fitted with a fuel pressure regulator.
The 'urban myth' describing the SW pumps as a reserve tank feed when the fuel tank was low is simply wrong. The 427 Cobra was intended to be a race car and it needed the SW booster pumps mounted near the fuel tank and running constantly to ensure the mechanical pump had sufficient pressure & flow at all times during racing.

Thanks Stuart, that makes much more sense to me and I was going to suggest that the higher "pickup" in the tank may actually be a return.

Paul