Electric fuel pumps

[Guest]

My camshaft finally wore to the point that a mechanical pump would not supply gas to my carb. I was stranded 250 miles from home so I bought a Carter P4259 HI-Performance electric fuel pump (vane type). Just to be able to get home I installed it on the side of the engine where the old pump went. It works wonderful and my car runs better than for a long time.

The instructions say the pump should be mounted almost even with the gas tank and within a foot of it. Apparently they are designed to push rather than suck. Where mine is mounted it is eigtht feet by pipe from the tank and low enough that the fuel will run down the pipe to the pump. I have been told that doing it this way the pump will not last three months. That it has to be mounted at the rear. I could do that but it would involve quite a bit of work to make a bracket to fit inside the frame and miss the shock arm, tailpipe, spring shackle and have it low enought o miss the floor boards. Do any of you have any suggestions or experience with one of these???

Thanks in advance.

[Joe Block]

MY guess is your Ok as long as you ave a good gravity feed. The new Godge Ram Diesel 19988-2002 have the electric pump mounted high on the engine and they to get starved for fuel and wear out, but we still talking several years most of the time and rigs with oversize fuel injectors.

My electric wnt in by the tanks as it was the easiest place to access in the garage of the auto parts store the day the other pump when out some 15 years ago. Still running on the electric.

[Guest De Soto Frank]

Well, you could always cabbage-up a Stewart vacuum-tank... <img src="http://forums.aaca.org/images/graemlins/crazy.gif" alt="" />

[Mark Shaw]

I used to sell pumps, & I can assure you that there are good reasons why you should locate the pump close to the tank.

Gasoline is a relatively low vapor pressure liquid. When the pump reduces the pressure in a long line to "pull" the gasoline, it can cause small bubbles to form that will cavitate (implode or collapse)inside the pump. This will damage the impeller, shaft seals, etc.

Longer fuel line means more cavitation and increased probability of "vapor lock" on a hot day. As the gasoline temperature increases, the vapor pressure is further reduced and is more prone to these problems.

If you cannot locate the pump close to the tank, increase the diameter of the fuel line between the tank and the pump.

[Guest]

Thank you for your replies. Sometimes it seems allmost impossible to find out "WHY" something should or should not be used. I seriously considered and still think I might attempt to make (from scratch) a vacuum tank. It certainly is not rocket science.