Why A Mechanical and Electric Fuel Pump Together?

[Bird 426]

What am I looking for a check valve ? My car has a Carter, and would like to also use a mechanical.

 

[Fran Blacker]

You need 2 tees, one side goes through pump. The other side goes through check valve. The check valve should be set so it only allows fuel to come OUT of tank.

 

[Bird 426]

Think that when I do this, I will just install a Facet pump like the one that was on my airplane. It allowed fuel to pass when off.
Thank you!

 

[dadsbee]

Think that when I do this, I will just install a Facet pump like the one that was on my airplane. It allowed fuel to pass when off.
Thank you!

At least when it fails internally you can just coast off to the side of the road. Not like my customer with the last Rebel that I sold. Facet popped the breaker and the engine quit about 40 seconds later in cruise. Thankfully on floats over the water. He'd forgot to turn it off after take off and was just cruising along. Glad it died where it did, he made a guys dock and after talking to me on the phone moved the fuel hoses to direct gravity feed and carried on home.

When the pump motor failed it jammed the pump internals shut.

 

[Bird 426]

Trust me, I know about fuel pump failure! Take off, had just climbed to 3,500 feet, shut boost pump off. A few seconds later, everything gets quiet, WTF! I looked back over my right shoulder, can I make runway 05? Get on the radio while pushing and right turn. Trying to do several things at the same time, what was the last thing you did? I look at the fuel pressure gauge, 0, flipped the boost pump back on. Seems like an hour before the wind milling engine caught, realize that the mechanical fuel pump has failed. Has the diaphragm failed and throwing fuel out the vent tube, which ends up in the area of the exhaust? I got lucky. Pucker factor............ Yeah, you can pull a car over to the side of the road.! That same Facet electric pump is still in the plane.

 

[Davefinan]

Trust me, I know about fuel pump failure! Take off, had just climbed to 3,500 feet, shut boost pump off. A few seconds later, everything gets quiet, WTF! I looked back over my right shoulder, can I make runway 05? Get on the radio while pushing and right turn. Trying to do several things at the same time, what was the last thing you did? I look at the fuel pressure gauge, 0, flipped the boost pump back on. Seems like an hour before the wind milling engine caught, realize that the mechanical fuel pump has failed. Has the diaphragm failed and throwing fuel out the vent tube, which ends up in the area of the exhaust? I got lucky. Pucker factor............ Yeah, you can pull a car over to the side of the road.! That same Facet electric pump is still in the plane.

WHOA….. I hope there was no leakage through the pucker.

 

[Dodge Bros]

Dang! Having something happen in an airplane thousands of feet off the ground is all kinds of scarry!

On a car with a mechanical and electric pusher pump that you need the fuel pressure only for wide open bursts you can wire in a WOT switch. The electric pump rarely runs then, no worries about the electric pump feeding a fire in an accident, and the mechanical pump keeps it primed.

 

[Bird 426]

I believe things were sealed pretty good, considering!

 

[Moparfever65]

I don't remember for sure, but either Carter or Mopar Performance used to promote this as a system, mechanical and electric pumps in series. There wasn't anything special about the pump, just their standard ones. I have this setup on mine.