Stumped on the Pumps

peter carroll · 11-18-2003, 07:17 PM

Hello all. I had a 914 parts car with a 13B conversion which I parted due to rust. I kept every thing I thought I would need for my 914 Subaru 6 conversion. The 13B car had two Facet electric fuel pumps running side by side in front of the gas tank----one into the other. Can someone tell me why this was done and if I should do it the same way with the Subaru conversion. Hope this makes sense. Thanks for the help. Pete Carroll Baltimore, Md.

Ron Meier · 11-18-2003, 07:34 PM

Somebody bought two and couldn't return one?

An electric pump is a "pusher" not a sucker (mechanical). Maybe he had one mounted in the rear and couldn't get sufficient fuel volume and thought that two were better than one and remounted them in the front.

Regardless, if you can't fuel a carbed engine with one, you've either got one hell of a fuel line restriction or a very poor pump. One should do the job.

Hey - I gave it my best!

M. Hendrix · 11-19-2003, 04:21 PM

There are cars that come with multiple pumps in series.

M

peter carroll · 11-19-2003, 06:35 PM

How should a pump connect if there are two lines coming out of the fuel tank? Pete

Ron Meier · 11-19-2003, 08:27 PM

On the 14, one line is suction (to the pump) and the other is return from the pump/fuel rail (excess pressure) to the tank. It was designed to keep fresh fuel in the fuel rail system on injected cars and prevent vapor lock. Of course Miles doesn't believe in fresh fuel

If your gonna run carbs - you only need one line. You can purchase a holley fuel pressure regulator and run a carbed engine like an injected engine (with a fuel loop). Carbs need only 3-4 psig, which is about what the FACET pump puts out. Anything over 5 will collapse the floats and cause flooding (can you say FIRE). If you run a high pressure pump, the excess pressure is bled back to the tank thru the return line.

There are diagrams somewhere on this site and in a Haynes Manual or ?

Race cars (which Miles doesn't have) will run multiple pumps because if one fails ya got another - this would be the only logical reason. That said, some cars will run multiple pumps - an "in tank pump" to get the fuel over the hump to feed another electric high pressure pump that feeds the engine - Can you say Volvo.

Damn, this is really to serious! I gotta go get a Billy Beer.

ruddyboys · 11-20-2003, 03:51 AM

Would there be any advantage if you have dual carbs to use the the two lines from the gas tank and run a pump to each carb?

M. Hendrix · 11-20-2003, 04:18 AM

Quote:

Originally posted by Ron Meier
Of course Miles doesn't believe in fresh fuel

Damn, this is really to serious! I gotta go get a Billy Beer.

Ohmahgod! AND I DO HAVE A RACE CAR! YOU'VE NEVER BEEN IN THE GEORGIA 400!

M

Ron Meier · 11-20-2003, 04:38 AM

Hmmmmm - the JawJa 400 - Is that the annual race to see who gets to the roadkill first?

In most fuel tanks, the suction line in the tank runs the depth of the tank and the return line is shorter - on a partial tank the carb running off the return would run out of fuel before the other.

M. Hendrix · 11-20-2003, 05:01 AM

Quote:

Originally posted by Ron Meier
on a partial tank the carb running off the return would run out of fuel before the other.

RESULTING IN A LEAN CONDITION.

M

Dave at Pelican Parts · Dave at Pelican Parts's Garage

Quote:

Originally posted by ruddyboys
Would there be any advantage if you have dual carbs to use the the two lines from the gas tank and run a pump to each carb?

No.

--DD