Mechanical fuel pump as a scavenger for an electric? plus other questions

Joined
Sep 20, 2005
Messages
1,998
Location
Los Gatos, California
With my big 49 gallon fuel tank, it is impossible to mount my fuel pump below the level of the tank.

Can I use the mechanical pump on my SBC 350 to feed my electric? seems like it is okay so long as the flow is there.

Which inline pump is the best? I have read the threads and looked online, I would like an Edlebrock quietflow, but it is $600 on Summit.

If I get a higher pressure electric pump, can I use a regulator with a return line? Are there any good 15 PSI pumps?

This is for TBI. Thanks:cheers:
 

Poser

Oh...Durka Durka Durka.
Supporting Vendor
Joined
Oct 1, 2003
Messages
20,456
Location
MN
So why would a mechanical pump pull fuel and an electrical one supposedly not?



There are many electrical and mechanical fuel pumps used on a variety of equipment where they are not mounted below the tank, but rather, many feet higher than the fuel pickup in the tank.




:beer:
 
Joined
May 10, 2005
Messages
266
Location
Utah
I kept my mechanical pump when I installed the electric for the TBI, don't really know why, but it works.
 
Joined
Apr 4, 2005
Messages
176
Location
Northwest
So why would a mechanical pump pull fuel and an electrical one supposedly not?



There are many electrical and mechanical fuel pumps used on a variety of equipment where they are not mounted below the tank, but rather, many feet higher than the fuel pickup in the tank.




:beer:

Because gear pumps are almost as bad as piston pumps for pulling a vacuum whereas diaghphram pumps aren't hurt by running dry and pull a larger vacuum per stroke.
 
Joined
Sep 20, 2005
Messages
1,998
Location
Los Gatos, California
So why would a mechanical pump pull fuel and an electrical one supposedly not?



There are many electrical and mechanical fuel pumps used on a variety of equipment where they are not mounted below the tank, but rather, many feet higher than the fuel pickup in the tank.




:beer:

I had always heard an electric fuel pump needed to be mounted below the level of the fuel tank. Right now I am using one very noisy electric pump. It gives me 11 psi and it is mounted about mid tank level. So far my only real issue is noise and pressure, however a couple times with only 5-6 gallons left the motor about cut out on the freeway............it definitely seemed like fuel starvation.
 
Joined
Feb 19, 2002
Messages
1,430
I was worried about starving my expensive electric pump also so I built a simple surge tank

I have been using a NAPA low pressure (for carbs) electric pump to keep it full. I was having problems with not maintaining pressure. I think it is because the NAPA pump can't provide the volume, so I am right now replacing it with a mechanical since my TBI block is machined for it. Stock GM pump delivers plenty of volume but only about 6 psi.

My TBI pump is a Walbro from Auto Performance Engineering, model GSL395. I can hear it prime itself but I can't hear it at all with the engine idling. Walbro has excellent specs and reputation.

Can't comment on how well this will work until next week, but I consider the surge tank a necessity since EFI pumps overheat quickly when you run them dry (so I've heard). This setup worked great for the first year or so. I just recently noticed the pressure problem and am in the middle of troubleshooting it. HTH
 

Users who are viewing this thread

Top Bottom