Moronic fuel pump question...

-
SoulSurvivor

SoulSurvivor

Well-Known Member
Joined
Jul 26, 2008
Messages
865
Reaction score
151
Location
SoCal
Hi gang,

I am ready to connect my new mechanical Holley fuel pump up. How can I tell which is the inlet or outlet on the pump? I am working on a new engine compartment so I am not just replacing a bad one. I forgot to take pictures, the pump came with no instructions, and I can't seem to find any info on the web. I should have asked here first. Please point me in the right direction and thanks!. Just a few more days until I fire up that new 340...
Doug
 
I believe the port on the bottom section is the inlet. If the pump isn't mounted to the engine yet, cycling the arm slightly could confirm or disprove what may be faulty recollection on my part.
 
The fuel pump inlet and outlet are parallel with each other. The pump is mounted on the engine. What would I look for to know which is the inlet?
 
well on my slant mech pump the one from the tank was just a nipple that u use a clamp on the hose from the solid line to the pump and the other should have a threaded female end for a fitting for the line that goes up to the carb.

hope this helps. and if there both the same. just put a line in a cup of gas and if nothing comes out switch the lines.
 
It says on the pump IIRC.

When mounted, ports pointing towards teh frame rail, rear leg is in, front leg is out... at least that's the way on my car before it died.

My experience with those pumps, it won't last long.
 
you could use a vacuum gauge on each port of the pump to determine the suction side of the pump while cranking the engine over.
 
Oops. I'd failed to consider the two types of pumps available.

If it's this one, I'm fairly certain that the lower port is the inlet
http://www.summitracing.com/parts/HLY-12-360-11/

If it's this one, I'm fairly certain that it's the port to the rear of the car
http://www.summitracing.com/parts/HLY-12-838/

Anyone have more concrete information whether supporting this or to the contrary? My Holley documentation is buried (if it hasn't been lost entirely over the past few moves).
 
Surely the easiest way would be to do what someone else here said...just hook a tube up to one port and put the tube in some petrol and manually crank it. I would definitely assume the port closest to the fuel tank (when bolted up) would be the inlet so try that side first. The port facing towards the front of the car i would assume to be to the carb
 
I just put a holley mechanical pump in as well... mine also had no instructions but was marked on the underside of the pump.
 
Dart_440 said:
I just put a holley mechanical pump in as well... mine also had no instructions but was marked on the underside of the pump.
Click to expand...
Bingo. There is an arrow marking the 'out' on one of the connections.

Thanks for the tip.
 
You must log in or register to reply here.
-

Back
Top