Right now all I have for a fuel pump in my car is one of those weak genertic $35 electric fuel pumps that you can buy at auto stores. I think it says 35 gph with 3-5 psi...Obviously this isnt enough to run my small block chevelle...What I'm thinkin is, since I have grown to love the electric fuel pump because of its ease to start engines with (always have fuel in the carb, eliminates cranking), I'm wondering if I were to get a mech fuel pump on there, but leave the electric one inline near the tankm would the electric one hinder the flow of the mech one? Could I run both at the same time for additional fuel flow? I'm thinkin of using the carter 172, but will it be too much for a small block? And will I need to run a regulator? This is with the stock tank, pickup, and lines.

thanks

graemlins/beers.gif

Ok, no one has answered, but I've changed my mind and am gunna go with the Carter 120 street pump. I still want to know if it is ok to have the electric pump inline at the tank and all that. graemlins/beers.gif

I run both pumps on my bracket car. The mechanical pump pulls fine through the electric pump for normal driving (I drove on the street for a couple years like this). I turn on the electric for WOT blast. The engine starves at WOT without the electric on. Too much of a restriction, I guess.

The Carter 172 will NOT be too much, it doesn't need a regulator and is an excellent pump in both Big and small block versions. it will simply bypass itself when the demand is lower. I would recommend using it and then if you don't maintain at leats 3 psi (too keep the bowls full) add an inexpensive electric like Pat said.

Keep in mind I experienced NO difference in performance from a Carter 172 dropping to 3 psi during a run and the electric mallory with a constant 6 to 6 1/2 psi.

I guess I didn't have one of those Mysterious high fuel demand camshafts that somehow know what the fuel flow is between the needle and seat and the pump even though the fuel bowl is full.

Well first off thanks for the replies.

I'm curious if my crappy auto store perfurator fuel pump will cause issues inline that maybe a good holley wouldnt.

Also, will I need a return line to the tank with the 172?

I'm havng trouble finding a price on a 172, summit or jegs doesnt seem to have it. I think for my application, if the 172 is too much more, then I'll go with the 120 street like I mentioned above. So I guess I need a price, and whether the 120 would ma needs as well as the 172. Very muchh appreciated! graemlins/beers.gif

The 172 has an inlet and an outlet, the bypass is internal...No return line. Summit and Jegs do not have them listed in the catalogs. The small block version part number is M60969 and CRT-M60969 in Summit for $74. You will need AN Fittings to attach to the fuel lines.

It is possible that the cheap electric pump could be an issue. With the Carter pump, just bypass the electric pump. I only use my electric (Holley red) while racing. If the diaphram in the mechanical pump should burst, the crankcase could be filled with gas. Not a good thing. I turn it on in the water box and off at the finish line.

Originally posted by Pat Kelley:
It is possible that the cheap electric pump could be an issue. With the Carter pump, just bypass the electric pump. I only use my electric (Holley red) while racing. If the diaphram in the mechanical pump should burst, the crankcase could be filled with gas. Not a good thing. I turn it on in the water box and off at the finish line. Yes, Thanks Pat, that is what I meant, Add it to the system, I wasn't completely clear. By inexpensive I was implying or referring to the Holley Red.