I've been thinking about instalilng an electric fuel pump in my 66 with dual quads. I suspect it might be a tad fuel starved at the end of the quarter. Any real world experience and/or advice out there?
FUEL PUMP Tom, I run electric pumps on most of my cars. I recommend running a bigger pump than you need and the using a fuel pressure regulator up front to knock the pressure down before going into the carbs. I run the noisy Holley blue pumps but they can be quieted some by using rubber insulators between the pump and the body and rubber insulated fuel line clamps. I would also run larger fuel line up to the regulator to keep fuel up front 'on reserve'. I have done this set up on many street cars, you can keep the stock pump if you want but it is not necessary.
Tom, what joe said is true, also mount it in the rear as near to the gas tank as you can. I really don't see how you have been running @ 4's with the stock pump. It had to be starving on the big end. J.T.
Thanks Thanks for your input. Funny, I was just talking to a guy at a cruise last night. He was strongly recommending that I just need a small (e.g. Carter) pump to supplement the mechanical pump. I was thinking of running a pump through the mechanical one, mounting it on the rear as you suggested with an oil pressure switch and relay for safety
I really don't know how well it works, to put an electric pump in-line with the mechanical pump. As I understand them, the mechanical pumps pump a rather high volume of fuel when needed. Because of the way they work, the pressure isn't really all that important. Therefore, if the mech. pump can't give enough volume, adding an inline electric pump isn't going to help all that much. It will slightly raise the inlet pressure to the fuel pump, however since the pump is limited in how much volume it can move, the extra inlet pressure won't do much good. The only time I heard of an electric pump being useful was when a guy ran his fuel line very close to his exhaust, and on hot days the fuel would vaporize in the line before it reached the mech pump- when he added the electric pump, the gas was under pressure and remained a liquid. But overall, he had other problems that had to he addressed, and the elec pump was just a bandaid. Now, that guy only uses a single Holley Red pump. They only last a few years, but otherwise they perform very well. -Bob Cunningham
I was told that you can use both mechanical and a electric pump together with no problem, if one gives out, you have a backup....JT
I picked up .5 with my dual quads just by running a Holley Blue pump and bigger line. The Holley pump pushed better than it pulls fuel- mout it towards the rear. I did run it through the mechanical fuel pump at first, but then deleted the mechnical. Here is why. If there is a failure with the mechanical diaphram the electric will continue to pump fuel, but now it will fill the crank case. The electric pump puts more stress on the diaphram as well. I have had the Holley stop on me a time or two from over heating the electric motor. The mouter would get hot and loose its proper tolerances and temporarily seize. The cuase of this is the lack of a return line or losts of slow speed or low fuel use. When the regulater dead-heads the pump the pressure pulse stalls or loads the holley and makes it work harder (pulls more amps) until the regulator opens up again. Everyone running a holley can hear it in the pitch (noise) of the pump when running. A return line would aleiviate this problem. I have meant to address this, but have not. Same pump has been in since 1996. :Brow:
I used a carter electric pump on a 401 with a holly 3 bbl [950 cfm] back in the seventys and never had any problems. Thier competition pump should feed 2/4s with no problems without the mech. pump. First put a good filter ,then the pump and if neccessary a pressure reg just ahead of the carbs. this set up lasted 13 yrs and was still working fine when I sold the car. Doc
I have a Holley Blue pump on my `67 also it is a bit noisy and i should install a return line but never get around to it,the thing i wanna ask is are the Holley blue pumps reliable enough for long trips? Thanks
When I started this thread, I wasn't having any problems with my mechanical fuel pump. I just thought that maybe it wasn't keeping up with the dual quads in the auarter mile and that the engine would benefit from some extra pressure during a race. I heard that they are noisy and, therefore I wasn't planning to replace the regular pump, just have a switch to turn on during actual runs. I figured it would also serve as a backup if the mechanical pump ever failed.
I wasn't trying to scare anyone from using a Holley Blue. They are reliable enough to be used on the street. Anytime I've had it overheat It would come back to life after about 10-20 minutes of waiting.Lone drives are probably not going to be the place where it'll quit anyway.
