MG Sports Cars

I was browsing the latest Jegs catalog yesterday and noticed a Holley fuel pump I'd not been aware of. Apparently in May this year Holley introduced a new line of both 25 and 32 GPH, 4-7 PSI, fuel pumps. They are called Mighty Mites. The Holley literature claims they are quiet and will last years. They are self priming, small, and cost just $47.
I would be interested to know if anyone here has any first hand experience with one.

Steve

Sounds like what I need instead of my noisy Carter!

Might want to check "actual" flow pressure.

With new engine (V-6) I struggled with serious lost of power and stumbling after each gear shift. The more I drove, the worse it became.

After adjusting floats on Holley 390 2-3 times, timing, plugs, carb adjustments, tuning with a vacum gauge, and consulting with so-called local experts... I actually broke down and read manuals on the 390s. Took me several reads before I saw the obvious! Holleys don't like fuel pressure above +\- 6 lbs.

Put the pressure gauge on fuel line and found 7-8 lbs at the carb. I put together a cheap guage and flow regulator from O'Rileys and cranked it down to 5.5-6 lbs and all is well!

The stumbling I interperted as fuel starvation was actually (apparently) too much pressure driving the floats/needle valves up and sticking.

My fuel pump was new ( Micro Electric 12-S from Mr. Gasket) and said 6 lbs output... but....

So I have no knowledge of your specific pump but I'd sure check what it is really producing after installation.

Don B.

Apparently Edlebrock carbs feel the same way about pressure. Holley has a 4 psi/ 25 gpm and a 7 psi/32 gpm Mighty Mite pump; I have a Edelbrock 600 cfm carb. The Edelbrock's manual recommends 5.5 psi at idle but no more than 6.0 psi. I'm guessing the 4.0 would be sufficient at idle but at WOT will it drop off to much? The 7.0 with a pressure regulator would be ok but more components a system has isn't always better. Thoughts?


Paul

To add to the fuel pressure/volume discussion,
Both Holley and Edelbrock offer a variety of different sized needle and seat assys.
Most of the originals are Viton tipped and work well. But the new "enriched" fuels can attack the needle tip and cause problems.
Steel tipped assy's are available to fix that issue.
The aftermarket (offshore) ones should be avoided like an ex wife.
What you want to do is use the smallest unit that will supply enough fuel at WOT.
The smaller valves are far less sensitive to fuel pressure variations. And will control the fuel level better.
Using a valve that is too large can also cause flooding on a hot start. And as Don found, hard to diagnose overfueling.
I'm all for a pressure regulator. It takes most of the variables out of the supply pressure system.
Just make sure to use a bypass type regulator. The deadhead styles just let the fuel cook in the line and pump. Which is exactly what your non regulated electric pump does. It just circulates fuel around in the pump until it's needed, heating it considerably.
Using a proper return system with a bypass regulator fixes all of that.

Cheers
Fred