The Stovebolt Site Forums The Shop Area Engine Shop reducing fuel pump pressure

I have a stock fuel pump on my 37 Chev 1/2 ton truck with a stromberg BXOV2 Carb. I want to reduce the pressure from the pump to about 2 1/2 pounds but dont really want to put in a fuel regulator

I heard somewhere that if you pack out the fuel pump from the engine block this reduces the stroke on the mechanical lever therefore the fuel pressure.

Has any one heard of this before?

PS have attached a link to a recent photo of my truck

http://s1260.photobucket.com/user/37Chev/media/Truck/20150607_142954-1_zpsubj05cyr.jpg.html

I have never heard of that but I don't think it would work. It would reduce the volume but I dought if it would reduce the pressure.

Thanks wrenchbener the guy who reconditioned the pump said the same thing just wanted to confirm with the experts

You need something like this, http://www.mamotorworks.com/vw/Prod...m-glass-filter-bowl-made-in-italy_319758 , it looks like it would belong on the truck.

This place has one in the works, http://vintagespeed.com

You can use a modern type and mount it back under the cab. Run your normal line from pump up to carb (s), then " T " off it with a line running back towards the firewall, route this line down and back to the tank. Install the regulator out of site, then dump the excess fuel back into the tank or fuel line. The carb (s) will receive full volume of fuel at the regulator pressure. Dirt racers run fuel systems this way. If you regulate before the carbs, you receive reduced pressure and reduced volume. It also keeps electric fuel cool since fuel is always moving through them.

Joe

Joe H,

Nice links. Thanks for posting them. It would be interesting know if that Edmunds reproduction is being made. The European one looks "period correct" (but, a little "pricey" - around $100).

I have used this less-expensive style but have had to send a few back, probably dried-out diaphragms (that the sellers blamed on bad gas - maybe/maybe-not).

To change output pressure of a mechanical pump the control point for the pressure is the diaphragm spring. If you have a pump that you can take apart and tweek the diaphragm spring pressure you can lower the output.

"The pressure at which the fuel is expelled from the pump is thus limited (and therefore regulated) by the force applied by the diaphragm spring."

A secondary point is the output port opening size on the pump, but much more difficult to work...