Return Flow to Prevent Regulator Creep?
09-28-2007, 05:46 PM
#1
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Return Flow to Prevent Regulator Creep?
When I turn on my electric fuel pump with the engine not running, my Holley regulator reads 6 psi on its regulated side. After 5 or 10 seconds or so, the regulated fuel pressure will slowly raise to 14+ psi (actually it pegs the fuel pressure gauge). When I start the engine, fuel pressure immediately drops back to the regulated 6 psi. I'd like to have the option to run the fuel pump with the engine off. I do have a capped off 1/4 inch outlet from the regulated side of the regulator. If I allowed some return fuel to the tank, I'm sure the creep problem will go away. However, the regulator has a 3/8" inlet port and if I bleed off fuel from a 1/4" return outlet, I'm concerned I'll bleed off so much fuel there won't be enough left for the carburetor. Does someone have some experience with how much bleed off return line fuel can be tolerated? How to restrict the return fuel line?
I have an Aeromotive fuel pump, near the fuel tank, that produces over 14 psi. The regulator is the "heritage" Holley regulator that they've been selling for 25 to 30 years. The Holley has one 3/8" inlet port and two 3/8 inch regulated output ports to feed the two Holleycarb bowls. My now capped off 1/4 inch return line is"T'd" off the 3/8" inch feed to front fuel bowl.
Thanks
I have an Aeromotive fuel pump, near the fuel tank, that produces over 14 psi. The regulator is the "heritage" Holley regulator that they've been selling for 25 to 30 years. The Holley has one 3/8" inlet port and two 3/8 inch regulated output ports to feed the two Holleycarb bowls. My now capped off 1/4 inch return line is"T'd" off the 3/8" inch feed to front fuel bowl.
Thanks
09-30-2007, 10:44 PM
#3
Race Director
Those Holley regulators are advertised to work without a return but they really don't, if at all for very long.
Best is to use the unused port off the regulator.
The return line has no real resistance so, it should then stay at wherever you set it.
I started just making my own such as your tee'd carb line.
I use a oriface in the fitting with a hole size of around .035" to keep the carb supply at around 4psi.
An easy way is to tap the inside of the return line fitting to accept a carb jet (or any threaded plug) and either change jet sizes to suit or drill bigger. If you screw up then just replace with a new jet.
Most people tend to run too much pressure anyway. Run the least amount you can without susatined rpm at WOT.
Best is to use the unused port off the regulator.
The return line has no real resistance so, it should then stay at wherever you set it.
I started just making my own such as your tee'd carb line.
I use a oriface in the fitting with a hole size of around .035" to keep the carb supply at around 4psi.
An easy way is to tap the inside of the return line fitting to accept a carb jet (or any threaded plug) and either change jet sizes to suit or drill bigger. If you screw up then just replace with a new jet.
Most people tend to run too much pressure anyway. Run the least amount you can without susatined rpm at WOT.
10-01-2007, 01:07 PM
#4
Team Owner
Thread Starter
Member Since: Jul 2004
Location: Redondo Beach, California
Posts: 39,526
Received 546 Likes
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374 Posts
Those Holley regulators are advertised to work without a return but they really don't, if at all for very long.
An easy way is to tap the inside of the return line fitting to accept a carb jet (or any threaded plug) and either change jet sizes to suit or drill bigger. If you screw up then just replace with a new jet.
Most people tend to run too much pressure anyway. Run the least amount you can without susatined rpm at WOT.
An easy way is to tap the inside of the return line fitting to accept a carb jet (or any threaded plug) and either change jet sizes to suit or drill bigger. If you screw up then just replace with a new jet.
Most people tend to run too much pressure anyway. Run the least amount you can without susatined rpm at WOT.
Hal
