Holley fuel regulator adjustment

I recently purchased a Holley Blue fuel pump to replace the Facet cube I have on my Elva which has an MGA 1500 engine w/two HS6 SU's. The pump came with the 4.5-9 psi regulator which I have plumbed up to the carbs using a Y-block with a pressure guage installed in a 3rd-outlet.

I know that SU's supposedly like 2-4 psi but several folks have told me that they have had good results with this pump/regulator combo and have been able to adjust the regulator's flow down to 4.5 or so psi without any overpressure problems on their SU's, and that the high pressure regulator is better than the 1-4 psi Holley regulator. I hope I have made the right selection here. I'm using AN6 lines from the fuel cell to the regulator with a 3/8" nipple to the block and then 5/16" lines from the Y-block to the carbs,

In any case I am a bit confused by the Holley instructions which state:

"Any change made in fuel pressure will change the fuel bowl float level requirements. A readjustment in fuel bowl levels will be required for proper operation of the fuel system."

Assuming I am able to adjust the pressure down to where it does not overwhelm the needle valves in the float bowls I do not understand why I will need to adjust the float bowl level. I thought that on SU's that is pretty much a fixed thing.

Can someone shed some light here?

Thanks in advance--Michael Oritt

Well, I havent had any experience with Holley pumps, but it sounds like you need a different type of regulator. I would look for 3 -4 psi.

I installed the Holley Blue pump and Holley low pressure (1-4 psi) regulator and pulled larger lines--3/8 versus 5/16--from the cell up to the regulator and through a Y-divider (with fuel pressure gauge mounted on it), then 5/16 up to the HS6's. After completing plumbing and wiring today I fired it off and adjusted the regulator to 3 psi at fast idle, then repeatedly revved to 5K. The fuel pressure stayed constant, the EGT guages looked even and there was no overflow from the bowls so I think I am good to go, or at least start.

Best--Michael Oritt
Elva Courier

Good to hear, Mike. Have fun at VIR. I expect to be back for the Gold Cup.

I have not yet fired up my car after installing the Holley Red, but hope to be finishing up the regulator and gauge setup this weekend or next. Then we will see but I don't foresee any issues.

Bubba Wrote: