Fuel pressure regulator

[Jake S.]

I believe so. The lift/electric pump just has to provide a constant supply of low pressure to feed the transfer pump. Anything higher than stock might/would play with timing. I have heard the the transfer pump psi is something like 40-75. There is a port/screw on top of the nosecone where a guy could check it. Mel would know way more about it than me though.

 

[72f2504x4390]

I have a mallory pump on mine, 10psi. Didn't run right. I screwed in a holley regulator into the inlet side of the filter header, bent up a new line to connect to it, have it set at 4psi and it runs fine.

I did turn the pump down to about 7 and it ran fine without the regulator.

 

[Ironman03R]

So it sounds like 7 is the max and anything over that retards timing? or would it be advancing it?
Back to the whole IP timing thing...The way I understand it is the IP advances timing for low rpm then retards it at higher rpm? Or is it the other way? At what RPM does it change from advance to retard?

 

[Jake S.]

As the pressure in the IP rises (which follows RPM) timing advances. More RPM= more advance. The lever on the side retards timing. The more throttle, more retard. You can look at the cam and see that it only retards till 3/4 throttle or so. This simulates a curve similar to a gasser with vacuum advance distributor.

 

[ttman4]

Interesting about how these things don't run right with too much fuel pressure. I'd never thought about it like this.
Mel, sle2115, & you other guys have posted some stuff here that makes some things fall into place for me.

I had just figured that concerns about over 7psi pressure had more to do with blowing return lines loose & off, etc.
This brings my question. & I'm not going against "tried & true" methods & experience....I'm sticking with Red.
But I have wondered about volume of these Reds, Blue, Black, Mallorys, Carters, etc in relation to the pressure.

If for some reason someone running "offbreed & inconsistent fuels" like WVO & other narley stuff & wanted more return flow back to tank to help with fuel heat in tank, then running one of these higher pressured-higher volume electric pumps won't achieve much?

I guess what I'm trying to put into words is, let's say an elect. pump at 15# supply's too much press. for IP to handle. I got that.
But wouldn't the higher press.=higher volumn that's got to go somewhere.....back thru return? & overlooking injector orings leaking, return line connections, line size was big enough, & everything being equal & no leaks, wouldn't the extra press/fuel go on back thru returns?

Probably have to have a different way....partial IP bypass, to get extra fuel back thru return system.

Anyway, just been wondering for long time about this. Wondered about how much volumn a stock lift pump puts out at different RPM's also.

I'm supposed to help a friend work on & modify his fuel system. I may just undo his return & do some checking of return output at diff. rpms.....catch it in a bucket & time it. Then I'll know. Do it on his rig instead of mine & tell him "it's part of requirements of this job"