I've had this problem for a while now. 355 sbc, mild cam, dart heads. Holly 'red' elec. fuel pump and Holly regulator. Set the Holly 3310 750 to the bottom of the sight hole threads. HUGE bog and lotsa raw gas smell out the exhaust. Had HEI curved/rebuilt, no diff. Timing....yadayada, no diff. Even put on a new 670 avenger, no help.
Well I checked the fuel pressure yesterday and it was a measly 3 psi. Bypassed the reg and got an even 6 psi. Adjusted the reg to 6 psi, took out the sight plugs and flipped on the pump. Christ, fuel spraying everywhere out the plugs! Reset the float level, so now at 6 psi the fuel is at the bottom of the sight holes. Been raining for six weeks now so haven't had it out. Can someone 'splain how the original 3 psi could have an effect on the float level? Could this have fixed the problem? I'm confused...

 

i don't see how increasing the fuel pressure could help your situtation.....the float chamber acts just like the back of the toilet bowl....and the float, needle and valve act like the ball plunger or flap valve in the toilet.....as long as there is enough pressure to make the gas flow into the float chamber and as long as the pressure isn't so great that it pushes the float down and puts too much gas in you are ok.....so it sounds like the 3 lbs of pressure met all of your needs an supplied enough gas to keep the float chambers full of gas.... the 6 lbs may equally work as well but i don't see how you have fixed your "gas smell"

 

Thanks for the response bro, my thoughts were that the lower fuel pressure was not allowing enough pressure on the needle and seat to keep it closed. The float level was adjusted properly with the lwr psi. When double the psi was introduced I had fuel rolling out of the sight holes until I lowered the floats (1/2 to 1 turn). I know it sounds wierd but it's the only thing I can come up with.

 

that sounds like the reverse of whats happening....the needle and seat are what limit and cut off the fuel supply coming in.....the float is what rises and holds the needle closed.....too much fuel pressure will actually push the needle in and submerge the float

 

Well...poop! I'm gonna go fire the darn thing up in the garage (doors open) and see if it helped at all.

 

Power valve?

 

I thought the Red Holley pump did not require a regulator.

 

I can't explain ur fuel bowl problems Dave but since i installed a recirc from carb to tank my Carter mech pmp (street series) works great by itself regulating between 6-9psi. U can see the pix in my profile links of the Tee i made at the Qjet inlet - removed filter, drilled, taped, JB weld brass bushing (and installed a small Holley inline filter). Also installed a Holley electric fuel press gauge with sensor at that Tee and can now read fuel press where my clock used to sit. No vapor lock to worry 'bout with a continuous flow sys.
The stock fuel pumps are self regulating and work great with a little constant flow of the recirc. Yea i never had luck with any aftermarket regulator as they don't like to control press once the inlet needle seats and the fuel line becomes dead headed - no internal relieve/bypass. Aftermarket reg's might work with a small recirc too but what the heck as the mech pmp has an internal one and any inline regulator will just add more restriction.
1 trick to use is a small orifice to limit return flow - i used 'bout .050".
Now u do need to run a vented tank system as i found out the hard way that with an unvented tank once u fill up the gas tank u will fill up the EVC.

U could just as easily install a recirc with ur existing electric pump too for a try and should work just as well. BTW lar's has a great write-up somewhere (on the corvette facts forum i think) on how to make a recirc for a double inlet Holley/Demon and bend tube & double flares too.

Good luck and i hope this can help or at least let us know if it don't.
cardo0