How much fuel pressure?

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doogievlg

doogievlg

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I am preparing to put a whole new fuel system in my car from the tank to the carb. I was talking to someone at the race track and they said to put a guage on it and see if I am at 6 psi. Does this sound like a reasonable number for a small block? Also if I was to go to an electric pump which one would you guys recommend?

360 .30 over
Speed pro flat tops
Aluminum heads
Performer rpm intake
Mopar electronic ignition
Holley 750 carb and Eddie 650 avs
 
i run about 6.5psi as for an electric pump http://www.gsl392.com/ this one is very quiet cheap and very durable and will support 600hp. to run this pump you will need to run a return line and a bypass regulator . the 392 pump is very famous with the turbo crowd as you can stack them. there is also a carb style that runs at 14psi this can be run with a deadhead regulator but is not recommended .a return line should be run with any e.p. to reduce heat and strain on pump and vapour lock . this set up will produce rock solid fuel pressure. if you want to know how i ran my return line let me know
 
my 1967 dart, charger factory service manual. 6 cyl pump model ms-3674s 3 - 1/2 to 5 psi. V8 273 - 318, pump model ms-3962 5 to 7 psi. V8 383-426-440, pump model ms-3672s 3-1/2 to 5 psi. all are carter brand.
 
Would the pump pressure depend on fuel line size? I have a 1/2" fuel line on my 414" stroker. Had it at 7 psi. Ran rough at idle so I dropped ithe pressure down to 5.5 psi. Idles a helluva lot smoother now. I have a Mallory 140 electric pump.
 
7 psi Holley, 4-5 Carter AFB. Everything else, I dont know.....çept my beater 82 Mazda truck, itls like 4 out of the original Facet jiggler electric.
 
I set my holley blue pump up at 6 1/4 ish PSI, straight thru no return, we have run up to 750 HP motors @ 6.5 PSI butttttt this is only for 1/8th mile runs.
 
Where do you guys mount your pumps? I am keeping the stock tank and was thinking about somewhere low in the engine bay.
 
doogievlg said:
Where do you guys mount your pumps? I am keeping the stock tank and was thinking about somewhere low in the engine bay.
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As close to the gas tank as possible....most electric pumps push better than they pull. If possible, get it low enough so it can be gravity fed from the tank. I have my Holley black pump on the rear fram rail, about a foot away from my cell.
 
jimjimjimmy said:
i run about 6.5psi as for an electric pump http://www.gsl392.com/ this one is very quiet cheap and very durable and will support 600hp. to run this pump you will need to run a return line and a bypass regulator . the 392 pump is very famous with the turbo crowd as you can stack them. there is also a carb style that runs at 14psi this can be run with a deadhead regulator but is not recommended .a return line should be run with any e.p. to reduce heat and strain on pump and vapour lock . this set up will produce rock solid fuel pressure. if you want to know how i ran my return line let me know
Click to expand...

I run 8 psi on an Aeromotive SS canister style pump and with a bypass setup (was intending on going E85 eventually). If I had it to do all over again, I'd use one or two of those Walbro pumps just because of the pump noise.
 
Well the guage said seven pounds so the pump isn't the problem. Plugs all looked great. But I put a new set in gapped at .45. It still seemed to miss but I couldn't drive it today so it's hard to tell. I put a new rotor cap on it just to be safe. Tomorrow it's supposed to dry up so I'll take it for a spin and if it does it again I'm putting the Holley on to see how it does. The next step will be a new ignition I guess.
 
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