normal fuel pressure

HI,
I was just wondering whats the normal fuel pressure for a 450 hp big block being street driven?

thanx

With mechiancal pump 6-7 psi will due

how bout electrical? I am running about 5 and some people tell me its too high.

With a carb in decent condition, 5 PSIG is just fine.

well im trying to eliminate reasons im getting fuel in my oil pan, and im thinking about just rebuilding the whole engine due to how much fuel i think has gone through the engine and low vacuum, but want to make sure i can rule out fuel pressure as a cause.


tahnx

wait, what? Sorry, i probly wasnt that clear, or i am confused.

My manifold vacuum is low, and then i was talking about my fuel pressure as well. I included the vacuum part just cuz i dont know if that could be part of the fuel problem as well.
Maybe you can clear me up on it if im wrong or making a fool out of myself.

thanx

ok. sorry ahead of time if we have gone over some of this before, but i have had down to a 2.5 power valve in it. I dont know what power valves were in when i checked the vacuum, but it was only at 5hg in gear. The fuel pump is electric so that rules out the bad diaphram right? i have only gone down a few jet sizes but maybe more are needed?

thanx

the jet have nothing to do with the idle. if smell rich at idle a then it has junk in the air bleeds or the idle screws are out to far or the front or back power valve is shot or is not the right one if there is gas in the pan then i would say there may be junk in the neelde and seats .why not try a different carb

well i first had a 1050 dominator on, and that was fine at sea level. Then when i moved a switched to a 4150 hp 750cfm racing carb. And now im at a 770cfm street avenger and still having same results.

5 psi is not good enough for the 1050 plug the power valves and go up 10 jets sizes up and try that. i do not run power valves at all in cars that have less that 5 inchs of vacuum in gear. look at the gas regulator i have had many 1050 and 1150 and they did not have power valves. runed them on the street

when i still had the 1050 on i did have the block off power valves installed and it was fine at the sea level but when i brought it up to my 4000ft elevation and got fuel in the oil pan i said screw it and went with the 750 cuz i thought that the dominator was just too much carb. also, im running 8An line for my whole fuel line and have both lines in both bowls.
Another thing too, is the cam manufactorer said the cam should have 8-10" of vacuum in gear. Is that a big thing to worry about?

Thank you guys for keeping with me on this.

I know that part but i just dont know how to achive it. fuel pressure? jets?

thanx

ok, and what would be jetting down too far?

thanx

sorry, i didnt write my question right. Like how many jet sizes down would be too much. Like lets say i jetted down like 10 jet sizes and still had a problem. What would that mean?

I really appreciate your help!
thanx

ok. well the jetting was at 75 secondary and 72 primary. I brought it down to 70 secondary and 65 primary and i heard a ringing but i think that was something on the truck. anyways, it was blowing white smoke all over and still had STRONG fumes of gas.
Any other advise?

air bleeds

ok. i will check them. could they be too big too?

thanx

sounds like you have more than one thing going on .but i would do what i said plug the 750 power valves off and move up 5 jets sizes were you are now and try that. air bleeds should not be that far off ? but they maybe junk in them like i said you will have to do some of the things to find out

hey pat,
Do you mean up 5 jets from stock jetting? The air bleeds checked out fine, so im thinking to rule that out.
When i was just running it too, i had a 2.5 power valve in there and it seemed to run pretty good with those lower jets except still the VERY strong gas smells which has been the problem anyways. and the white smoke scares me.
thanx for the help and ill try the blocking off once i hear back from ya.

yes go up five jets from stock if 750 i think they may be 72 ? or so 77-78 try that you want to dry it up and block the power valve up front and back if you have one you want two start with a base line and work up from there

one other question on this. The 770 i have is a vacuum secondary carb and was wondering how that works since the power valve is already blocked off and if it really would matter on jet sizes for the secondaries. Also, would it be better to use the vacuum secondary carb for this?

thanx and sorry for taking so long to resond.Was on vacation for bit.

thanx again