well my friend and i did it, we build a 420 hp 355 motor, with all the goodies, and its naturally aspirated, no NOS or blower. We have one problem. As soon as we start the camaro we look at the autometer gauge oil pressure, and it reads 23psi. when we raise the throttle the pressure goes high, when we let go of the throttle the pressure goes back down to 23psi. What could be wrong, Can something eternally be broken, he drove it and it runs fast as hell, but my idiot friend really didnt succeed in breaking the motor in, doing burnouts and launching hard the motor has about 200 miles in it. Could that be the case, even though the pressure is 23psi it sounds healthy. What could be the problem ???????????????????

 

i don't think you have a problem, that's about how the oil preasure should act.

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ICON Motorsports
1st & 3rd
MM Black Diamond 538 F&AM

 

Oil pressure is RPM-dependent. 23 at idle is more than adequate. Your pressure while revved up will be whatever the relief spring inside the oil pump is set at - 40, 60, 80, whatever. As soon as you come back down below 1200 or so oil pressure will drop back down. Totally normal.

Now take that thing to the track and tell us about the ETs at MPH numbers. Let's make sure you're getting all the ponies you paid (and sweated) for!

 

yeah dude thats fine, my friends 355 he built which has around 400 hp has a high volume oil pump and 7 qt pan and all that crap and he gets 25 psi at idle so thats fine

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89 Firebird Formula
5.0 TPI T-5 WS6 G92 dual cat exhaust 3.42 posi T-tops Grant signature series steering wheel (sweet), Kenwood head unit with Infinity speakers, Accel cap, rotor and wires, AC Rapidfire plugs, K&N Filter, Flowmaster 80 series muffler w/ full 3 inch exhaust, 180* stat, AFPR
New best run 14.8 @ 93mph

 

I personally wouldnet be staisfied with 23psi at idle. Is it warm or cold idle that it drops to 23? Some oil pumps come with the high pressure spring installed and some come with one as an option to install. Its possible the low pressure spring is installed. also if this pressure is what you had on inital startup when the engine had 0 miles, its possible the bearings are oversized thus reducing pressure.
Just througing out some possibilities although 23 is fine on a warm engine "idle".
SSC

 

hmm i thought 40psi was normal idling and running, guess it shows i dont know squat yet. We plan on taking it to the track but we have 2 problems. We installed a 9 bolt rearend from a trans am with disc brakes and a posi unit with an unfortunate 2:73 gear, we hope to order SLP's 3:73 gear and install a Mufflex system, we should be able to take it to the track in Englishtown NJ with in a week or two.

 

yeah, thats about right, I get 24psi, running on 430 hp natural aspiration.

 

Are you sure the SLP stuff is for 9-bolts?

IMHO 23psi idling is maybe a bit lower than most but still plenty. As long as it goes up to the 50ish range when it's above 1800 RPM or so, it's fine.

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"So many Mustangs, so little time..."
ICON Motorsports

 

Mine starts off around 40 psi until it gets warm... then it will drop to about 15psi at idle! It goes up pretty fast when I hit the gas. Pretty sure it isn't the new oil pressure gauge either because the old one did it too...

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1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock with the exception of the Holley 750vac... all the suspension stuff... 9-bolt posi disk is in...

-=ICON Motorsports=-

 

great thanks guys, i know that SLP is the only company that makes rearend gears for the 9 bolt,

 

I've heard you need 10 psi for every 1000 rpm.

 

I agree with the 10psi for every 1000rpm. 23 may sound low, but it is more than adequate. Don't worry about the breakin period, well, worry about doing it, but if he cracks into it a couple times, it should be okay. I nailed 6800rpm the other day, and have less than 50 miles. My foot cramped and I missed a gear. I may regret it in about 30,000 miles.



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Joshua Johnston
1991 Z-28


350, T-5, K&N, Ported Vortec heads, Edelbrock RPM, Holley 750 D.P., HEI, 11.07:1 CR, Comp Cams Roller-.510"/.520"-282*/288* dur., Shorty Headers, Dual 2.5 Exhaust,Dynomax Bullet Mufflers, T&R Motorsports custom air intake

 

Man, my 355 is 55 at warm idle and 70 above 1000 rpm.