Jusat freshened the motor in my 91Z it has the 5.7 liter and an auto tranny...Here goes the problem..Ran the valves....started the motor....oil pressure is reading about 15 psi on the gauge....look at the oils squirters on the rockers and they are just dribbling oil out not spitting it everywhere like they are supposed to...so i kill it and start to look for problems...cant find any...so here I am...Only thing i can think is a bad or weak oil pump..I pulled the motor and I replaced the pump but would like to test the oil pressure prior to reinstallation so im not jerking it again if this aint the problem...any ideas on how to test outside the vechicle and also other ideas on if its not the pump..(plugged oil galley) would be great.
TIA
Chris

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Purple 91 Z28
LB9 305 TPI
5 Speed
Power everything
Daily driver

Red 91 Z28
B2L 350 TPI
G92 car
Auto
Power everything
SLP 1 3/4 headers
currently under going a complete makeover

 

buy a oil pump primeing tool. it'll spin the oil pump and you can see it oil the rockers, screw a gauge in the block and you can read oil preasure.

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-=ICON MOTORSPORTS=-

 

2/91s,

To add to Ed's thought, it takes a pretty good drill motor to turn the oil pump for any length of time without burning up. A ½" drill is probably better than a 3/8", and if you can vary the speed to about 400 RPM, that would simulate an 800 RPM engine idle speed. Whatever the engine would hold at that drill speed would be a close approximation of the actual idle oil pressure. The actual idle pressure would be lower due to warmer oil, and all of the lifters moving/pumping oil to the valves on every couple of revs. You could possibly have a cam or crank main bearing installed incorrectly, or a problem with an oil gallery plug at the ends of the cam gallery or between the rear main and the filter adapter ports.

Incidentally, 15 PSIG cold oil pressure is a little low, depending on the viscosity of the oil you are using. As a general rule, 5 PSIG per hundred RPM engine speed is adequate with warm SAE 20W (ISO 68) oil, up to the point of the pressure relief valve opening. Many engines operate lower than that, and have "acceptable" pressure. An engine with fresh bearings should be closer to the rule. The newer engines with the stepped oil relief (another rotton freakin' economy idea) are not covered by this rule of thumb.

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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0

[This message has been edited by Vader (edited October 22, 2000).]

 

Thanks for the help guys gonna try to spin it up tonight maybe ill luck out and not have to pull the crank to clean out the oil galleies...i'm fairly sure its the oil pump though

------------------
Purple 91 Z28
LB9 305 TPI
5 Speed
Power everything
Daily driver

Red 91 Z28
B2L 350 TPI
G92 car
Auto
Power everything
SLP 1 3/4 headers
currently under going a complete makeover

 

Did you have the cam bearings replaced? I once saw a SBC that didn't have oil pressure because the rear cam bearing wasn't installed properly. Cut off the supply of oil to the gage and rest of the engine.

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82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.