Wondering what went wrong and what to do next?
Just got done rebuilding my new to me 302. Which included the following: replaced the main bearing ,rod bearings new cam and lifters[Edelbrock], new double roller timing chain, new pertronix distributor and new coil. Used my old heads off of my previous 302 [the valves look fine]. A Edelbrock alumin intake, and a brand new oil pump. Running the stock Motorcraft 2bbl Carb. So finally installed the motor last weekend got everything plumed and wired back to normal, hooked up the exhaust charged the battery. Then primed the motor with a old dizzy shaft. Guage read 40psi then put the dizzy in and fired her up for the first time. Took a while to get fuel pumping again[had to pressurize the gas tank]. Once she fired had good oil pressure, was off a tooth on the dizzy so took it out then re installed. started up again still was running rough tryed to time it a little faster that did'nt work then, i started hearing ticking like the rocker arms were all loose, so turned it off poped off the valve covers and noticed that number 4 exhaust valve rocker arm had fallen off! ... So went thru all of the rocker arms re-tighting them put the covers back on the fired the motor again. Ran a little better still pretty rough, then lost oil pressure and lifter noise started coming back.. looked at the oil guage had 7pounds of pressure at idle 750 rpm brought the RPM's up to 2,500 to 2,700 and the guage read 12 psi turned the motor off. Not knowing what to do next, I pulled the dizzy put the drill and old dizzy shaft back on the oil pump and the guage read 40psi again............ What happned? did i loose a main bearing??? Is one of the oil galleys blocked ????

At this point pretty bummed out with the whole thing. Just looking for some info on what i did wrong, or what to check next. .

Any ideas guys??

Thank you Matt.

Might just be a problem with the gauge. A mechanical gauge is less likely to lie to you.

i put in a new mechinal guage last year.

What i dont get is when the motor is running the guage reads very little to none, for oil pressure when i put the drill on the oil pump shaft it reads fine 40psi.

Try pulling your valve covers and run the pump with your drill to verify oil is pumped through the push rods. A static engine offer no resistance from the valve train. If you have good oiling with the drill try running the engine to see if you still have flow.

Just pulled the oil pan Very very dirty oil almost brown in color. No metal tho, thats a relief.! going to pull the oil pump tomorrow to see if its good or not. Horseplay i will try that as soon as it's back together.
Thank you Matt

by any chance did you replaced the cam bearings too? Had an old truck replaced the cam and ran good until it got to operating temp then lost oil psi, also check the oil pump drive rod and check if the splines are worn. man this sucks hope you can figure it out.

no i did not replace the cam bearing now im wishing i had.

My original engine had low oil pressure, when I yanked the pan I found cam bearing slivers sitting in the oil.

The motor is getting pulled out ethier this weekend or next ,and new cam bearing are on order