I finally got my engine to the point where I could prelube. While cranking the drill at approx 3000RPM, I am getting almost 80 PSI of oil pressure! Also, as I run the drill the engine gets harder to turn. I have two questions. Is this pressure excessive? This is a bone stock ZZ4, and I have Castrol 5W30 oil in it. Second question, is the engine being harder to turn due to the hydraulic roller lifters pumping up?

Thanks!

Tim; If you're really cranking the drill at 3000 rpm,that pressure sounds right for that speed on a cold engine.If you're referring to cranking the engine by hand,with the spark plugs in,it should actually be slightly easier to turn as it bleeds off more cylinder pressure,though hardly noticeable.If the plugs are out,you'll have slightly more resistance from increased spring pressure at the higher lift. Steve

Steve, thanks for the reply. I tried to search GMPP on the P/N listed for the ZZ4 oil pump so I could see the specs, but I didn't get any hits. I do have the plugs out, this mother is a bear to turn with them in, not immpossible just tough.

3000 RPM on the drill, which is 3000 RPM on the pump, is the equivalent of 6000 crank RPM. That's also a couple of horsepower it takes to drive an oil pump to that speed, especially with cold oil. How are you holding that drill still? I think that's enough power to pick me up off the floor and twirl me around instead of the primer.

Oil pressure with hot oil at cruising speed (2500-3000 RPM) should be around 55 psi in that motor. It'll go off the 80 psi scale with cold oil at a couple of hundred pump RPM.

Sounds to me like everything's OK, and it's time to quit messing around with the drill and get the motor in the car and running.

Originally posted by RB69SS396Conv:
Sounds to me like everything's OK, and it's time to quit messing around with the drill and get the motor in the car and running. Amen!!! I am more than ready. Saw a couple of pretty awsome Chevelles at Pacemaker Dragway in Mt Vernon, Ohio last night. One guy had a sharp 71 and he was running 6.25 1/8 mile times. Went to the semis in the Super Pro category.