Oil priming new long block question.

[rbail1]

1994 GMC C1500 4.3LTR Vortec TBI. Reman. engine block. Trying to prime the engine. With GM priming tool and my drill I am getting 40psi. Had to run the drill for like five minutes to get any oil on the top end. Oil started dripping out of the lifters one by one with a good five minutes between the first and the last to show oil. Is this normal? Not a whole bunch of oil. I would expect that once I had oil at all of the lifters that oil would start flowing or even squirting pretty good. Didn't happen. My max RPM on the drill is 1600. Seems that should be sufficient to get decent oil flow. Ideas anyone???? Pickup tube is set 1/4 inch from bottom of pan. Knowing that I have oil on top end now should I try cranking the engine without spark to see if that improves? Really don't want to undo all the work I just did by starving this thing of oil.

[Jsdirt]

I'd say it's normal, especially if you installed the oil filter bone dry. Got to figure every single lifter, passageway, and valley is bone dry too on a new engine.Even a well used engine takes about 2 minutes to see oil out of the pushrods at idle speed.

 

1,600 RPM on the drill = 3,200 engine RPM, since the pump is driven by the cam at 1/2 the speed of the crank.

 

Since you now have oil in the top end, try it again tomorrow, or hours later - should still take about a minute to see oil out of the pushrods.

 

If it seems like it's taking too long, better to tear it back down and find out what is plugged before going through all that work, knowing something isn't right, then having it bite you in the ass again later when you get to do everything a SECOND time. I've been there. It's not pleasant!

 

Only if you're 200% sure there is no way ANYTHING could be in the crank, lifters, pushrods, or any one of the passageways in the block, would I go ahead and install it. If there's bits of metal trash from a previous meltdown in the crank, etc., or chunks of RTV sealer in the main bearings (or anywhere), it can stop things up pretty good. Better to find out now rather than later ...

[Doug_Scott]

I doubt the drill actually reached full rpm. The oil pump can slow a drill down pretty easily. I don't recall ever getting higher than about 40 when using a drill. That was on Chrysler engines though, not that it should really matter. If you got oil to all passages with the drill, I would feel safe running the engine.

[Jsdirt]

Yeah, you're right about that. It's been a while. The pump takes quite a bit of power to run.

 

I remember my cordless drill would barely keep the new Melling pump in my '00 4.3 V6 spinning at what sounded like half it's rated RPM. The 120v drill did much better, but still nowhere near full tilt.