[Hotrod_Dan]

Hello all, hoping for some pointers on a strange issue with oiling. My brother just rebuilt the bottom end on a chevy 250 inline 6. Had the crank turned and plopped in undersized bearings the machine shop supplied for him. I had him check the clearance just to be sure and all checked out. Re-sealed the engine and now it's back in the car. He didn't mess with the cam, lifers, or pistons, just shaped up the crank. Everything else stayed in the block. Important to mention that he had the engine upside-down on the stand for about 2 months before he could get it back together.
Last night we were going to fire it, but I wanted to prime the engine first. In doing so, we got no oil at the rockers except #3 intake which was going like a champ! I have never seem this before and idk what in the world could cause it to only pump oil to one rocker. Any ideas?

 

[BogiesAnnex1]

Oil to the rockers is controlled by the lifter, there is either a a small shuttle valve in the bottom of the pushrod cup as that faces into the reservoir of the lifter or there is a bleed hole. The push rod is hollow. Any debris blocking any of these parts will stop the oil flow to the rockers.

Bogie

 

[Hotrod_Dan]

Oil to the rockers is controlled by the lifter, there is either a a small shuttle valve in the bottom of the pushrod cup as that faces into the reservoir of the lifter or there is a bleed hole. The push rod is hollow. Any debris blocking any of these parts will stop the oil flow to the rockers.

Bogie

I forgot to mention, I checked the pushrods to make sure they were clear. They were. I guess I we could go through and pull out the lifters and give em a clean.

 

[BogiesAnnex1]

I’d lube it up and fire the engine, I missed the part where you were just pre-oiling. Often lifters will not transfer oil when in a static position. Sometimes cranking it around by hand while pre-oiling will work, sometimes not. Firing it up for a few minutes with some oil squirted on the points needing it will let things get dynamic and you can see if that gets some oil delivery before diving in to remove and clean lifters.

Bogie

 

[Hotrod_Dan]

I’d lube it up and fire the engine, I missed the part where you were just pre-oiling. Often lifters will not transfer oil when in a static position. Sometimes cranking it around by hand while pre-oiling will work, sometimes not. Firing it up for a few minutes with some oil squirted on the points needing it will let things get dynamic and you can see if that gets some oil delivery before diving in to remove and clean lifters.

Bogie

Thanks so much bogie! We will fire it and see how she does.

 

[bk2life]

Exactly what Bogie said. If you are getting oil to at least one rocker, than fire it up. The whole idea of priming the oil pump is to make sure there is no air pockets in the pump cavity and oil passages. Since you are seeing oil flow, even at only one rocker, the majority of the system is primed. Start her up and watch the oil pressure on the gauge, should show pressure almost instantly.

Let us know how it worked out for you