Oil pressure

seattle##gs · 2026-03-01T17:33:43-0700

New motor. Old pump. I turned the rod bearings around so they blank off the spit hole in the rods. When cold the OP is at least 60. I rode it approx 2 miles and it settled down to 40. I realize the motor is not at operating temp yet but this is pretty good.

DennisMo · 2026-03-01T20:59:11-0700

I am curious why you would cover up the spit hole.
I would think that the oil that goes up has two functions.
Firstly to work its way to lubricate and secondly to cool the pistons

seattle##gs · 2026-03-01T21:51:59-0700

I was told the spit hole has no more function. It was used to solve an inferior piston design. I covered the hole to increase oil pressure to the rods and lifters and cam.

robs ss · 2026-03-02T00:00:34-0700

seattle##gs said:
I was told the spit hole has no more function. It was used to solve an inferior piston design. I covered the hole to increase oil pressure to the rods and lifters and cam.

The important lubrication to the cam is not pressure-fed. It is dribble-fed by oil returning from the head via the pair of chamfers on the front of the lifters. it dribbles onto the backyard rotating lobes and into the contact patch of the lifter.
It goes without saying that the lifters are not pressure-fed.

kommando · 2026-03-02T00:28:21-0700

The spit hole is at the wrong place, the bearings most heavily loaded position is exactly where the spit hole is.

Oil pressure

seattle##gs

DennisMo

seattle##gs

robs ss

kommando

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