No oil pressure when running?

[Pich]

Hi,

Hope someone could help me with this.
I built a 440 stroker 493 with comp cam hydraulic roller camshaft  xr280hr and comp cam pro magnum retrofit roller lifters.

When a prime with a drill there is oil pressure showing on the the gauge half way but when i fire it up, no oil pressure.


What is going on?

[69bcuda]

Using a mechanical gauge? Half way up is what psi?

Is the intermediate sound? No slipping of the gear or hex?

[Pich]

60 psi with the drill at low rpm.

I just switch to roller cam and pressure was ok before with hydraulic flat tappet.

Could it be the roller lifters? Like if oil is leaking somewhere only when running.

The lift of cam is .541" could this expose the lifter?

[Pich]

Intermediate shaft is ok, lenght, gear., and since its the same that i used 2 weeks ago with hyd flat tappet cam and was ok with good oil pressure.

[Pich]

60 psi with the drill at low rpm.

I just switch to roller cam and pressure was ok before with hydraulic flat tappet.

Could it be the roller lifters? Like if oil is leaking somewhere only when running.

The lift of cam is .541" could this expose the lifter?

Just found the second rocker shaft stud from the rear is broken. Could this be the cause of oil pressure lost when running only?

[70chall440]

I would say doubtful, but stranger things have happened. I would suspect a deeper issue.

[Pich]

**update**

i removed the valve cover on passenger side and found that one pushrod was off the rocker and the lifter... just standing there!

I now realize what's happening: when engine is running, the lifter with no pressure on it would go too high in the bore with only the link bar to retain it from going out of the bore. Since lifter is too high, oil goes out and no pressure.

when i was priming the lifter would back down and pressure was ok!!

I now have to understand why this happened since Im sure preload was ok on all lifters.