[Fot] Fw: Help with Oil Pressure Problem

[Larry Young]

I agree it would probably not be excessive rocker clearance as Greg 
explained.  However, no one has mentioned excessive cam bearing 
clearance. Not long ago we discussed this same problem with 6 cylinder 
motors. My TR250 has the same symptoms and I have wondered if cam 
bearings would solve the problem.

On 3/6/2014 8:32 PM, Greg Solow wrote:
> I do not believe that the rocker assembly could cause this.  The 
> standard oil feed is though a restricted hole from the rear main 
> bearing to the rear cam bearing, then the feed is intermitently pulsed 
> by the rotation of the camshaft lining up a spiral groove in the rear 
> cam journal and some flats machined into the journal. I have by passed 
> this system and fed oil directly from the restricted drilling from the 
> rear main, to the drilling that goes up to the head. Doing this feed a 
> lot more oil the the rocker gear, but did not affect oil pressure at all.
>     Excessive clearance in the oil pump, either excessive end float on 
> the gears or excessive tip clearance between the rotors will give low 
> oil pressure at idle, The oil leaks back withing the pump at it 
> rotates slowly, but at the reves come up and the pump turns faster, I 
> think it can overcome this internal leakage and the pressure in the 
> engine will come up.
>                        Greg Solow