Farmall H

[dcfarmall]

Built stroked H motor, runs good but only has 25lb oil pressure when cold,.. when warmed up goes to about 5 when idling. It does go to 20 when u rev it up. Could this just be weak pump or something else I should look into? Thanks
 

[Janicholson]

If your bearings were clearanced, it should hold 25 plus at idle. The pumps can wear (usually gear wear into the end plate. it can be ground flat, and clearanced to .001 to .0005". The cam bearings could need attention, were they replaced? Ga;;ery plug leaks are also possible if it was boiled out.
The last thing on my list would be weight of oil I would use an oil like 20 - 50 Kendahl, or Other racing oil. Jim
 

[dcfarmall]

Didn't clearance bearings, just got new ones for the tractor and installed them. Took pump apart and sanded wear off plate. It carries 50lb pressure when first started then drops off after time. Has new cam bearings in it too. Got 30 weight oil in it to break in motor. Thinking of running synthetic oil or 15-40 oil, haven't decided on it yet. Thanks
 

[Janicholson]

The stroker crank had to be welded up on an eccentric, then ground round at a greater stroke. My best guess is the diameter might need to be checked with Plastigauge. With the pump serviced, the only things left are the relief valve in the pump, and the bearings in the lower end. Both require removal of the pan to assess. For new it is way low. Did you check the accuracy of the gauge? Jim