oil pump help

[Ron Gusack]

Originally Posted by Ed Wright

Ron, from what I saw with the local circle track cars, I would say you are mistaken. I posted what I observed. More power required to run the big pump is the only thing I know of that would wear gears like that. Old as I am, I haven't seen everything yet.

From your description of the oil pressure you are seeing, I would say you problems other than the pumps. I just put a new Moroso std volume pump in my spare engine, which I recently sold. Oil pressure was solid at 60 psi all the time. Hot or cold (5W20) idle or WOT. You have something wrong somewhere.

I have an old rear main cap, with a gauge on it. I bolt my pumps on it, drop it in my parts washer, and spin it with a 1/2" drill to see where the relief valve is set. Whatever it shows there, is what it shows in the car. My thinking is solvent, being thin, would be similar to hot, thin weight oil.
I noticed solvent spraying out from the area where the pump mounts. The machine marks was the culprit. Also, some do it where the end plate mates to the main housing. I have a surface ground plate I use with wet-or-dry sand paper in the parts washer for sanding piston tops to correct the deck. I started lapping the oil pump mount, end of the housing, end plate, and pull the dowel pins from the rear main cap. I lap all the machine marks from those four surfaces. Stopped the leakage. I prefer my oil going into the oil galley. I don't see how excessive leakage those two places could help anything. Some machine marks are worse than others. Hope this gives somebody something to look at.

So you tap the rear main cap that's actually going on the race engine? How else could you determine that there was a mating surface leak. Do you leave the threads in the cap when it goes on the race motor?