CM871 oil pressure

[dhirocz]

I did 6 in my 871.
Hot idle: 22psi @ 620 rpm
Hot high idle: 45 psi @ 1200 rpm
Hot 700rpm: 25 psi
Hot 800 rpm: 30 psi
Hot 1600 rpm: 47 psi
That's with half a gallon of 80-90 in a fairly worn 871 a 740k. I did roll new bearings into it and changed cooling nozzles at that time. New cam bearings, oil cooler and thermostat as well.

I too dropped mine in first, but had the pump removed and was able to verify they all dropped in and sat down flat before reinstalling the pump, since the bore was vertical with my pump in a vise with softjaws. I've shimmed a number of other pumps before, and personally, wouldn't do it unless the bore was vertical. I took note of the bore and why they need to be flat, so if I did one with the pump installed, I would think the cup is the only way to go. I also trimmed the tab on the pump shims on one side to not interfere with the gasket.

It does sound like a couple dimes slid out of the bore and got fed through the pump...if that pump is not perfect I'd consider replacing it now...but at a minimum, find those pieces!