oil pressure

As long as your oil flow is good, you should not have any problems - so make sure your filter is clean . . . . . .

HTH

If you're running that kind of dynamic range with that heavy an oil, and clean at that, an overhaul isn't far away. Course, you can buy a lot of oil for what an overhaul costs. I have a MF35 that I have to run HD 40 wt in it to get an oil pressure that I'm comfortable with. Course this winter I will have to drop down. Will probably go back to 15w-40 then back to 40 next summer. I just don't to tear into a Perkins 3/152 for low oil press. You can't drop the pan and do the mains on that engine. There is no pan. The bottom of the engine is cast iron and is used as the frame of the tractor, rather than the engine block that most mfgr's use. Had it been simpler to get the pan off, I'd just do the lowers and be done with it.
Mark

I ran the old girl hard this evening, and my figures above were a bit out - I get an amazing 20psi at full chat when hot (and I do mean HOT as my fan belt is slipping a bit . . .) so I'm not going to worry too much about that rebuild just yet.

Most of the Standard engines lose the bulk of their pressure on the camshaft bearings - my mains and big ends are all AOK - and as long as the top end and valve train is getting a good sluicing of oil there should not be much to worry about.

Like you say, it's all in the viscosity, but I would add that flow is also needed to carry the heat away and prevent the oil breaking down.

Happy days!

Interesting point you make about cam bearings. I never give them any thought. Do you have significant experience that on a Diesel engine, the cam bearings would preceed the lowers in wear?

Would be good to know and maybe I need to be more thorough the next time I tear into one. (Don't have a cam bearing puller nor installer.)

Mark

If the oil isn't well maintained, the (essentially poor) lubrication to the camshaft journals (which are plain bearings, not ball or roller so don't need pullers) gets worse as the hole is semi blocked by gunge - so you get a leak path because of the wear due lack of lube. This means a drop in pressure and a lack of top end lubrication - so rattly valve train and worn guides etc.

Rebuilding/resizing/renewing the camshaft bearing surfaces is a major pain (and also $$$$), so doesn't often get done.

Rebuilding your oil pump can also be a bonus - if you look back in the archives to sometime in 2003 I posted a load of stuff on rebuilding oil pumps (the company I used to work for made the things, even for the Ferguson engine) and the things to watch out for on clearances, and what makes an inefficient pump.

More I cannot offer - HTH.

Mark