TO-20 oil pan

Also, I can't seem to get a grip on visualizing how the oil moves around in the pan. I have my shop manual, but from the images it looks like that inner can that surrounds the filter and mesh screen is held down on the filter access plate by the spring above it. If this is correct, how does the oil get inside of the can so it can get picked up by the intake tube inside of it?

Thanks.
John

On the oil flow - You have it right, except... the oil filter & mesh strainer is just a little taller than that steel can cover, so the filter & mesh strainer is pressed down on the oil pan cover plate (the plate that you remove to change the filter) by that spring and steel can, but the steel can itself isn't touching the bottom when all is assembled. The actual oil flow is that about ~80% of the oil is returned to the crankcase pan from the crankshaft journals, and the overflow from the head thru the camshaft. The remaining oil... ~20% goes thru the center main bearing, down thru the filter tube and into the oil filter. So the oil filter flow is from the inside to the outside. If you look at the metering holes on that filter tube you will note they are quite small, so not a lot of filtration going on there. The mesh strainer strains the oil being sucked into the oil pump so it doesn't get any particulates into the tight clearance pump gears. My view is that mesh strainer is doing the most important work, and the filter itself is not contributing much.... providing your oil change frequency is as prescribed by the owners manual.

George

That sure is a Rube Goldberg set up, and I wish I had an external filter system. Makes me wonder if the engineers who designed this thing were smoking something kind of funny back then.

Dan