Posted by Steve Kanavas on August 03, 1999 at 19:51:44:
In Reply to: Motor oil preferences: straight or multi-weight? posted by K Bishop on August 03, 1999 at 09:58:51:
The general consensus is, without a filter use ND oil. With a filter present use detergent.
I Use 20W50 in my 230. It seems to hold oil pressure better in very hot weather. Less consumption too. The bottom end of this engine has about .003 clearance on rods and mains, therefore it's a bit loose, but a new oil pump. I'm unsure of the cam bearing clearances. On 30 weight, the pressure drops to about 8-10 psi at hot idle. 20W50 shows about 20 psi at hot idle.
On 20W50, with revs over 1200 rpm, it's on the relief valve.
I'm cautious not to run the engine past 1200 rpm while it's cold though.
If your engine hasn't been in service for many years, It may be worth your time to pull the valve covers and scrape out the crud in that area. Be sure to blow out the return holes to the crankcase, or your scraping and cleaning can clog them.
I learned a neat trick from an old farm type guy for cleaning the engine oil pan the easy way.
Put a drain pan with kerosene under the truck oil pan.
Get a small submersible pump such as for an aquarium.
You now can wash out the valve area, with the kero flowing into the oil pan, and into the drain pan.
When the valve area is clean, just put the hose down the oil filler for a few hours. You won't believe the crud that ends up in that pan full of kerosene!
steve