I could fertilize several acres of garden with all the bovine effluernt that's been published on the Stovebolt forum in the 15 years or so I've been here, about which oil to use and pontifications about filters of various types and designs. Everybody's got an opinion, and opinions, like "noses" can get pretty "smelly". Before you can "catch it in a filter" you're going to have to figure out a way to dislodge those layers of sludge that have been building up for decades. I like to use a gallon or so of Diesel fuel, added to a full crankcase of cheap oil, and run the engine for 20-30 minutes at a fast idle with the crankshaft and connecting rods splashing into the over-filled crankcase. No driving, or putting any sort of load on the engine- - - -just give it a good wash job with the solvent-diluted oil, with the crankshaft serving as the agitiator in the washing machine. Drain the oil while it's hot, and a large quantity of the sludge will come with it.
If, after washing a bunch of sludge out, you find that the engine is worn out (noisy bearings, and/or excessive blowby and oil consumption) at least you've gotten a better head start on cleaning it up than you could ever do with a brush and solvent after removing sheet metal parts like the oil pan, side cover, and valve cover. If you get lucky and find you've got a usable engine, install the original-equipment type bypass filter, fill it with 15W-40 oil, and drive on!
As always, the opinions expressed by this writer might be worth exaxctly what it's costing you to read them. Anyone with a different opinion, please note the sprig of mistletoe attached to my untucked shirt tail!
Jerry
