In my first post I remarked that a month ago when I first looked at this truck I pulled a valve cover to get the head casting numbers and it was super clean inside, no sludge whatsoever. I drained the oil today and changed the cartridge filter and the oil that came out was really clean too.
The Task Force hoarder that I bought this truck from (he had 15-20) told me it had sat in that spot for at least 8 years, so who knows when that oil was put in.
I cleaned up the aftermarket "oil cleaner" that appeared to have sat on the driver's side inner fender since 1955, and it turns out it is a "FRANTZ Oil Cleaner". This is one of those non full flow units that uses a roll of toilet paper inside to filter the oil. Judging from the cleanliness of the inside of the engine, it works.
They started selling these in the early '50s and still sell them today. The original owner likely installed it when the truck was new and had the '55 265 with no oil filter.
They work by constantly filtering a small amount of the oil, tapping into an appropriate fitting on the engine to steal some of the oil away. They do not plumb into the main engine oil system where all the oil has to circulate through it.
This one is fed it's oil from a tee fitting before the oil pressure gauge, then returns the filtered oil to the pan via a fitting that is brazed into the side of the oil pan above the oil level.
He must have been happy with it because he retrofitted it to the new engine to work in conjunction with the canister filter.
Before I bought the truck I wanted to be sure the engine wasn't seized so I had the seller pull it a little way with his Bobcat with the trans in high gear. I watched the fan and it spun smoothly and there was no initial jerk or anything to indicate stuck rings.
When I brought it home last Thursday I pulled all the plugs and sprayed a bunch of penetrating oil into the cylinders to loosen up any potential corrosion. After I changed the oil today I hooked up a fresh battery and did a compression test. All the cylinders were 145-150 which I thought was pretty good for a cold engine.
We'll see how she sounds tomorrow if I can get her fired up.
