A few years ago I saw an ad for an old Chevy engine and I went out to the guy's place. He was a Buick nut, and didn't want the engine. I was looking for a high oil pressure 235 to rebuild for my '53 Chevy 210 convertible. I wanted this car to be a driver/fun car, so I wasn't interested in matching numbers, besides it is a 3-speed car, and I didn't want to waste time on the old low oil-pressure 235.
When I got there the only engine he had was a 1961 261 and it looked weird. Instead of being covered with 1/2" of black sludge, like I had expected, it was perfectly clean but rusty--there was no oily residue on the outside of the engine at all, nor evidence of any paint whatsoever. So that got me curious. I pulled the oil pan, and the inside of the bottom-end looked clean enough to eat off of--no black sludge at all. I pulled a couple of bearing caps and the crank looked very, very shiny. I pulled the head and the cylinders were only slightly rust-hazed. So we struck a deal for $400. The engine came with a stock 261 oil filter and an intake but no valve train.
I loaded it up into the back of my truck and took it home. That night about 3:00 a.m. I was awakened by my truck alarm going off, immediately followed by the sound of an old Chevy with dual-glass packs roaring away (You know that sound--it is very distinctive) I got up and checked my truck out--evidently some morons had seen my engine in the back of the truck and decided to try to steal it! They didn't get it--and I drove to a friend's house then and unloaded the engine into his garage.
However in trying to disassemble the engine I found out it was VERY stuck. I couldn't even rotate it enough to get the upper pressure plate bolts off--I had to cut the darn bell-housing off with a Sawzall!! That was work! I squirted a lot of #2 diesel all over the engine and let it sit for a few weeks, and eventually loosened up the varnish. The engine was really glued together from sitting for so long.
When I was taking the oil pump off, I discovered that one of the brass fittings, which hold the copper oil pipe was cracked. In this state it would not have tightened & sealed the oil supply pipe at all, and the engine probably would have showed low oil pressure.
I took the engine to my machine shop and everything mic'ed out really good. I was able to use the stock pistons, and it didn't need the crank turned either. One cylinder had a tiny bit of rust going into the cylinder wall far down on the stroke, but it was only about a thousandth off and my machinist said to just ignore it.
So my guess is that this was a factory warrentied engine. My guess is that because of the cracked brass nut, the oil pressure would never come up to normal, and instead of fixing the problem the dealership just replaced the engine. What do you guys think?
