I bought a spare block cheap a few months ago not sure if my original block was good.
The block I bought was a transplant 235 that came out of a 1952 GMC 3100 which was not the original. The numbers on the block were 072559 F55Y, 3836233 & C165. The numbers on the heads were B20 887, 3701187, & H123. He said heard a bang and the stopped and he shut it down and towed it home. He pulled out the spare runner he had and installed it.
I looked at the motor taking a chance that the block was good in case mine was trashed. I turned the vibration damper and it tured smoothly. I pulled the valve and push rod covers and everthing looked clean no sludge or gunk.
Now as the plot thickens, today I removed the head and I was suprised to find hydralic lifters. I thought he installed them because I knew the regular standard trucks did not have them. I pulled the oil pan and there is where I found the problem. On the little counter weight by #3 piston it was worn down looks like the cam lobe dug into it. It was also on the smaller counter weight by the #4 piston. I removed the timing gear cover and found another suprise, the timing gear was warn down and it was fiber so I am thinking this motor was from a 1955 car.
I have put some pics so you can see but why could this have happened? Was the cam bearings bad or main bearings bad? The cam shaft where I thought it might have rubbed on the lobe was not sharp or looked worn or damaged.
The pistons looked to have a lot of carbon on top of the piston and intake valve, the heads exhaust valves looked very white on the exhaust side. Is this normal or was the fuel air mixture not correct? The cylinder walls looked very good with no scrathes and smooth and clean.
My last question, should take what ever parts off I can salvage and boat anchor the rest? My original block was frozen and sat for about 20 years so it was very differnt situation. I just want to understand what happened to this one on the 55. This is my second 235 tear down.
http://i1291.photobucket.com/albums/b554/stovebolt56/55%20Spare%20Engine/55headview_zpsded81fa1.jpghttp://i1291.photobucket.com/albums...re%20Engine/55pistonview_zpsd7df6870.jpghttp://i1291.photobucket.com/albums...unterweightby3pistonpic1_zps7db4d48d.jpghttp://i1291.photobucket.com/albums...unterweightby3pistonpic2_zpsc0bbd59e.jpghttp://i1291.photobucket.com/albums...20Engine/55fibergearpic1_zps9b6161f1.jpghttp://i1291.photobucket.com/albums...20Engine/55fibergearpic2_zps77409944.jpghttp://i1291.photobucket.com/albums...e%20Engine/fibergearpic3_zpsbaede37b.jpg
