Motor experts I need your opinion...my motor is out while the wheel house repairs are being done. The motor is down to the short block for cam, head, valve train and oil pan additions. I noticed on one of the cylinder walls there are spots that look like water spots where the metal is discolored (a darker gray color). There's no rust on the surface and the surface is smooth(no nicks, dents, indentations....just these "water like" spots where the metal is slightly darker. I took some 200 grit sand paper and hit the spots very lightly to see if they would lighten up and they did. The motor was bored .030 over in 2003 reassembled and was only driven from the shop to the previous owners house and sat until I bought it. There's less than 20 miles on this motor. The cylinders still show pretty fresh hone marks. Also in the bottom of the same cylinder bore when the piston is at the bottom of its stroke there is an uneven wavy line about 1/2" above the piston, that gives me the idea that it might have been created by a little water sitting in the bottom of the cylinder at one point in its life. Not sure if it was before or after the rebuild? The spots and the line are both on the outboard side of the block.
Since the block was bored by the previous owner (pistons are marked .030 over), maybe there was a problem at that time which necesitated the boring and they didn't want to go any farther on the bore? My biggest concern is the Clevelands are known for thin walls and it may have pin holes that are seeping now.
Any idea what these spots could be?
Best regards,
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