about a year ago i deciced to rebuild my chevy strait six 250. we went 20 over and shortly after start up piston slap developed in number one. No bearing damage , crank or rod. No damage anywhere in the engine except for the passenger side of number one. There the piston had eat enuf out that apon rebuild number one was sleeved cause it wouldnt clean up. The first time we had the machining jobbed out. the second time we did the machining cause we felt maybe faulty machining was the culprit. This time the engine was run longer , harder , and further. Piston slap and damage occurred in the exact same spot only not as badly. Well everything else was fine as far as we could tell again so we were guessing that maybe the intake had a leak due to warping and had caused the damage by running the number one lean. both the intake , exhaust and head were milled to correct what we thought was the problem. a new water pump and radiator were also installed and the operating tempature had dropped abbout 15 to 20 degrees running now from 190 to 210 all looked good for about 3500 miles. I've got piston slap on number one again. oh and this is the kicker. number 3 was a new block we machined ourselves again. the number one on that engine was significantly more scored than the other 5 we discovered after teardown. The only thing i can think to check is the head which was purchased rebuilt from a good place. Is there anything peculiar to these sixes that might explain this? Does anybody know a good shrink?
