Inside a newly-acquired engine

[Ian Williams]

If its a freshly built engine that has not had the oil changed regularly during the running in period I would suggest that the sludge you have found is to be expected. I would make a few checks for assembly errors that could have been made by the previous owner but otherwise probably an excellent engine. I had problems with two sets JP pistons but that was about 25 years ago now so you would expect those issues would have been solved a long time ago. It seems they were not ground properly and with normal bore clearances seized on gudgeon pin bosses even after extensive running in.