I didn't really want to be reving the knackers off an engine with a new crank and pistons with running in oil? I have been driving around Northumberland, very steep hills and have done 300 miles I not ragging it but I'm driving it quite hard, does this mean I've glazed the bores? I have heard so many conflicting reports over the years, I haven't got a clue, some say put synthetic straight away others put mineral oil in some say keep the revs down but plenty of throttle, others no full throttle. On my previous engine I kept the revs down and around 350 miles on mineral oil, then drove it as if it was run in on synthetic after it blew up I inspected the the remaining 3 liners and they seemed to have bedded in fine with no glazing and it didn't use any oil apart from a bit on track days. Anyway I'd like to thank Dave Andrews for his advice and supply of parts, plus his invaluable web page, I'd be lost without it! Up to now oil pressure is 60+ at 70 degrees oil temp, the water temp stays at steady 80 degrees and only goes up to 90 when stationary for 5 minutes