I found a fairly straight head on a parts engine, the only thing is these cracks on every PC, should I be worried enough to replace them before I get the head ground? I've heard Giles can get them but they can be a B to remove.....Sorry for the picture quality....
to each his own, I had 3 precups in the head I use and I replaced them. The're not that bad to remove and you will likely find the new ones will be a bit loose. This is normal.
looks normal, but u should remove them and cut them seperately on the top so that the face and whistle hole are never changed
I have found that some of the cups aren't interchangeable. Some are different volumes too. Unless you're cranking off a lot on a surfacing, I don't think that there should be any appreciable change to the whistle hole to necessitate removing them.
if you surface the head with them in the cracks can catch and they get chipped up on the edges, the pre cups are supposed to protrude a few thousandths, so if you're taking a few thousandths off the deck of the head, you're taking even more off the pre chamber. they're supposed to be cut seperately and protrude a few thousands
dont worry. so as long as the cracks dont go into the fire ring.. you can see the imprint of the fire ring on the head