Cracks in Pre-Cups

[hippiekiller]

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....

[rodpaslow]

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.

[RabbitJockey]

looks normal, but u should remove them and cut them seperately on the top so that the face and whistle hole are never changed

[belchfire]

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.

[RabbitJockey]

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

[kevinm]

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