Machinist has OK'd the block for a 4.060 bore(60 over on a 392) but he wants pistons in hand before he bores/decks. I'm not finding forged shelf pistons at that oversize so looks like custom, I think I'll go with Ross on the recomendations I see here and elewhere.
But Ross will need alot of specific info to make them. Machinist will measure the deck height as it is now, he says it doesn't look like the decks have ever been recut but since he wants to do both decking and boring in one setup I'm a little nervous about getting everything right on the first go. So I won't know finished deck height until the operation is done but how do I know what deck height dimension to give Ross?
So a little guidance for a virgin custom piston buyer would be appreciated. I suppose I should give the machinist my finished rods to verify rod length along with the cam and what the hell, the heads too(heads have bigger valves and been milled to 97cc)? What about head gasket choice? I'm thinking I should build in safety margins for, like, piston/head, piston/valve clearances. Its possible I might change the cam after its built, depending on how it runs. Its better to loose a little compression than smack parts around, right? Argh, clouds swirling in my head!
Ordering Custom Pistons
Moderators: scottm, TrWaters, 392heminut
Re: Ordering Custom Pistons
It would seem to me that he could/would/should do the decking first/seperately. Mainly decking if measuring shows the deck isn't square to the crank top to bottom, front to rear & that both decks are equal distance from the crank. Get that done first, how else would you be able to figure piston to deck hieght to order your pistons & yes, he should have the pistons in hand when he bores each cylender.