98Z28CobraKiller

iTrader: (17)

So I am starting to search around for pistons and rods to forge this LQ9 bottom end before I blow it up. I was looking at the Wiseco book and it says that the aluminum blocks have a 9.240 deck and the iron blocks have a 9.230 deck. The pistons show that with a 6.125 rod and 3.622 the piston will reach 0 deck at 9.240 which would put me .010 out of the hole assuming it doesn't need decked. Is .010 too far out of the hole? The headgasket will be a stock .055 mls. In theory, wouldn't I still have .045 between the piston and the head? The reason that I am trying to use a 6.125 rod is that I have a set available to me. Thanks.

fast01

iTrader: (16)

Assuming your numbers are correct, with nice tight bearing clearances and good steel rods and bolts, you'll be fine with .045" clearance. Optimum quench is between .035" and .055". Any less, you may have contact at high RPM, any more and you'll forfiet the benifits of the quench design.

slow trap

iTrader: (22)

i'd say there are quite a few builds with the pistons .010" out of the hole. i think stock shortblocks stick out quite a bit and my forged 348 stuck out between.006-.008"
you will be be in great shape with .045" clearance as long as your head gasket bore is larger than your piston bore.

Beaflag VonRathburg

iTrader: (176)

There's a ton of builds with the pistons out of the hole. Especially when the block has been decked. I just had to change my build with a new set of pistons. The old ones are a 1.1155 CH while the new ones are 1.125. My block has been decked so they are going to stick out quite a bit.

jmm98LS1

iTrader: (28)

Will work fine, .010" isn't bad at all. The pistons in my 370ci are .012" above deck (6.125" rod).