Hi, I just recently assembled my first motor. Its a 94 b18b1. I had it honed and decked by a good local machine shop who measured the bore and said it was still at perfect specs. When taking it apart the stock pistons were in good and tight. I replaced the internals with SRP 9.2:1 81mm pistons and Eagle rods with Je High tension rings. When I installed the pistons I had to tap them in with a rubber mallet into the bore. They had a reasonable amount of resistance when pulling them up and down and felt right. However when I put a thumb between the intake or exhaust valves and pushed side to side I could very lightly "jiggle them" My machine shop said it was because they are forged pistons they have a little extra clearance for expansion, Is this true? Does it sound like everything is fitting correct. This is my first build so im not really sure, however the people at the shop said it sounded right and it may be because the rings need to seat, but the specs were correct. Thanks

 

They are correct.The forged pistons have two to three times the clearance that the cast ones had.
Glenn

 

yeah I had the same questions on my first build.

 

Thanks for the responses, that puts me at ease. Anyone else agree with them?

 

if your super worried just get a digital caliper measure the piston then measure the cylinder wall and see exacly how much clearance you have....your pistons should have a spec sheet with them that gives clearance range

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NJIN BUILDR &raquo;</TD></TR><TR><TD CLASS="quote">They are correct.The forged pistons have two to three times the clearance that the cast ones had.
Glenn</TD></TR></TABLE>

 

The machine shop measured the bore and said it was fine, and the pistons are 81mm so im not to worried. The "jiggle just worried me for a minute there. Thanks

 

u r good, keep rocking! post dyno when done!

 

oh yeah and thanks for the sig!!!!!!!!!!!!!!!!!!!! that dude was a TOOOOOOL! haha

 

LMAO (looking at sig)