I'm feeling a lot like a 'tard at this point, but I've come to a conclusion. The so-called mechanic who built my motor may have not installed the 81.25mm US-spec ITR pistons like he said he did. The motor has been running great, as well as any other Ls/Vtec I've seen with my own eyes, but I'm still left wondering if I really have what I think I have.

So this leads into my question: Is there a way (get creative here) to identify the pistons in my B18A block, without removing the B16 head? I'm looking for some sort of markings or other ways to tell if I have the ITR's or just stock B18A pistons. I know the dome heights are significantly different, but is that something I would be able to tell by looking down the spark plug hole? Anyone in-the-know please let me know.

 

Here you go to get some bites

 

whoa...look at the dome on that third piston on the right!

 

ir camera in the spark plug hole. the os will be carbon covered but u should catch the part number

 

wouldnt a compression test be higher with higher compression pistons? (just guessing)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iH8RICERZ &raquo;</TD></TR><TR><TD CLASS="quote">whoa...look at the dome on that third piston on the right! </TD></TR></TABLE>

Yup, those are (from left to right) USDM B16, JDM ITR, and CTR pistons.

Any idea what part #'s would be printed on the top of the piston if I were able to get a camera shot down there?

 

p73-a0 pistons. should have just over 11:1 c/r aswell. get a compression gauge on it and see if u got good numbers.