I'm in the market for some forged pistons and looking at all kinds of deals on ebay or here on honda tech I started thinking about what the difference was between a b18b and a b18c pistons was besides the compression and bore size..

After trying to look at some sites for part numbers and see if they matched up I found absolutely nothing on this, the only reason I could see the part numbers were different was beacause of the difference in compression..
So now I'm thinking maybe the skirt size is different between the two and thats about the only thing that it could be??

Now can someone varify if they are the same or if they are different in size??

Thanks,
Adi

 

TTT

 

The valve reliefs may be smaller on LS pistons than on the GSR pistons. Also, the compression ratings are going to be off if you swich them from on application to another because of differences in combustion chamber volume. Not sure, but there could also be differences in piston pin height, probably not though.

 

No difference in piston pin location. Nothing to do with skirt size or bore size etc. Compression will be different, but easy to find what it would be with c-speeds compression calc.
The only difference is the cuts made for the valve reliefs. Its ok to use a gsr piston in LS, but i dont think its ok for LS to go into gsr.....dont trust me on this because im not totally sure. I used gsr 9.8's in my LS (still using with gsr head soon) and I didnt ever run into a problem.....although i never clayed the motor during assembly cause Im laszy when it comes to building my own personal motors

 

Ok cool thanks for your replies mos and dan, I'm looking at some 10.4:1 compression gsr pistons right now and after i did that calculator deal on c-speedracing I figured out the compression will be about 9.8:1 at the most, but than I also remembered that I'm gona run a inlinepro head gasket again so it shouldn't be an issue at all....

Thanks,
Adi

 

Has anyone tried enlarging the valve reliefs to accmodate the larger vtec valve diameter?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by T4sol &raquo;</TD></TR><TR><TD CLASS="quote">Has anyone tried enlarging the valve reliefs to accmodate the larger vtec valve diameter?</TD></TR></TABLE>

Just buy JE LS pistons.