I just dropped my new block off at the machine shop to be bored out to 81.5 mm for some JE 9.0:1 CR forged pistons. The machinist there said that he recommends boring them a little larger for a turbo application. What is the general consensus here? I figured that JE would have already taken this into account and made the piston the correct size for the sleeve, not the other way around. Help me out here....

 

Turbo motors create more heat causing the piston to expand. Your machinist is taking this into consideration. I would just tell him to run the recommended clearances that came with the pistons. I am sure that JE knows more about the expansion tendencies of their pistons than your local machinist.

 

bore to 81.5mm and not .01mm more than that. clearance built into that piston

 

From Mr. Honda-tech himself even... advice taken Earl, you are the man. I am sure you get that on occasion though...

 

haha, I'm hardly Mr H-T. I'm blown away by some of the really smart people on H-T.

 

earl is The Duke of Turbo

Sonny

 

Alright earl, I am giving up on bearing color codes... I need a set of ACLs.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sonny &raquo;</TD></TR><TR><TD CLASS="quote">
earl is The Duke of Turbo
</TD></TR></TABLE>

lmao

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">bore to 81.5mm and not .01mm more than that. clearance built into that piston</TD></TR></TABLE>

From what I've heard, JE's slap pretty badly. Is this because they spec larger clearances or their alloy does not have as high a silicon content?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">bore to 81.5mm and not .01mm more than that. clearance built into that piston</TD></TR></TABLE>

...but not the SRP's then?