Ok, I have my 81mm GSR and I removed the pistons and rods (time for a rebuild ) I know I need to rehone the cylinder walls so I went and purchased some 81.25mm P30 Pistons to bump up the compression on it. Now what is the ideal piston to wall clearence for this set up? Ive been told it is .001 , Is this correct?

 

you going forced induction at all? the higher heat can call for bigger clearances depending on the expansion rates of various pistons...

thats all i know lol but just so someone can help u sooner

 

Thanks for the help....tttttt

 

anybody?

 

Best clearance I've seen with a factory piston is .0008"-.001" they don't like to see much more than .002" or else sealing/oil consumption becomes and issue, any tighter, and you might be metal on metal. Compression numbers are best with this clearance as I've seen.

You can also form your own conclusions, factory spec is .0004" to .0016" and service limit being .002".

 

Thanks, so exactly what would you reccomend between the .0008"-.001" ?

 

?

 

With a factory slug I aim for .001".

 

I assume you are talking .001 radial? (or .002 diametral)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by lsturbo* &raquo;</TD></TR><TR><TD CLASS="quote">I assume you are talking .001 radial? (or .002 diametral)</TD></TR></TABLE>

lol someones TRYING to be a smartass!!!!!!

 

Actually i was serious....i am putting my LS together and just got my block back with new pistons and want to take a measurment.

 

think of it as you would for the clearance call-out on anything else. not per side but overall.