Hi friends,i would like to know how much can i bore a stock sleeve to do an oversize piston in a jdm itr?

 

An 82mm bore would be the absolute max theoretically, though piston availability realisticly limits it to 81.25 or maybe even a custom 81.5mm bore.

 

Is it possible to find 82mm size?
If yes ,any ideas from where please?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM97R &raquo;</TD></TR><TR><TD CLASS="quote">Is it possible to find 82mm size?
If yes ,any ideas from where please?</TD></TR></TABLE>

But why?
I'd go with some CTR higher compression pistons before I go experimenting with the structural integrity of the block! IMHO

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">An 82mm bore would be the absolute max theoretically, though piston availability realisticly limits it to 81.25 or maybe even a custom 81.5mm bore. </TD></TR></TABLE>


No theory here. 82mm is more or less the maximum size, and it is done all the time.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zygspeed &raquo;</TD></TR><TR><TD CLASS="quote">

But why?
I'd go with some CTR higher compression pistons before I go experimenting with the structural integrity of the block! IMHO</TD></TR></TABLE>
what he said

 

Yes,i know it's better what you guys are saying but i have some small scratches in the sleeve caused by a faulty plug and now i have to hone the sleeve cause at high revs the car is smoking.That's why i have to know what size i have to do. Thanks alot guys for your opinions.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDM97R &raquo;</TD></TR><TR><TD CLASS="quote"> ... but i have some small scratches in the sleeve caused by a faulty plug and now i have to hone the sleeve cause at high revs the car is smoking. </TD></TR></TABLE>

I understand, but there is a significant difference between needing to be honed (due to some cylinder wall scratches), and "boring" it bigger to 81.25 or 81.5 mm much less 82mm.

But as Steve said above, 82mm is entirely possible but it will need to be done by a machine shop.

 

Show block to machine shop once you get it dissassembled. They should be able to tell what the minumum boring you can do to fix the problem is, unless you want to go to 82mm.

 

No i don't want to go to 82mm.I think i am going to purchase a set of ctr pistons 81.25mm from spoon.It's enough that size.Do you think it's a good idea?

 

Why dont you take the block to the machine shop to see how bad the scarring is (how much they need to bore/hone the sleeves) before you purchase new pistons? If its not bad at all 81.25 will be sufficient....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18c-rDC2 &raquo;</TD></TR><TR><TD CLASS="quote">Why dont you take the block to the machine shop to see how bad the scarring is (how much they need to bore/hone the sleeves) before you purchase new pistons? If its not bad at all 81.25 will be sufficient....</TD></TR></TABLE> That's a good idea .i try to do that but i have to wait about 2 weeks with the car in the garage before the pistons arrive.Ok thanks alot all of you for the info you gave me

 

If you don't need the car on a daily basis, then I would pull the block and take it to machine shop to have them look at it to determine what the minimum boring necessary is.