I just bought a b16 with a block guard and bored 20 over i need to buy pistons and what not for it. I'm not sure what size pistons to get i believe the stock bore size is 81mm.

Thanks for all the help

 

?

 

81.20 mm

 

.20" = .5mm
B16 Bore = 81mm

81 + 0.5 = 81.5

 

yeah the +x nuimber is in .mm Just remember to try and have all the info and Parts you need before you do something drastic like boring and honing your motor. B/c You'll save yourself so much hassle and wasted time. Good luck...Got any pics of the block?

 

so it has been ran on this 20 over bore i have to have it honed that isn't going to open it up more is it?

 

no

 

so i see i got 2 different answers one what 81.20mm and the other is 81.50mm which is it

 

81.50

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by davidcrx89 &raquo;</TD></TR><TR><TD CLASS="quote">so i see i got 2 different answers one what 81.20mm and the other is 81.50mm which is it
</TD></TR></TABLE>

20 over is a phrase used by machine shops signifying twenty thousanths of an inch. Notice how when you order pistons from JE (Example), they don't sell you 81mm pistons, they sell you 3.307" pistons. You have to do the math from there, 1mm is equal to 0.03937 inch.

 

you have to get the oversized pistons FIRST and then the machine shop measures them and machines the block for them with the proper clearance, you CANNOT have it bored first!

 

i know a lot of people who have done that. some people don't have the tools to measure if it's been bored before, so they take it to the machine shop, the machine shop says they will bore it .20 over, they get it, it's honed to perfectly match the pistons (which sometimes aren't bought yet) and then you're done.

 

Sorry for the bad info I wasn't thinking at the time