I thought that the stock bore size is 81mm.... and .20over is 81.5mm?
https://honda-tech.com/zerothread?id=752257

Selling 81.5's and saying they're stock bore?

 

stock bore is 81mm

the guy either made a mistake or doesnt know what he's looking at.

 

Guess someone should inform him-- i tried to:

4:32 PM 2/3/2004) integranator: is that stock bore?? And what kind of compression would that bring me to?

(4:33 PM 2/3/2004) 94mugenintegra: stock bore, 8.5 to 1 on non-vtech B1bb

(4:34 PM 2/3/2004) integranator: oops, sorry read the whole post !! Thnx for the offer man, i'm kinda looking to go w/ stock bore

(4:34 PM 2/3/2004) 94mugenintegra: it is stock bore

(4:35 PM 2/3/2004) integranator: I thought 81.0 was stock bore

(4:35 PM 2/3/2004) 94mugenintegra: Stock bore on a B18b is 81.5mm so they are Stock bore

(4:36 PM 2/3/2004) 94mugenintegra: these are what you want if boosting with stock bore, there is none better, and they come complete ready to install

(4:37 PM 2/3/2004) integranator: well apparently I was wrong-- thnx for the offer tho.

 

Mr. Helms says 81mm

 

all b series motors have a 81mm born with the exception of a b20 which has a 84mm bore

 

made a mistake sorry 81 is Stock B series Bore