bore size

[Crix]

Iam using a 94 B18b1 block with oversized pr3 (usdm) b16 pistons. What would the bore size be? 81.25?

 

[erebunicrx]

usually they are 81.5. where did you buy the pistons? they sholud know.

 

[posol]

81 is std from honda
81.5 is std overbore from honda

 

[Crix]

whats the stock bore size of a ls? plus the .25 os pr3's? Do I just add? stock would be I think 81mm bore so 81.25? I just need to know so I can order the GE lsvtec conversion kit because its comes in differnt sizes. Basically my setup is a ls block with .25 os pr3's. Which kit would need to be ordered?

 

[brian11to1]

Yes stock bore of an LS is 81mm. so if you over bore it .25 its gonna be 81.25. good luck.

 

[posol]

81.25mm oem honda parts simply don't exist.

allow myself to quote myself.

81 = std bore oem
81.5 = std overbore oem

 

[Crix]

ok iam confused now, I bought .25 oversized pistons from honda dealer. I work there so I get good discounts. Honda doesn't sell .50 os pistons. They don't even reconmend going .30 over. I sent my block to engine lab and gave them my pistons and ls block. They fitted the pistons to factory tolerances. Which I would think would be 81.25mm bore if its a .25 over pistons. Ive already test fited on of the pistons and everything is well.

What do you mean std. overbore is 81.5?

 

[Crix]

you mean for that motor (ls) they don't come .25?

 

[nfn15037]

I think he left a "2" out of ".25". All OEM oversized pistons are .25 over.

 

[phunky.buddha]

81.25mm is the standard B18 oversize according to my Integra service manual. The allowable bore range is 81.25 to 81.27mm, with a maximum taper of 0.05mm between the top (6mm below deck) and bottom (6mm above bottom of sleeve).

 

[Crix]

ah ok.

 

[brian11to1]

so your bore should be 81.25