rebore question

[curtis_5589]

i was wondering if the b18a1 can safely be bored .020 over, i know the manuals say only to bore .010 max, but i hear and have read the max u can go is .040 but most people don't boring to the extreme.

 

[BrokenTalon27]

.020 what? Mm, feet, miles?
You should be able to bore it over .020" and use the OEM over bore pistons. I had OEM ITR .020 pistons in my LSV and it was fine.

 

[hgocasca]

20 over is fine, you'll be cool bro

 

[Tam4511]

I think the limit is is a 85mm bore, stock is 81mm so you will be fine.
And I'm pretty sure that bore (.20) is measured in mm not inches.

 

[mirrorimg]

I think the limit is is a 85mm bore, stock is 81mm so you will be fine.
And I'm pretty sure that bore (.20) is measured in mm not inches.

Nope. Stock B20's (84mm) can be taken to 85mm (it may be a max of 84.5mm, so Im not positive), but not the B18.

The B18's max bore on stock sleeves (recommended by Honda) is 82mm. Thats .040" over. Beyond that, the strength of the sleeves is reduced. And the reason why B18's cant be taken to B20 bores is because the design of the sleeves is different.

I bored my block to 82mm, and since I have some heavy duty scarring in the cylinder walls, I am scrapping my current block and have another in the machine shop getting bored this week. Since 82mm is the service limit on the block, I cant hone out the existing one to rid myself of the scarring (nor do I want to try).

Just so you guys know the conversions.
.20" is ~5mm
.40" is ~10mm

.020" is ~.5mm
.040" is ~1mm

 

[hgocasca]

^^thank you for that, I'm doing some work soon, that will help

 

[BrokenTalon27]

I think the limit is is a 85mm bore, stock is 81mm so you will be fine.
And I'm pretty sure that bore (.20) is measured in mm not inches.

When I ordered my pistons it was in inches, oddly enough.

 

[hgocasca]

Mine too

 

[Prozon]

Typically with domestic rides they measure it in inches. (.020")
The metric thing was completely new to me when I got my Integra.
Good ol' Jason.

 

[hgocasca]

Yo kris, are those Hx rims?

 

[BrokenTalon27]

Typically with domestic rides they measure it in inches. (.020")
The metric thing was completely new to me when I got my Integra.
Good ol' Jason.

What I was saying is that when I got my ITR pistons I ordered them by the .020" over standard bore. Rings were purchased according to the same scale as well.

 

[mirrorimg]

What I was saying is that when I got my ITR pistons I ordered them by the .020" over standard bore. Rings were purchased according to the same scale as well.

That's how they are here, probably isn't the same in japanland. If you went to the dealership, you.would buy .020 or .040 over. Just the way the U.S. measures them I guess.

 

[BrokenTalon27]

That's how they are here, probably isn't the same in japanland. If you went to the dealership, you.would buy .020 or .040 over. Just the way the U.S. measures them.

Yup. That's what I did. When I told them I needed rings for 81.5mm ITR pistons they looked at me like I was on crack...lol