Another Re-Sleeving Question

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Senior Member
For starters we're talking about an LS engine.

I'm not sure what the stock bore is on the LS, but I've seen a few people talk about boring it out to 84-86 mm (around 2.0 litre).

What is involved in this process?
I know you're going to have to take it to a machineist and bore it out plus resleeve it.
What is the cost?

What additional parts would a person have to buy?

i.e. new pistons...? anything..
and for quality parts, whats an average cost?


Mad scientist
Stock bore in an LS = 81mm, with an 89mm stroke. Boring to 84mm will give you 1973cc, and boring to 84.5mm will get you 1997cc (or 1998, can't remember right now).

Boring would involve milling out some of the block casting, then pressing in new sleeves with the larger bore. If you don't want to resleeve, you can just mill out the stock sleeve and live with thinner walls. I wouldn't suggest this though.

84mm is the largest that I would go for a boost application- 86mm is getting into some pretty thin sleeve walls for a B block, although I'm sure you could source some more exotic sleeve materials to get it to hold together under boost. An 86mm bore with the 89mm LS/B20 stroke will get you to about 2.1L, but not quite.

The only extra parts you would need are larger bore pistons and rings- all the rest of your old hardware will still work. If you're really picky, you can reshape your head's combustion chambers to match the larger bore, but it's not totally necessary.

Let's estimate:

Bore/resleeve: $1200-1500
Pistons/rings: $600

That's it.


Senior Member
If you're really picky, you can reshape your head's combustion chambers to match the larger bore, but it's not totally necessary.

That would just be like boring the top end to match the bottom end right?

Whats the disadvantage to not doing this? It seems like it would be a good idea if you're going to do the bottom end, to just do the top at the same time.


Senior Member
if ur going to resleeve, is there a specific company (the makers of the sleeves) that someone should go with or is it all the same thing?

Canuck 93 Civic Si

Senior Member
if you reshape the head, you will get a little more cylinder volume and better volumetric efficiency because of the smoother transition from head to block. Kinda like matching your head and intake manifold when you port and polish.


Senior Member
So... (dont mind my l33t paint skills).


(if you didn't bore out the combustion chamber?)

Canuck 93 Civic Si

Senior Member
if what your trying to illustrate is that there will be a lip where the head meets the block, then you are correct. Because the dome of the cylinder head will have an 81mm diameter it wont match up with your larger bore and you will get turbulent flow in this area. If you match everything up, you will get better gas flow in and out of the cylinder.


84mm is as large as you want to go with boost, even with sleeves. 84.5 is pushing it, 85-86 and you just have paper thin sleeves