Rb22det Safe To Bore 4mm?

[impultion]

Hi,

I have been offerd 82mm Custom CP pistons and cometic head gasket. Anyone ho has experience on boreing the cylinder from stock 78-82mm? Are the walls thick enough or DOES the kit require cylinder sleeves. Nobody has ever answered this question, and I am a little sceptic to bore 4mm over. Afraid the walls will be to thin to handle any boost.

This seller tells me its safe and no prob. to have 82m pistons fitted.

And are there any diffrence on the cylinder walls on the early and late RB20DET engines?

Thanks for any replys,

Thomas.H

www.edgeperformance.no

Edited May 23, 2007 by impultion

[Adriano]

You would have to get the block sonic tested, or fitting sleeves isnt heaps expensive, just depends on the cost of the sleeves, they can be exxy in some sizes

[1400r]

check the rb24 thread think the guy already has pics of his bored out not sure how big he went though

http://www.skylinesaustralia.com/forums/in...20&start=20

Edited May 23, 2007 by 1400r

[impultion]

Thanks, Hi went with 83mm pistons. 5mm over. I will hear with him wht hi has done with the block.

check the rb24 thread think the guy already has pics of his bored out not sure how big he went though

http://www.skylinesaustralia.com/forums/in...20&start=20

[deant1]

boring out an engine and then not inserting sleeves = engine rebuild in the near future.

[impultion]

Hi, are you sure?

This guy bored 5mm over. 83mm on his RB20 block

Murravis:

Hi Mate,

The block i have used is from a 93 r32 gts-t

The walls are still pretty thick, i got them checked when they did it and they said there fine, There is no need to sleeve the block, i was going too but the machine shop said there is no need too.

We took mine out 5mm and there fine, if tomie has made pistons to do the rb22 or rb24 conversion at a bore of 83mm they must be fine.

on another note is that your engine bay below?

Cheers

Cameron

boring out an engine and then not inserting sleeves = engine rebuild in the near future.

[deant1]

Well a guy i work with is an engine reconditioner by trade and he's done allot of boring in his life. He told me RB blocks are bullet proof when untouched, never seem to wear much at all (especially RB30 blocks). But once they are boared it's a very different story, much faster wear etc. using inserts will prevent this happening.

As most people will know Cast iron only has a hard outer skin (add to this nissan uses gas nitriding to harden the surface further) and the inside is very very soft. Generally the skin only has about <2mm of 'hard' surface. If you want to take of 5mm from the diamater that's a 2.5mm deep bore which is most likely the castings skin gone or very thin at best. Hence the reason people use inserts because they provide the skin again.

Machine shops will gladly do the work i'm sure but don't expect your block to last as long. personally id go for inserts especially on a bore that big.

PS: Incase i confised anyone. it's not the strength of the wall's that i'm talking about it's the hardness which will casue premature wearing of the block. You don't want that!

Edited May 24, 2007 by deant1

[impultion]

Hi,

Thanks for that information. Do you know of anyone ho has forged pistons and rods to the RB20DET in stock?

Thomas

Well a guy i work with is an engine reconditioner by trade and he's done allot of boring in his life. He told me RB blocks are bullet proof when untouched, never seem to wear much at all (especially RB30 blocks). But once they are boared it's a very different story, much faster wear etc. using inserts will prevent this happening.

As most people will know Cast iron only has a hard outer skin (add to this nissan uses gas nitriding to harden the surface further) and the inside is very very soft. Generally the skin only has about <2mm of 'hard' surface. If you want to take of 5mm from the diamater that's a 2.5mm deep bore which is most likely the castings skin gone or very thin at best. Hence the reason people use inserts because they provide the skin again.

Machine shops will gladly do the work i'm sure but don't expect your block to last as long. personally id go for inserts especially on a bore that big.

PS: Incase i confised anyone. it's not the strength of the wall's that i'm talking about it's the hardness which will casue premature wearing of the block. You don't want that!