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-   -   Bore and sleeve (https://www.subaru-svx.net/forum/showthread.php?t=23248)

sicksubie 12-15-2004 06:41 AM

Bore and sleeve
 
Has anybody attempted to bore and sleeve an SVX? I plan on strengthening up and refurbing my entire engine over the next year with a goal of eventually running 15-20 lb of boost.

SilverSpear 12-15-2004 07:07 AM

I was wondering if this will lower the compression ratio...

SVXer95 12-15-2004 08:09 AM

Quote:

Originally posted by SilverSpear
I was wondering if this will lower the compression ratio...
No.

SilverSpear 12-15-2004 08:11 AM

Quote:

Originally posted by SVXer95
No.
thanks

mohrds 12-15-2004 09:17 AM

Quote:

Originally posted by SilverSpear
I was wondering if this will lower the compression ratio...
It could, but realistically not.

In order to decrease compression, the sleeve would have to be thinner than the amount you bore the cylinder out. You start boring that much and you'll probably get into some coolant passages.

Doug

SVXer95 12-15-2004 09:49 AM

Quote:

Originally posted by mohrds


It could, but realistically not.

In order to decrease compression, the sleeve would have to be thinner than the amount you bore the cylinder out. You start boring that much and you'll probably get into some coolant passages.

Doug

You still wouldn't change compression ratio by changing bore. The volumes would be different, but the ratio would stay the same. CR is a affected by height/length of the combustion chamber, not volume of diameter.

When a small glass is half empty a big glass of the same height is half empty, but with more beer.;)

Pure_Insanity8 12-15-2004 10:36 AM

Re: Bore and sleeve
 
Quote:

Originally posted by sicksubie
Has anybody attempted to bore and sleeve an SVX? I plan on strengthening up and refurbing my entire engine over the next year with a goal of eventually running 15-20 lb of boost.
This is exactly what I was thinking for Michael's supercharger kit specifically (but any force induction application in reality). I was thinking this would be worth loosing a bit of displacement in order to gain sidewall strength for higher boost numbers... instead of what Michael was thinking (as in closing the deck). I'd much rather keep my water jacket.:D Maybe he will look into this after he is done with the kit.

EDIT: I wasn't actually thinking about boring it first... just putting in a thicker sleeve.

mohrds 12-15-2004 12:34 PM

Quote:

Originally posted by SVXer95

You still wouldn't change compression ratio by changing bore. The volumes would be different, but the ratio would stay the same. CR is a affected by height/length of the combustion chamber, not volume of diameter.

When a small glass is half empty a big glass of the same height is half empty, but with more beer.;)

er, not exactly.

compression ratio formula is:

(one cylinder swept volume + deck cc + head cc)/(deck cc + head cc)

If you are increasing the volume (cylinder swept volume) it will alter the compression ratio.

Granted the change will be minimal, but it will change.

Doug

red95svx 12-15-2004 01:08 PM

Quote:

Originally posted by mohrds

If you are increasing the volume (cylinder swept volume) it will alter the compression ratio.


I agree. If you change volume, CR has to change.


Dave

oab_au 12-15-2004 02:55 PM

reducing the swept volume?
 
Boring and then sleeving the block will change the ratio. But why? You will then need different pistons, so why not use a piston with a lower ratio, and leave the block as it is. Boring and sleeving will leave the block weaker than it is now.

The liners are cast in, they can't move, pressed sleeves can and do.

Harvey.;)

mohrds 12-15-2004 03:51 PM

Re: reducing the swept volume?
 
Quote:

Originally posted by oab_au
Boring and then sleeving the block will change the ratio. But why? You will then need different pistons, so why not use a piston with a lower ratio, and leave the block as it is. Boring and sleeving will leave the block weaker than it is now.

The liners are cast in, they can't move, pressed sleeves can and do.

Harvey.;)

I didn't say I wanted to do it, I was just clarifying another post.

:)

oab_au 12-15-2004 04:47 PM

Re: Re: reducing the swept volume?
 
Quote:

Originally posted by mohrds


I didn't say I wanted to do it, I was just clarifying another post.

:)

I didn't think you were Doug,:) I was also, just clarifying the clarifacation.:D

I have seen pressed in sleeves, pulled down by the piston, to be smashed be the big end. :(

Harvey.;)

TomsSVX 12-15-2004 07:31 PM

ok i have been wondering for a long time. What exactly is closed deck? i have heard ideas floating around but i want to know for sure. Does this have anything to do w/ the water jacket surounding the entire cylinder? i had my heads off and realized that there is no support for the cylinder walls at the connection to the head.

THAWA 12-15-2004 07:39 PM

a closed deck looks almost like a full block of metal with holes for the cyl and holes for the coolant passage. An open deck is pretty much cyl liners in an empty block of metal. This should help understand: http://legacycentral.org/library/literature/deck.htm

You do have support for the cylinder walls on the horizontal plane, but not on the vertical plane.

TomsSVX 12-15-2004 07:56 PM

so is there any way for us to convert to closed deck? Is it as simple to make supports without disrupting coolant flow?


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