4.1 bore on an LS3 block?
4.1 bore on an LS3 block? Just wanted to see if anyone has heard of such. Got my new issue of GMHTP the other day and they showed a road race 422 build that supposedly used an LS3 block punched out to 4.1 with a 4.0 stroke. They just punched it out .040 without doing any trickery to make it work 
. This was an endurance type of build making 700+HP. I was under the impression that a light bore cleanup was as far as the block would safely go.
Im running a stock displacement LS3 and planned to build a 416-418 down the road when I got bored with the setup. If I can safely go out to 4.100, I will ! If the block will take it, Im a fan of the bigger bore, just for the increased head flow.
What gives? Is it legit?
. This was an endurance type of build making 700+HP. I was under the impression that a light bore cleanup was as far as the block would safely go.Im running a stock displacement LS3 and planned to build a 416-418 down the road when I got bored with the setup. If I can safely go out to 4.100, I will ! If the block will take it, Im a fan of the bigger bore, just for the increased head flow.
What gives? Is it legit?
TECH Regular
Joined: Dec 2011
Posts: 448
Likes: 2
From: SoCal
Just wanted to see if anyone has heard of such. Got my new issue of GMHTP the other day and they showed a road race 422 build that supposedly used an LS3 block punched out to 4.1 with a 4.0 stroke. They just punched it out .040 without doing any trickery to make it work . This was an endurance type of build making 700+HP. I was under the impression that a light bore cleanup was as far as the block would safely go.
Im running a stock displacement LS3 and planned to build a 416-418 down the road when I got bored with the setup. If I can safely go out to 4.100, I will ! If the block will take it, Im a fan of the bigger bore, just for the increased head flow.
What gives? Is it legit?
. This was an endurance type of build making 700+HP. I was under the impression that a light bore cleanup was as far as the block would safely go.Im running a stock displacement LS3 and planned to build a 416-418 down the road when I got bored with the setup. If I can safely go out to 4.100, I will ! If the block will take it, Im a fan of the bigger bore, just for the increased head flow.
What gives? Is it legit?
Travis
Looking at the liners in my factory bore L92 block, I'd say no way. On this block, the liners are cast in slightly off-center resulting in one edge of the liners being < 0.060" and the opposite side being ~ 0.120"...
People have in fact opened them up to 4.100. Caution needs to be taken in the core used but it has been done. There only removing .0175 material per side so a little core shift is ok.
Yea, from what I gathered from the article, no sleeve work was done, just torque plate bore job on a factory LS3 GM block. What got me was, this isn't a 1/4 mile at a time build. It a road racing deal that sees a lot of RPM for extended time. Brutal conditions for a thick wall block, much less a max bore factory block. It gave me the impression the factory block is stouter than it gets credit for.
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4.100" on a ls3 block is definitely not ideal. 
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Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
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Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
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Verdad Gallardo I have heard of it being done. But you always hear it won't and cain't but the interesting thing is that the guys who have done it, there motors are living.
I have yet to see one of these overbore engines cylinders crack or have major issues. I have seen more failures from poor machine work and tuning that take out even stock standard clearanced blocks.
I remember when folks were saying .030 was about as far as you could go with the 6.0 iron blocks, now .060 is very common.
Makes for good bench conversation though.
I have yet to see one of these overbore engines cylinders crack or have major issues. I have seen more failures from poor machine work and tuning that take out even stock standard clearanced blocks.
I remember when folks were saying .030 was about as far as you could go with the 6.0 iron blocks, now .060 is very common.
Makes for good bench conversation though.
Thread resurrection for updated info. Max bore/stock sleeved LS3/L92's are becoming more popular.
https://ls1tech.com/forums/generatio...92-engine.html
https://ls1tech.com/forums/generatio...92-engine.html
