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Discussion Starter #1
What's the consensus on the max over bore when rebuilding an LSA? I have gotten several different answers from reputable Machine Shops that specialize in LS engines. They have varied from you can only go to 4.070 to you can all the way up to 4.100. When I spoke to a tech at Weisco I was told you can only go up 4.095. I'm not looking to bore my motor for power or anything like that. Just asking to gain knowledge in the event that need to bore my block in the future. The two recent low oil pressure threads have me thinking.

Thanks.
 

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4.070, the sleeves are very thin and you dont want to bore out more then that, consensus is buy a new block if you need anymore.

I did some reading on getting the blocks resleved, but it didnt make much sense for the money it would be better to go lsx if your after more power or buy a new lsa block if you want to replace the stock motor. RHS Dart and companies have some aluminum options with bigger cubes.
 

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It's not JUST what you can safely bore the sleeve to - it's also keeping in mind power goals.

Most people upgrade to a stronger block because they also increase power on the rebuild.

Thin sleeves and aluminum LSA blocks don't do well with high HP applications.

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Discussion Starter #4
That’s what I was thinking. But why would several shops including Weisco say you can take it out to .30 over? If I owned a machine shop I wouldn’t want to put my reputation on the line boring it out to much, leaving the customer with a ticking time bomb.
 

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That’s what I was thinking. But why would several shops including Weisco say you can take it out to .30 over? If I owned a machine shop I wouldn’t want to put my reputation on the line boring it out to much, leaving the customer with a ticking time bomb.
So they can sell you a second set of pistons. Hahah

I've spoke with shops before that say they are comfortable working with the LSA then dont know things like they have oil squirters or how thin the sleeves are. My guess is you spoke to someone who thought you were talking about any ls 5.3 or 6.0 block.
 

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That’s what I was thinking. But why would several shops including Weisco say you can take it out to .30 over?
Because you can. That's not the same thing as saying it can handle 1000 HP without pushing a ton of blowby through the ring lands as the bores go out of round.

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Discussion Starter #7
I’m starting to rethink my cam swap, I’m already at 4.070. I’m probably better off building a new short block for the cam I have on order. It would also allow me to build a stroker. Then I have the original motor as a backup or for the day I decide to sell my car
 
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