Hey everyone, I�ve hit a snag in my build and was hoping someone with some more knowledge could give me some advice.

I took my engine to the machine shop and it�s showing �.005 out of round�. The guy said that I could drive it with that but it�d be a better engine with it bored.

from what I understand the max bore is .010. If I�m already .005 out of tolerance then I�m assuming I can only bore another .005 to clean it up. My pistons are showing that I am .004 under STD.

My question is if I am planning on running Boost, would it be better to buy new pistons and not bore it. Or would it be better to bore it to the max .010 and risk them thinning it too much? I�m assuming new pistons are required regardless.

thanks I�m advance for any help.

 

What engine?

 

5.7 aluminum block. It came out of a 97 corvette.

 

I know there wasn't a lot of wiggle room on the early LS1 engines. How far I can't say. Hopefully someone like KCS or Helicoil with waay more machine shop experience can chime in.

How much boost are you planning on running? It may be easier and cheaper to get a 5.3 block and boost the **** out of it.

 

I would be afraid of any boring on an early LS1 block. Cylinder walls are THIN.

 

I agree with Liljay. Depends on how much boost you want to throw at it. Ring seal is your friend, so don’t skimp. You want the cylinder as close to perfect as possible.
Ive read here on Tech that people have went .010 on an LS1 and then I’ve read some on Tech say that .005 is absolute max. I’ve never had an LS1 to a machine shop, so I’m no help at all here.

 

I wasn�t planning on running very much boost at all. I was originally planning on doing a 5.3 build specifically for boost but ended up going this route instead.

 

That's kinda what I was thinking G but there are a lot of people that have more experience that i do.

Nobody "plans on" running much boost at first......Depending on your goals and budget..If you are trying to get a car together, get it running with boost I would probably dingle hone the LS1 block, slap it back together and get the car running.

Just my .02

I would rather have a running car than something sitting in the garage for a year while I build it. Life happens and **** takes 5 times longer than expected unless you have deep pockets.

 

Might ask him to make a .005 pass on it, if it's .005 out, doing a .005 would bring it right in doing a .010 would actually cut beyond the .005 out.

If he can clean it up at .005 run it.

If not... I don't know. You'd actually have to run it and see if it were going to be an issue but the max recommended is .005 over

You could always back up and go with a 5.3, or if it's in the budget buy a new LS2 block and run your crank in it and your covers on it. Sell off the LS1 stuff to help cover it. The bare LS2 block is right around 1400. Not cheap but not horrible

 

Thanks everyone for the advice. I decided to throw it together as is. I haven�t found a shop that does a lot of LS motors so I�m hesitant to try and clean it up. I�ll let you guys know how it goes.

 

Good idea!

 

First off, if your shop hasn�t been in an engine very much, that�s been out for 22 years now, find another shop. I�m serious. Secondly, the bores are out of round .005. That�s a considerable amount. Will it run like that? Sure. Will it use oil because of ring seal? Sure. Are you giving up power and reliability? Sure. Make noise and cause piston life to be shorter? Sure.
You said you wanted advice, here�s mine. At the BARE MINIMUM have the block honed .005�. Might cost you a buck eighty plus piston/ring set, which you can pick up at WS6Store for cheap.
I think putting it back together as is, is a bad idea, unless your dumping the car.

 

A JY 5.3L will cost less than the machine shop fees on the LS1. And it'll be better for boost.

I'd just do that.