Oversized Pistons!
 

As you can see in my sig, I blew my motor.

I have yet to have my machine shop look at the motor, but if I can.
I am looking into boring out the sleeves and re-honing.

What are my option's for oversized piston's, ect.

What all will I need for my rebuild of course depending on how big my bore is.

I am completely clueless about bore sizes, ect.

Please help a lost soul looking to gain performance in a rebuild.

What parts would I need to buy, ect.

Thanks,
Bratboy90

Why do you want to bore stock sleeves, that's just asking for trouble all over again. If you're going to run aftermarket pistons you should have the zzp girdle block or a sleeved block IMO. You beefed up the pistons, what's the next thing that's going to detonate?

I hear of people over-bore all the time. Whats wrong with a slight maybe .020 max overbore?? I'm just wondering. I don't know much about that stuff. New to LSJ's.

Have you even looked at your sleeves? lol.

Save the money and get a ported head. Should be able to hit 300 with the other current mods. Add a tvs and bump it up to 350

One sleeve is damaged, weight my options to rebuild and gain H.P.
Check the pics on page #1
I'm going to say the sleeve is TOAST and can't overbore to fix. But I'm no genius. Prob will just replace sleeve and piston.

https://www.cobaltss.net/forums/prob...t-help-268005/

Anyone on here have a spare single diamond piston. LOL
Thanks,
Bratboy90

If you have stock sleeves I'd put stock pistons in and get a good tune lol. Like I said, you replace 1 weak link, what's the next? Sleeve. Sleeve is much more costly.

F he has a damaged sleeve it likely has to be bored at least 20 over to get rid of the damage. 20 thou is ~half the thickness of a finger nail.

or replace it lol. if you're gonna do it do it right and do the whole block, not throw pistons in cause they're the cheapest part and complain about the car when it cracks the sleeve.

i dont think we will go this option.

i just bored the stock sleeves on my lnf, i had light score on my 4th cylinder due to the piston blowing a hole in it, the machine shop told me i would be fine and i did wiseco 86.50 pistons

the main reason why people pop a sleeve on forged pistons is they dont check to see what the piston to cylinder clearance is or if the bore is out of round they just throw them in and run it you dont need a zzp block or dartons or bates the only way you need that is if your gonna get seriuos and start running shit on the ragged edge

i have they are .060 thick and shouldent be bored no more then .010 on a lsj block lnf i wouldent go past .020

you aint gonna make 300 just ona ported head and a m62

if the piston has the propper clearance and the bore is round it will live longer then stock pistons

thats good advice stock sleeves arent that expensive just dont heat the block to remove them they dont come out hard

In for the carnage of another grenaded LSJ...

if setup properly it will live ling and prosper but mst people wont spend the money to do it correct

Hes probably buying another block

Sub'd

Sub to his other thread. This wont be happening anymore...lol

Question
 

if i want to install 85 5 oversized forge pistons in where i currently have stock pistons which are 86mm will i need a bore?