Generation III Internal Engine - MAX bore for a LQ4 block

what is the absolute biggest bore you can get out of a 6.0 block?

ill do at least a half fill on the block to help keep it together.

I think it is 4.060" safely.....might be a hair bigger, but not sure.

I think it is 4.060" safely.....might be a hair bigger, but not sure.

thats just what i dont want! haha

of course i want it to hold together for a while but im not too concerned about longevity or anything like that.

I've seen guys go to .065, making theirs a 6.2 liter. My engine supplier, who is one of the largest in the country (claims to be the largest) says these iron block 6 liters can go out to .090, with no problems. Personally, I would consult a sponsor of this site, before I made any decisions.

To bore that much, it is wise to get the block sonic tested. Why, because of core shift and the fact that all blocks are certainly not alike. (Even from same casts).

Mitch I dunno if a 60 over LQ4 is gonna take 30psi :lol:

Predator-z hit it on the head.

Nobody can "tell" you how much you can overbore. They can only say typically. Take the block to a machine shop for sonic testing. They can tell you how thick the thinest part of the cylinders are. Then they can make a decision on how far is safe. Core shift can make cylinders thick on one side and thin in the other.

Mitch I dunno if a 60 over LQ4 is gonna take 30psi :lol:
haha, if this happens it wont see any bost, or at least thats not the plan. just a budget NA setup.
Predator-z hit it on the head.

Nobody can "tell" you how much you can overbore. They can only say typically. Take the block to a machine shop for sonic testing. They can tell you how thick the thinest part of the cylinders are. Then they can make a decision on how far is safe. Core shift can make cylinders thick on one side and thin in the other.

thanks for the info. this is just in the rough planning stages so i was just wanting to get an idea of what can and cant be done.

i just built one at 4.065
and im working on mine at 4.085. with stoke crank for 380ci.:usa:
more than confient it will hold. plan on 7000+rpm shifts.

Should be fine. If you get it sonic tested, post some results.

is the Gen III and Gen IV 6.0 blocks the same for bore capabilities? cause i want to put a Gen III block in to replace my LS1 eventually and was wondering if i could punch it out to 416 vs just a 408.

It is always preferable for street to keep the motor square or under.

is the Gen III and Gen IV 6.0 blocks the same for bore capabilities? cause i want to put a Gen III block in to replace my LS1 eventually and was wondering if i could punch it out to 416 vs just a 408.

Look at it this way.....build your 408, run it for 100,000+ miles, then when it needs rebuilt you will have room in the block to rebore end get a 416

Look at it this way.....build your 408, run it for 100,000+ miles, then when it needs rebuilt you will have room in the block to rebore end get a 416

sounds like a plan

is the Gen III and Gen IV 6.0 blocks the same for bore capabilities? cause i want to put a Gen III block in to replace my LS1 eventually and was wondering if i could punch it out to 416 vs just a 408.

I too would like to know, how the Gen III and IV compare ?