S10xGN

iTrader: (11)

Hi All,

A bud has a chance to score a complete iron 6.0L with 317 heads for $150.00. He knows it's got a "Jasper Engines" sticker on it so it's likely been bored already. He doesn't care about the rotator asm, it'll be swapped out for a 408" kit. What's the limit for boring an iron 6.0?

Thanks!

Russ

adam1803

iTrader: (65)

It depends on the block, i'd say anything over .030 or .040 should be sonic checked for thickness before boring.

elias_799

iTrader: (8)

it depends if you are going fi or na. for FI you will want much thinker cylinder walls then NA. that is why gm chose the ls3 over the ls7 for the zr1 vette. good luck

ice cream man

i just got a iron 6.0 that is .60 over so i will let you know how i goes haha

S10xGN

iTrader: (11)

One of the LS-1 books shows it to go 0.060" over, so we were wondering... He hasn't got possession of the engine yet, so we'll see what Jasper did to it. He's planning a low-boost budget twin-turbo setup.

Thanks All,

Russ

Gen414

iTrader: (38)

We know you meant .060 over and not .60 over

My block is .060 over and still has plenty of meat. Sonic test showed (and I am guessing from memory) @ .190 on thrust side. Depending on power levels will determine what is a "safe" thickness. Most machine shops like to see .200 when dealing with 750Hp or more. But you do hae to remember core shift, and just because this block or that block is thick enough, does NOT mean yours will. When trying to max a bore size, you need to have it sonic tested just to be sure. There were a few articles on this over teh last couple years, and there was one articl where they were sonic testing junkyard blocks and such just to show how blocks vary from one another. They found a block (and I can not remember which manufacturer) but it was STANDARD bore, and it like .100 thich. Yeah, .100. Thats it!! And I remember they were saying that that block was normally a block that could go .060 over or something like that. It was funny to think that at STANDARD bore, the block was unsafe already, and to think if someone actually tried to bore it .060 over what would have happened. WHOOPS Remember, that when you bore you only take HALF of the thickness off. So, say you have a cylinder wall that is .200 thick and you bore it .060 over, it will leave the cylinder .170 thick. Again, you are only take half away from one side of the cylinder.

Good luck, and the motto is: always sonic test

elias_799

iTrader: (8)

we are lucky that we have closed deck blocks unlike most of the jap **** out there.

awd2rwd

iTrader: (17)

<---- lq4 4.065

bigfatls6

iTrader: (34)

IF I were you and building a boosted engine I wouldn't want to go more than .030 over. Are the cylinder walls damaged or something?

S10xGN

iTrader: (11)

Don't know, he hasn't got posession of the engine yet... All he knows is it's a Jasper rebuild. Even if the block is trashed the heads, plates, fasteners, etc will still be worth the price. We just need the overbore info in case the block can be salvaged.

Russ