gearhead1186

iTrader: (8)

With price and strength in mind, which block would be the best to throw boost at. I've heard the ls7 cylinder walls are thin and wont hold boost as well as say the ls2.

Im looking for 700rwhp give or take so assume the psi needed to make that.

Darren P

iTrader: (1)

I think at 700RWHP you would be fine with either one

ChevyChad

iTrader: (50)

Well, just about any LS style block can hold 700rwhp without a problem. The iron blocks are probably stronger, but by the time you are making enough power to need something stronger than an aluminum block, the bigger concern is lifting the heads under boost. So then you will need either a warhawk or LSX block for the extra bolts for clamping force.

So having said all that, you can get iron 5.3L or 6.0L blocks for dirt CHEAP! You pay an 80# penalty over aluminum, but if that is not a concern for you, then look into an iron block. And try doing a little reSEARCH- there is tons of info in this section about block selection.

gearhead1186

iTrader: (8)

thanks guys...

i did a search and came across this.

https://ls1tech.com/forums/showthrea...ighlight=block

it seems like the general opinion is that aluminum will take 700-800hp and im looking for around 800hp. i guess ls7 is out since it has the thinest walls. im really looking to save weight and thats one of the reasons im looking at an ls block.

DownWithOPP123

Dude look at Mike brown and steve turley. Pushing the ls2 block WAAYYYY past 800hp.

ChevyChad

iTrader: (50)

Tiago went past 900 rwhp IIRC with a 347 aluminum block.

52172

iTrader: (2)

700 rwhp will not stress any ls series block. even a rehoned 98ls1 block.

LS1curious

Lest I read in sevral places those blocks are sleeved ?

52172

iTrader: (2)

the ls2 block is not resleeved unless it is stated so. the ls2 block will handle major power Mighty mouse is running one for quite a long time now without any issues. They will hold 1000 rwhp reliably. Once you hit that power level the clamping of the heads becomes the issue not the block.

gearhead1186

iTrader: (8)

thanks for the replies.. my goal is 800hp. no plans on going any further. now that we have the aluminum out of the way, is there any difference between the different ls that would benefit me?

52172

iTrader: (2)

doesn't matter if your talking 800 crank or whp you will be fine with either the ls1 or 2 blocks. The ls2 block is just slightly stonger than the ls1, but at you power level it does not matter.

ls1290

iTrader: (20)

There are many people make 700ish rwhp with stock LS1 and LS2 blocks. Once you start to push 800 to 850 the block start to become a lot more important. Many people has push 850+ rwhp with dry or wet resleeved LS1 and LS2 blocks. The block makeup is not as important as the decking, bluesprinting, deburring, etc. The block really needs to be prepped correctly to make that kind of power.

Keith

gearhead1186

iTrader: (8)

thanks guys.. so it seems as though the ls1, ls2 is the way to go with a 700rwhp goal.

however ls1290 said "Once you start to push 800 to 850 the block start to become a lot more important." I dont want to be on the brink. I dont really want to resleeve the block.

FootLbs

iTrader: (7)

LSX block if you got thah money!

ls1290

iTrader: (20)

A stock block LS1 or LS2 block is fine for 700 rwhp. It would not hurt that have the block decked, line honed, and blueprinted The main reason to resleeve the block is to get larger diameter cylinder bores.

Keith

gearhead1186

iTrader: (8)

gotcha.. thanks..

its for a 69 camaro so at first I just want to drop in the motor as it is for budget reasons.. then as money collects again I will either turbo or s/c it.

plus the ls being aluminum was one of its selling points for me.

I dont think my needs warrant an iron lsx block..

sworaz

iTrader: (13)

Helpful thread.

2001WS6Vert

I think you'll be fine with an LS7, I've had no issues with mine. Didn't that APS C6 Z06 make 1000whp?

InconFormula

iTrader: (7)

Yea we've pushed the ls2's way further than anyone else but these are not "stock" blocks, they have alot of work done to them to survive @ our power level.

I think a stock ls2 or probably an ls1 block would be fine for your build an iron block will work great also if you dont mind the extra lbs.

01ramair500hp

i went with the 6.0 iron block. .030 over