Slow98TA

I'm looking at what all it is going to cost to build another motor for my car. The block that is in the car is a 125k mile unit, and I am debating on if I should have this block re-sleeved if I can do that, or spending the extra cash on a new LS6 Block. I believe TSP has them for around $700, and talking to a guy I know who owns the local performance shop (DC Motorsports...was Nitro Dave's Performance) he said that he would go with the ls6 block due to better oiling, and the fact that it is "said" to make more hp? Is this true? I mean, I'm not wanting to cut any corners in this re-build or go cheap...but is it REALLY worth the extra $700? The combo isn't going to be anything very wild..stage 2.5 5.3 Truck heads, TSP 231/237 cam, and an LSX intake. So would it be worth it? Any insight is apprecaited.

Thanks,
Jason

Jason99T/A

iTrader: (21)

I personally would just find a used, LS1 block for around $300 and put the money elsewhere.

Jason

Steve - Race Eng

iTrader: (1)

The LS1 block is substantially stronger than the LS6 for any type of performance application. A new LS6 block is not worth the money. Further, your old block (or any good used LS1 block) is nicely aged. When I machine a new LS6 block for MID sleeves, it must be sent out for stress relief $$ to stabilize the casting after roughing it out or it will warp all over the place after a few heat cool cycles when put in use.

Steve Demirjian
Race Engine Development

Slow98TA

So, will re-sleeving the block completely cancel out the fact that it's "nicely aged"? Or, are you speaking in areas other than the cylinder walls?

DenzSS

Or a 6L iron block. All of the blocks need a fair amount of work to be wothy anyway.

Steve - Race Eng

iTrader: (1)

I've found there is no problem with used LS1 blocks or used LS6 blocks during or after machining for sleeves. Any machining will put stress in metal, however the used blocks stay pretty straight and need no stress relief. If you are a fanatic and want everything as perfect as can be stress relief won't hurt even on a used piece.

With a new unused LS6 block the outer block walls (they support the sleeves) will move in or out a few thousandths after machining out the original cylinder liner and wall due to residual stress in the casting. If that stress isn't reduced the outer block walls will move a lot more when the engine is put into use causing the cylinders to go out of round. You will end up with an oil burner or worse.

Stress relief cures the problem with new blocks but it runs $200 additional for the process. That covers removing the block from the CNC after roughing, cleaning, stress relief, and re-setup on the CNC for finish machining.

In any event, an LS1 block is much better suited to high output due to it's stronger main webbing (no large "breather" holes).

Steve Demirjian
Race Engine Development

FEAR THE LS1

iTrader: (1)

Does the LS6 block supply better oiling to the lifters?

I heard that for a big power/high rpm setup the LS6 was the way to go so you can maintain good oil pressure throughout the motor.

Thoughts?

Lee

Steve - Race Eng

iTrader: (1)

The lifter oiling is identical on these engines. The claim is the breather holes in the crankcase free up power at higher revs. I think the main reason the holes are there is to save aluminum at the foundry.

Olds came out with a similar block for their 403 motor a few years back. Engine builders used to shun those things like the plague. I'm not about to start opening holes in the main webbing of my non LS6 race engines to make power.

Steve

Steve - Race Eng

iTrader: (1)

I've got an iron LS block coming in shortly to see if it can be sleeved with MID type sleeves. Down side is weight of course. It will cost more to sleeve since iron doesn't machine nearly as well as aluminum. If the iron block can be sleeved it will be a real strong piece.

Steve

BIGBOS

I got my 6.0L iron block for $600 bucks

Heretic

What do you charge for a Darton sleeved block?