It's detonation (extreme cylinder pressure spikes) that cracks the sleeves where they are very thin at the top like Steve says and it is real. With no detonation they seem fine so well tuned NA should be pretty safe and NOS is obviously the worst as NOS is very unstable and always has some detonation going on it seems.

 

^ Just the response I was looking for. Thank you very much.

 

Like I said, I have Darton Seal Tight dry sleeve blocks out there holding a thousand to the wheels. Build and tune the engine right, make sure you have sufficient cooling capacity and you will be fine on pump gas to that power level. Above that I recommend the MID wet sleeve.

Stock LS7 blocks hold up fine with race gas. You must keep the stock block out of detonation or you will split a wall.

It is a lot easier for me and cheaper for you to sleeve the block before it cracks if you intend to run pump gas with high compression, boost or nitrous.

I sleeve many brands of engine blocks, not just GM LS blocks. The Toyota 2 liter 2ZZ engine used in the Lotus is holding 750 to the wheels with the Darton Seal Tight dry liner. That's 2 liters, not 7.

My MID wet sleeved block 3.2 liter Acura FX Motorsports NSX Time Attack car (Cricket Wireless Sponsored) makes 900 flywheel horsepower from 3.2 liters. They won the last four races and set new track records at each of those races.

Note that these two examples have four bolts around each cylinder. In fact, all the block makes I wet sleeve with Darton MID sleeves have only four bolts around each cylinder. It's all in the building and tuning!

To answer the question on the difference between wet and dry liners. Dry liner does not come in contact with coolant. It fits in the aluminum bore of the block and depends on that aluminum bore to keep it round. A wet liner does away with the aluminum wall and is in direct contact with the coolant. Wet liners have a much thicker cylinder wall than a dry liner and do not depend on the block for support to keep them round regarding piston side thrust or cylinder pressure. Examples, the Darton wet liners used in diesel tractor pull hold over 125 lbs of boost. Nissan 3.5 liter MID sleeved V6 2,200 hp on methanol with 60+ lbs. of boost. Honda 2 liter MID sleeved four banger 1,450 hp on methanol with 45 lbs. of boost. Ford 5.4 liter MID sleeved GT40 2,200 hp (not sure on the boost on these).

Steve

 

Perfect....thanks for the time Steve.

 

So cost for cost, I think most builders are quoting about the same cost, wuld a LS2 Darton be better than a stock sleeved LS7?

I am asking for a pure pump gas, NA application.

 

Thanks for the info about the dry and wet sleeves....but which is used for what engine type...what I mean is why would one use a dry sleeve vs. a wet sleeve. I'm assuming that a dry sleeve being thinner allows for a larger bore right? but wet sleeve blocks have better cylinder cooling right? So for a street motor wet sleeves are better(for cooling) but if you want the cylinder size then you have to go dry sleeve.

 

What would be best for a high boost application on a budget build?

 

cubic inches is king in my book 440

 

so im thinking about buying an ls7 block and buying all the parts i need one at a time. what would be best for a boosted application with an ls7 block? On a buget.. Lmao.

 

Does not compute...

 

Couldn't you just use a cast crank, buy some forged rods and pistons...and make a safe 700 RWHP.

.

 

Scat's 4.250" stroke cast crank for big blocks is rated at 700hp, I don't think I'd even think about pushing one the size of an LS to that power level. If it goes, everthing goes.

 

Won't a cast LS1 crank work in an LS7 block?

.

 

Well I'm already at 600rwhp on a near stock ls6 engine.

I was wanting to build a bigger engine. No replacement for displacement.

 

resleeve an LS2 block and go crazy on it with power.

 

Correct, Darton sleeved LS2 is the way to go here. I just got another cracked cylinder LS7 block in today to repair.

Steve

 

Well if a resleeved ls2 block is better than a ls7 block whats the max CI i can go on the ls2? I was wanting to try and atleast get a 427 CI..

 

nice thread,

how much rwhp gain going from 427 to 440 ?

my guess would be no more than 10-15 rwhp.

 

A 427" is no problem 4.125" bore 4" stroke. I have done several blocks for 454" 4.185 bore 4.125" stroke. Max. cubic inch for the dry liner normally aspirated would be 468" which would be 4.185" bore 4.25" stroke.

I like to keep the stroke at 4.125" for street use to get some longevity.

Steve

 

Hey Steve thanks for all the advice.

I have a paxton novi 2000 and w/e engine I would build would have it bolted on. With that being said my hp goals are around 1000. Maybe more in the future, but I like to only have to do things once.

How much would a resleeved ls2 440 block cost? How much power could that hold with boost?

What about a stock ls7 block?

Or what other blocks could be used?

I'm trying to stay away from spending a whole lot of money if thats at all possible.I know i can spend around 4k and get my ls6 to be a forged 383 stroker, but I was wanting a lil more cubes than that. Thanks in advanced,

Brett