and also inspector, that was with a stage 1 cam in it ..now it has a stage 3, and 150 shot. i bet it would drag the paint off of that orange car now!!!

 

Come on John I am just kidding with you don't get all upset it wasn't what the thread was about I just like giving Parker a hard time about Lance' car. And besides I don't think it will do it even with a stage 50 cam. The 150 shot I am sure helped it a lot, but if you talked to Parker about the little run we had you would find out that it was very bad for the new ZO6 not even close.
Jeff

 

thats funny ...no i was just saying that it runs good for a cam only car with a little gas on it ....and yes i know your car hauls ***....we need to meet up im ready to play around on the streets again ...it just seems like its a lot more fun on the street..

 

Yeah I hear you I have still been playing here and there. Just give me a call sometime and we'll get together.

 

I didn't read the whole thing but LS7 blocks are "aftermarket" in that GM sends LS2 blocks to a supplier who do the resleeve for them.

You know how much it would cost to recast an aluminum block for such a low production vehicle? If it was an actual casting you can believe dealers would have them because they'd need to sell a shitload to make up.

I bet the ONLY reason the Z06 got a LS7 is because the block gets resleeved and even that is alot of money for a OEM to spend on a motor. That makes it a half way decent business case and puts the problem in the suppliers hands.

I bet the LS7 is easily one of the most exspensive NA motors for an OEM due to the block process save maybe for the BMW M motors.

 

What about the LS2 factory sleeves?
- How far can you push them before getting into a danger zone?
- Are they grey iron or ductile iron?
- Are they cast-in or pressed-in? Which is better and why?
- What is column stiffness?
- What is an incometer test?

 

I have an LS7 block pre-machined by GM before the sleeves went in. The OD is within 3 thou of our LS2 dry sleeve OD. I guess we did something right!
The LS7 & LS2 block are the same, just bore size is different, thickness throught the block is the same. A LS2 or LS7 stock block will take the same amout of power IMO

 

 

For a guy with a block and a bad sleeve (LS7 - 4.125) right now sleeving is the only option. When the LS7 block becomes available over the counter, considering price, it may be cheaper to buy a new block than to resleeve. Will a dry sleeved LS7 block be just as good if not better than as originally delivered? Thats a given when done right.... with cost increase being relative to power goals. The LS7 block, as prepped from the factory needs to prove itself in the market before sleeve manu's and machinests start bagging it without proof... pretty much all I was trying to say... WITHOUT bagging on resleeved blocks, resleeving products, or the process.

Can you confirm through non-destructive sonic testing that cylinder wall thickness (minus sleeve) is more/less the same between the LS2 and LS7? How about webbing structures? I was under the understanding there were supposed to be improvements down there... be nice to confirm it.

Bill

 

My sonic testing shows they are the same thing

 

Darton has offered a replacement repair sleeve for the LS1, LS6 blocks for some time - years. I will not use it to resleeve the entire block. It doesn't have a large enough flange diameter to keep the sleeve from dropping in the bore over time. It is strictly for those with a cracked stock liner wanting to save the block by repairing one cylinder.

The Darton LS2 dry sleeve was designed from the beginning to eliminate any chance of the sleeve dropping. This was done by increasing the flange diameter to 4.550" which is greater than the bore spacing of 4.400". This sleeve requires CNC equipment to keep the center to center distance exactly at 4.400" during the boring operations to install the sleeves. This because the flats on the sleeves must mate perfectly else the sleeves will be knocked out of round.

Unlike the earlier LS1 LS6 blocks, the LS2 has no coolant channel between the bores. The coolant channel caused a very thin aluminum wall between sleeve and coolant on dry sleeved LS1 LS6 blocks. Because of core shift, many blocks were too thin and would crack during service. This led to coolant leaking into the crankcase which along with the sleeves tending to drop made for a less than perfect assembly.

We developed the MID wet sleeve to overcome these shortfalls with the LS1 LS6 dry sleeve installations.

The LS7 block uses a 4.300" outside diameter sleeve. I specified the LS2 dry liner be made with a 4.325" outside diameter in the piston thrust area without ever seeing an LS7 block. The LS2 Darton dry liner has two body diameters with the lower diameter set at 4.275" making it possible to retrofit a LS2 dry sleeved block with MID sleeves should one decide to build a blower or heavy nitrous engine using the same block core.

The LS2 and new LS7 replacement sleeves will safely go to 4.150" bore. Actually the LS7 sleeve will have a lower body diameter larger than the LS2 dry sleeve making it possible to bore to 4.190". The LS2 and LS7 blocks are identical so it is possible and I will install the new LS7 sleeve in LS2 blocks for those wanting to go to 4.190" max. bore size. I recommend the dry sleeve for under 1,000 hp applications. Above that level you want to use the MID sleeve for its superior strength.

Note that the LS2 LS7 dry sleeves also incorporate sealing grooves in the lower body diameter. By using a small amount of Loctite sealing compound during assembly, virtual o'rings are created in these machined grooves. This is intended to keep oil from creeping up between the block and sleeve - something no other sleeve manufacturer has to my knowledge. Also notice the crankshaft counterweight cut out at the bottom. This allows greater sleeve length, now 1/8" longer to allow better skirt support for strokes to 4.25". By the way 4.190" bore X 4.25" stroke yields 472 cubic inches. With the availability of large port high flow LS7 and ET Performance high port heads, it is now possible to get enough air into an engine that large.

Note that this post was originally posted by Darton to enlighten people about the the LS2 and LS7 block castings being very similar if not identical. It is therefore possible to build your own LS7 dry sump engine since all the LS7 bits and pieces will bolt up to an LS2 block which can be sleeved to LS7 bore size and beyond.

Steve

 

Allow myself to quote, myself...

No one has answered this question yet... If R.E.D. sells a Darton MID Sleeved LS2 for $2,700 with no core charge (using a new stress relieved GM LS2 block), then WHY does the "same" thing cost $4,000 from Rapid Motorsports?

$2,700 is a steal for a block that will handle over 1000 hp and support 472 inches, especially considering their knowledge and looking at the cost of the alternatives. Even the new Warhawk block doesn't hold a candle to that, and the Warhawk will require goofy intake manifold spacers for those without the budget for a sheetmetal intake... between the intake spacers and the taller deck, will this cause hood clearance issues on 'Vettes? What about cowl clearance on F-Bodies?

If the LS2 bottom end will handle more power than most people will make on pump gas, it looks to me that the Warhawk may only be required for race fuel duty.

Any comments???

 

The price I quoted was for the block, sleeves, installation, and decking.

The block still needs to be bored and honed, studded and possibly (most likely align honed). I do that work here for some people, time permitting.

I sell blocks to several sponsors and I am sure they sell them in different stages of prep. Your best bet is to contact Mikey and the others I mentioned previously and ask them what else they do to the blocks.

Steve

 

Very good write up! I was kinda looking forward to see how these things were going to be, but it seems that GM went the way of cheapness and we've got ourselves another 10bolt story LOL!! I'm glad I'm going to do a Warhawk block when I switch setups.

For the people who are saying this is a advertising gimmick.. get out of hear.. You all have low post and probably don't know a thing about LS1s! Darton and Steve are VERY good people and don't need to slander GM to get buisness. Fact of the matter is that the sleeves GM used suck.. You probably doubt the fact that the new z06s can't road race because GM was too cheap to buy a different rotor for them. Also that the new Z06 doesn't just randomly blow up, unless you take it in for warranty or put a aftermarket cam and valvetrain it.

The durability test are to prove that the motor will last for a long time, not how much power it will take, etc. They leave that to companies like W2W, Katech, etc.. If they did durability test for beating on cars the 10-bolt would have never been installed on the F-body, because last time I checked that was factory tough! lol

 

BTW the main benefit of the Warhawk block is the extra bolts per cylinder.. For you 10,11,12,13sec people that doesn't mean jack. But when you try to run 26psi on a 106 and your cyl heads now sit 4" off your block.. you start to get pissed.

W2W had problems with pressurizing the cooling system on Mike Morans car, just like everyone else. They luckly did not lose any power due to it, but its the fact that if the head can be held down it will be more reliable over time.

 

Steve,
How about the Darton shop iin New Albany, Indiana. Would you recommend them for sleeving and assemblying a 427 out of someone's LS2 block? Had not heard them mentioned here and just wondered.

 

Just to summarize, what is the strongest block setup for a big bore stroker? - LS1 with MID sleeves?

 

I consider the LS1 block with MID sleeves to be the strongest of the factory blocks. This because the LS1 is the only non windowed main web block in the series.

Steve

 

Why would GM want to engineer an engine capable of 1000hp if their goal was to build a 500hp Vette? The car would cost more and still have the same performance.