Steve - Race Eng

iTrader: (1)

Darton made the first set for me this week. They are available only for the LS1 block. The LS2 MID sleeve needs a different program. Be a while longer for that one.

I recommend the 4.200" sleeve not be installed in the LS6 block by the way. That block is pretty weak in the bottom because of the breather holes. The LS2 has similar breather holes but the wall is much taller between the cylinders because the coolant jacket has been raised relative to the earlier blocks.

Steve

Blitz

I agree - I don't buy the "LS7 is crap" stuff. It sounds like marketing to me, complete with pricing info.

See5

iTrader: (53)

I have read that the GM LS7 blocks have cast in sleeves as do the LS2

98Z28MASS

iTrader: (6)

Wow thats kinda crappy....hopefully GM corrects the issue as im sure there are gonna be plenty of C6 Z06 owners out there with similar problems if it is indeed not just an isolated incident. I honestly think GM should have just stayed with the LS2, except forged the bottom end and added a S/C as the production engine for the Z06 IMO. Im sure they are awesome engines the LS7's but man that just looks like poor craftsmanship.

2002_Z28_Six_Speed

iTrader: (19)

I am thinking that GM made it of gray cast due to the fact that it is the easiest and cheapest to produce. Not that it would be bad in the case of the daily driver.

Also, because it is not ductile it wouldn't be as likely to wrap and WOULD work fine if never subjected to anything more than average driving. Of course, metals fail and neck down at the S'ut point however they can be damaged before that be repetitive shocks that cause a progressive fracture.

You were worried about progressive fracture over the course of years, right? Because I don't see a single impulse just breaking a sleeve.

I think you made a good choice for the MATL on those sleeves. Would love to see a product picture. Very interested to see how they do!

Steve - Race Eng

iTrader: (1)

I posted these photos a few months ago but since you asked....

By the way, I don't normally post prices on this forum. The only reason I did was because someone asked.

Originally, it was published in SAE and other magazines, that the LS7 block was different from earlier blocks. The camshaft was raised, and had a larger journal diameter than the LS1, LS6 and LS2 blocks, etc.

Obviously this is not the case. John at Darton just wanted to point this out which is why he did the post. Since I did the actual work on the block I figured I could add some details about the block.

For those of you who want to run the stock LS7 block, Darton will make a ductile iron replacement for boosted or nitrous applications. The stock gray iron liner will probably hold up fine in a daily driver as someone else pointed out.

Ductile iron sleeves will not warp if properly installed. The block is what does the warping, not the sleeve. That is why I advocate stress relieving any new block. A used block will already be stress relieved through use so additional stress relieving is not required.

Steve

98Z28MASS

iTrader: (6)

I just dont get how GM could go cheap on the engine in an almost 80K car? I mean you can get an ls2 c6 vette for around 48-50K, and with that additional 30K you could make your own 427 for cheaper and still have a ton of money left over for a new tranny or rear end if needed. Not trying to play the ricer game with prices as I know the LS7 is a beast and the Z06 is a much more limited production vehicle, but I just would figure that youd get an exceptionally well built engine for that kind of money. I mean I would figure that even if they had to charge a little more they could throw in forged internals (forged pistons) and a much better sleeving material than that. Why go cheap on an engine that is going into your baddest production vehicle that is costing people around 80K? Doesnt make sense?

Slowhawk

iTrader: (12)

Probly 1 out of 3 potential Z06 buyer that calls me ask if we could do a FI setup on there car when they get it.By reading the info here it looks like resleaving the block and adding stronger rods is a neccesity(spell).Not going to go over well

BLU-BY-U

what about the Z06 owners simply staying NA? Like, at the very least, air intake, headers, more aggressive tune than stock? Maybe a cam swap? Would the stock gray liner hold up over time with a simple bolt-on packge (obviously, assuming a safe tune)? thoughts?

2002_Z28_Six_Speed

iTrader: (19)

I really don't think that GM "went cheap on it." It is not like it is made of sugar and will bust on a whim. I think you are a little overreactive on this matter. The stock sleeve is perfect for the job it was designed to do. If you plan on building up a motor, plan on replacing stuff. That goes for any motor. The LS7 is still a good motor and makes a lot of horsepower.

I know the car is 80K! But think of all the other work and materials they put into that car like the frame being a special AL alloy. I am sure you are getting what you paid for. The Z06 was rated a best buy wasn't it?

How many people are going to boost their Z06??? Very few compared to the number of people that buy them.

98Z28MASS

iTrader: (6)

Yea im not trying to say its a piece of crap by any means and i understand that you are getting a lot more than just a c6 vette with an ls7 engine, I just cant see not going with the best parts available for the engine, thats all. Its not like its an economy car, its pretty much a high 10/low 11 second track car made for the street, so id figure that they would use forged parts and top of the line sleeves, especially when it comes in at 80K. I mean I think all C6 Z06 owners would have been willing to pay 83-85K for the car if they had gone with better sleeves and all forged parts than saving 3K-5K and getting it around 80K, but again its just my opinion on the matter, thats all.

99Fbody99

Once again, It shows you not to believe everything you read in here or in magazines. Just becasue someone publishes something on speculation or has an "opinion" on something doesnt make it set in stone as being factual.

Dave

Also, How come Steve has not posted the benefits of the cast iron sleeves over the ductile?

Slowhawk

iTrader: (12)

If you have something factual,then please share?Steve did show some pic's and voiced his opinion from his hands on experience. You must have something to add that you dealt with hands on with this LS7 discussion?

99Fbody99

Just pointing out the obvious, Steve "Read in a magazine" or heard from a friend..then people formed a negative opinion.

Also, grey cast iron liners used are have significantly higher column stiffness and kill ductile iron in incometer testing.


Dave

Blue Angel

Over reaction, that's it.

GM beats the CRAP out of their engines during their durability testing requirements far more than anyone else ever will. This obviously does not include modifying the engine.

If you operate the engine outside the parameters covered in GM's testing and you blow it up, well, that's your fault. That's why warranties are voided when mods are done.

GM didn't design the LS7 to handle nitrous, super/turbocharging, or repeated detonation from poor tuning.

This engine has cast pistons to keep it quiet on startup, though most will bitch that forged pistons are better... those who will bitch are not the majority, and most of you them will never own one anyway.

Most people think that just because the rods are made of Titanium they are strong... you couldn't be more wrong. Material does not equal strength, the amount of material does. Titanium is strong for its weight, but unless you put alot of Titanium in there it's not going to be strong. The Ti rods in the LS7 are probably no stronger than the LS2 rods.

The LS7 is a pretty good engine, the most powerful N/A V8 ever released in a production car. One guy screws up a nitrous install on one and everyone thinks it's crap because it blew up. Come on...

BTW, how come I can buy a resleeved LS2 from Race Engine Development for $2,700, and Rapid Motorsports sells the same thing for $4,000???

jrp

iTrader: (16)

umm, the "magazine" was the SAE papers...

where are the metalurgy test that prove the greater stiffness over ductile iron? please bring facts to the table instead of hearsey...

Bill Reid

iTrader: (14)

I'm still waiting on facts regarding accusations that the LS2 and LS7 blocks are one in the same (with factual disections of said blocks)... which started this thread. Ya, I'd like to see some proof BOTH ways... at LEAST regarding common street apps which this forum caters to... NOT all out race apps that may require extensive block work. And I'm sure we'll see some proof soon enough that the LS7 is PLENTY strong enough, as released from GM, to support horsepower levels that most here only dream of. GM comes out with a block that clearly encroaches on a sleeve manu's business along with a machines shops labor business... and this is the best they can do... crap on the very company that makes businesses happen... let alone this forum. GM has not yet announced pricing and availability of the LS7 block (let alone the L92) although speculation runs rampant. Rest assured that when they are released, along with the Warhawk... there will be other options than sleeving an existing block. Competition for market share is great... brings out the best/worse in all of us.

Bill

jrp

iTrader: (16)

well you are in possession or have access to an ls7 block from the crate motor your doing a project out of correct? why dont you put your money where your mouth is and send darton your block and they disect it and measuer it spec to spec against the ls2 blocks they have in the shop. then when you proven wrong they ship you back your new paper weight...

darton did not purchase the block to create bad press or speculation. a customer destroyed the sleeve in his block with a 300 shot of n2o. said customer then contacted a shop for options on how to proceed with a new build. the shop then contacted darton to R&D a new sleeve to replace the one that was destroyed by the n2o. steve removed the sleeves to see what he had to work with and what kind of sleeves the block would accept. Steve did the R&D on the ls2 specific dry sleeves that darton produces and the specifications needed to bore the block out. so he knows the specs of the ls2 block inside and out. during the inspection of the ls7 block he put two and two together because the specs came out to be the same as an ls2 sans the larger bores.

and from GM's cost perspective it makes perfect sense to use and ls2 block and just resleeve it for the larger bore. some people are just under the illussion that GM gave them the holy grail of blocks with the ls7. however the block seems to follow suite with the rest of the materials used for the bottom end.

Bill Reid

iTrader: (14)

Not gonna happen... wouldn't dare give a block to someone in the business to make GM's products look bad. Thanks for your nut hugging suggestion though.


Ya, so an idiot smokes his block and it MUST be repaired... I put 2 and 2 together, unlike you, and it was a PERFECT opportunity for 2 small businesses that support this forum to capitalize, perhaps, on members looking for big cube direction.

Nobody is under the illusion that GM created the holy grail... yet you are certainly trying to contribute to it. The burden is not mine... like you would like it to be. Certainly you would like the comsumer to have the burden... not forum vendors, correct?

I have copied and saved everything on this thread... it will keep everyone honest in the future...

11 Bravo

iTrader: (3)

Steve has been installing, desigining and training other people how to sleeve engine blocks since I believe the 1970's. That is why we listen to him. What are your credentials?