bandit1

iTrader: (12)

Ok back a bit, before the LS7 block was released it was said that it had some shoddy sleeves and was put together like *** from GM. Okay this was said by RED and Darton and there were those that said it was them trying to make money or promote their resleeved blocks, which may be but I dont think so, I think they may have gotten some earlier bad blocks. I have heard the earlier blocks used gray cast sleeves but that the later have the ductile sleeves this has been said by several builders. Some say they are nothing more than an LS2 block some say they have alot more to em then the LS2. Just looking for any new insight

Well I want to know now that its been out for a bit whats the general thoughts now. Was it a bad batch or are they crap. I am not asking about using the block for FI or large amounts of N2O. I am saying a nice 600 rwhp NA build is it a good strong block able to provide years of daily use and still see some track time. All things being equal I mean like mine has forged Mahle pistons, 1.5mm power pac rings, forged rods, forged crank, billet caps, clevite H bearings, forged crank, wet sumped with a double roller timing set, and a high pressure melling oil pump, all balanced and blue printed using a brand new LS7 block. I am not asking if something will go wrong and it will go boom cause that can happen to any engine. What i am asking is there any new news about the stock LS7 block. I keep getting mixed reviews and I want to know if i should be saving for a new block already.

I am just curious as to what some people are thinking about it, as i have heard of alot of guys making over 600 rwhp with a stock LS7 block and abusing it alot harder than i ever will and having zero probs, some I have heard are not having such good luck. Thanks in advance

Robin L

A lot of time has passed since some of those posts. A lot of people have built their combinations using the LS7 block. As everyone knows the LS7 block is unique to the LS7. Do a search there are differences. I have not heard of any problems with the blocks. Remember a lot of builders for the high horsepower engines go aftermarket rightoutof the gate. For a mild 600 HP 427 you should be OK.

The LS7 should hold up very well for your application. This is if your tune up NA and NOS is on track. You can ruin any engine if someone misses the tune.


Robin

bandit1

iTrader: (12)

Like I said I am going for around 600 rear wheel horsepower NA and it will all be tuned on the dyno and I have a wideband in the car as well to monitor it. I may shoot a 100 shot on top but still havent decided.

99blancoSS

iTrader: (115)

This is the info I got from one of the most respected builders on this site. Yes the sleeve can and has cracked under certain conditions. Forced induction and detonation!
Detonation ruins any motor. 600hp is not an issue. Even a 100 shot on top of it isnt an issue as long as it's tuned right. But that is true of any engine and nitrous or FI for that matter.
So really it was panic about nothing at all and RED and Darton have thier own agenda's.

bandit1

iTrader: (12)

Good to know thanks for the thoughts on the subject

KCS

iTrader: (20)

The sleeves are thinner to fit the larger bores in the same bore spacing as the other LS engines, so they are gonna be weaker and more susceptable to failure when making decent power.

As far as the sleeves being shoddy or put together like ***, they aren't all that great but they arent all that bad. Compared to a darton sleeved block, yes they are ***, but adequate.

The thing that seperates the LS7 sleeves from other aluminum blocks is the scallops at the bottom. They have a little extra length to them to help support the pistons when they reach BDC, without interfereing with the crankshaft's counterweights. This is especially important for strokes over 4.00", like a 4.100".

Just as a side note, I have seen a queer LS7 block recently. It lacked the scallops, but did have the provisions for oil squirters. I saw an iron 6.0L block like that too. Anyone know what thats about?

99blancoSS

iTrader: (115)

Point out one instance where one has failed in an application that didnt involve detontation and heavy FI.

Theory is one thing, practice is another.

Lets see some some actual results that prove your theory. I have stated that under FI application and detonation cracking in the top of the sleeve has occured. Not arguing that, thats what I was told by someone in the know(someone who would have been invloved in the repair or trouble shooting or knew the owner of the car in quesiton. In other words an extremely reliable source). BUT to suggest its inherently weaker isnt an accurate statement unless proven so. W2W (one of the many builders I have spoken to recently) has no problem using the LS7 block for a build. Are you saying they dont know what they're doing?

I even had a builder tell me that you can hone it to 4.130 or 4.135 safely, that the extended cylinder at the bottom makes for a bigger safe stroke. 4.250 OR something to that effect that I'm sure I butchered what he said.

If you've got proof then lets see some examples of failure, not just theoretical statements.

detonation ruins motors, get it tuned correctly. Or are you saying that ring wear will punch a hole in the sleeve.

KCS

iTrader: (20)

What are you smoking?

I never said anything about forced induction or detonation, and whether or not it would crack the sleeve. I said "decent power" (not limited to heavy FI or detonation) and by that I don't mean cam swap kinda power. I don't know what you expect for "proof", it's not like I have files of engines that blew up documented with whatever reason. It's just some information I have picked up through the grapevine, which makes sense considering a 4.135" hole is now in the same bore spacing as 4.030" and 3.905" holes used to be. Why wouldn't it be weaker?

I never said an LS7 block doesn't make for a good build, either. I have no idea where you got that. We go 4.135 on almost everyone of our LS7 blocks, unless one comes in at 4.118", and go no more than a 4.100" stroke without a seriously custom cam/barrel profile in the piston.

If anything, I was defending the LS7 block. I would definatley recommend the LS7 in this application for the reasons I sated. That was kinda the implication of the post.

ramairws6

iTrader: (33)

99blancoss.....there are numerous post on here over the last 3 years showing the exact proof that you are looking for. Take some time to check it out. Your also not realizing that the LS7 block is weaker also in the fact that the sleaves are not cast in like the LS1 and LS2 blocks. This makes a huge differance in forced induction of any kind! I'm not knocking the LS7 block cause I have one, but down the road I want to be safe with the liners when I'm spraying rather then taking a whole rotating assembly and parts out!! There are many cases documented of liners cracking under 500-600 horse N/A power and also cases of the liners cracking under nitrous stress. I know,I know, it's all in the tune right?! I don't deny that but is it worth the stress not being sure? Just resleave the LS7 and be done with it. Just added insurance and alot less stress! Traver

99blancoSS

iTrader: (115)

Ok I guess I misunderstood what you were saying kcs, apologies. I was told that FI and detonation is the issue or severely bad tuning (detonation) n/a, same as n2o. Added cylinder pressure and then the detonation and it cracks the top where it's unsupported.

I guess from your post I got that you were trying to say it will crack if your making decent power. I plan on making decent power and the company building it for me didnt see an issue with it at all. AM I being led astray? I'm not tuning it. LOL

ramair if your gonna re-sleeve the ls7 block then why not just get a warhawk?
If I was going FI I think I'd be looking at an iron block for the expense savings and putting the money into the top end and fi.

ramairws6

iTrader: (33)

They are also cracking verticaly down the liner not just around the top leading edge on N/A power. Believe what you want but if you do your homework alittle more in depth you'll come up with more answers.........but maybe they are answers you don't want to hear? Traver

99blancoSS

iTrader: (115)

Actualy I'm going by what the builder told me. It's his reputation. I told him what I plan on doing and he is building it accordingly. He seems to be some what of an expert at his trade and has the credentials to back it up. All I can do is go by that and trust his advice right?

I'm not affraid of any answer. I've got 13k just sitting here waiting to get dumped into my new engine. None of the builders I have spoken to had anything bad to say about the ls7 block. None. I gave them all their choice of block to use.

One thing I have learned on here is that there are many motors built and some fail. Not all the failures make it public. Some builders will blame the componant rather than the installer. Its their reputation. Are they going to come out and say hey we screwed the pooch on that one. Got the ring package and skirt height wrong on the piston because we didnt look at bdc or something techinical like that?

Its a very competative market, cutting through all the bullshit is really hard to do sometimes. And not all the facts are broadcast on this board.

Katech explained the sleeving processes and differences in the blocks very well.

ramairws6

iTrader: (33)

Good enough.......though you think your engine builder would tell you that the LS7 block is lacking since he is trying to sell you it for your build?! Got to look at it both ways.Traver

99blancoSS

iTrader: (115)

Well see thats the whole thing. He told me the pro's and con's and I picked the block. He would have used what ever block I decided to use, he doesnt make or stock them and has no vested interest in my block choice other than to not let me chose something that wont work and make him look bad. I could have gone with a sleeved 402 with longer sleeves but for my application it really wasnt needed the LS7 will work fine. Why spend the xtra money when it isnt needed. I have complete piece of mind with the LS7.

raceme@you'dlose.com

The LS7 block can't be too horrible with all the guys that are making crazy HP with them. Granted they may not be the best choice for FI or N2O but N/A I think they have held up pretty good. Hell GM sells them with a pretty good warranty so they can't be that bad. Just my humble opinion.

bandit1

iTrader: (12)

Now this is the kinda debate i wanted. Cause i too have a LS7 block and want to know that it will be ok if the tune is ok. I may use a 100 hp shot or a 200hp shot on top, I may never use it at all. I want around 550-600 rear wheel horsepower all NA thats very resonable on 427 cubes. Just want to make sure the LS7 block can handle it.

Ramair, we have chatted a bit before not about this but I did notice you making the claims of all the probs going on. Believe me I have used the search function and the only things i can find are the ones from before the LS7 was even avaliable to the public, and it was brought up by darton sleeves and RED, both in the market of either resleeving or making new sleeves. All I want is the truth and yes i can handle the truth lol.

I want to know exactly if the sleeves are cast gray or centrifugally ductile, I was told the first ones in the experiemental stages were in cast gray but in acual production are ductile. Ive been told by some builders they are ductile and i have been told by some their cast. Sucks why cant we get this info straight from GM Im sure of all people they know. Whats the benefit to either type of sleeve.

Next I keep hearing cracking of the sleeves but have yet to see this, like 99 is saying wheres the proof not the speculation?? Like he said whos acually gunna say we screwed up and built it wrong and thats why it cracked or we tuned it wrong and thats why, answer is noone is gunna say it. I searched and typed in LS7 block, Ive typed in LS7 sleeve, and I cant find much on the subject thats recent all of it that I find is before the release to public, years ago, if i missed something thats recent please guide me to it cause i must be typing in the wrong search words.

So maybe the faulty sleeving, the cast sleeves, were all fixed before they released it to the public?? Cause I can show MANY current, not years ago, threads showing 600 rwhp out of a stock bottom end LS7 with ported heads and a cam and exhaust. Look at Katech, who are probably the leading experts on what GM blocks can do, have beaten the crap out of their built camaro that uses LS7 rods rebushed, custom pistons, etc etc and a stock GM LS7 block.

Im not saying anyone is right or wrong but its really easy to listen to speculation especially from a place like Darton and RED both very good at what they do but whos to say what you acually got to look at, then what you were told you were looking at.

I tore my LS7 down just a few weeks ago to replace the L92s with my new LS7 ported setup and the sleeves, hone and all, looked brand new. Pistons looked great, doesnt burn oil or anything, has over 7-8 k on it and not light miles pretty heavy usage and quite a few runs down the track and it was making over 500 rwhp na with the old setup. I even sprayed on it a few times. I have alot into my setup and do not want to have to replace it anytime soon I bought the strongest parts I could think of, be sad to think I shoulda went with a warhawk block to compliment the rest of the powertrain.

ramairws6

iTrader: (33)

I won't get into a pissing match here and I'm definately not going to name names. I know quite a few engine builders who build sand dune engines out west that prefer the LS2 block over the LS7 all day long for durability. I know personally of the company that sleaves these blocks for GM and they are definately not cast in sleaves like the LS1 or LS2. Think about it, GM would go broke trying to do so many blocks for all the different applications? The LS7 is a low numbered production unit that is hand built and in that reason they do have a lot of time invested in putting it together. I'm not saying these blocks are junk, I'm just saying that if you want to spray or use any FI you probably will pay the price. The cheap Cast Iron liner just shatters upon impact! I've seen it, and I've done alot of research on this. Tell me this then, why do Katech use the resleaved LS2 block for almost all of there engine builds instead of the LS7 block? Must be a reason right? Hell the LS7 block comes with the Billet mains right off the bat,not the LS2.The LS7 block is good for about 650 horse.....even Katech has agreed to this. Traver

99blancoSS

iTrader: (115)

Nope,
Your right Traver. Your the expert. Are you an instructor at SAM? Do run a shop? What shop? Because your arguing not with but with the builder I chose. Now I know every builder thinks he knows whats best but the guy building my current engine now seems to have instructed a number of people working for and running shops on this board. As well as being the person who people send thier engines to when another shop hoses it.

This board is very political as well. I'll keep his name out of it but he is thought of as the best on this board, I'm sure he wont get into this thread as he's to busy and not about to waste his time.

I'll trust my guy until I hear from a reputable shop disputing his claim.
Guys are putting down 550+ all day long with LS7's, thats around or over 650 at the crank

bandit1

iTrader: (12)

ok good points all of em and I was not getting into a pissing match, its a conversation if people cannot talk without assuming that everything thats said is derogatory then we really have alot of growing up to do. I am only asking cause there again speculation, not factual.

You said (The cheap Cast Iron liner just shatters upon impact!) an you've seen it, when, where, who???? Details!! if i saw an LS7 liner shatter I would have been taking pics and posting up for all to see and try and protect my fellow LSXers before they wasted the money on an LS7 block.

Next Katech "does" use the resleeved LS2 block over the LS7 block for most its builds, well one good reason I can see is cost!!!!!!!!!!! LS2 bare block round 900.00 LS7 round 2800.00 so of course since they can do all the sleeving themselves it makes sense to me to save money anywhere they can and still provide a premium product. I also have seen Jason personally say he has done several LS7 cars and they are making well over 600rwhp and beaten on daily and he has seen no problems with the block what so ever. I havent seen where hes ever said it was good to only 650 hp though.

I never said the LS7 is a cast in sleeve its a dry sleeve and thats known, dont see the relevance with that. But like you said they have weak cast sleeves, who says, RED, darton, on some of the earlier blocks maybe?? What I am getting at is the stuff thats posted is of the block in the infant stage. I want to know what the thinking is now thats its gaining some maturity. Like windows 98 never buy the first version cause in 6 monthes they have a revised one out. I have seen a post by Jason at Katech where he said they were ductile sleeves so maybe they were changed in the public release blocks after they found the cast liners to be wanting. Just trying to get to the bottom of this, wish we had GM documentation to show whats what, I am sure there is a dam good reason the LS7 block, from whats been said just a resleeved LS2, is thousands more, maybe because it does have better liners, I know billet caps arent that much. Just my thoughts on it.

ramairws6

iTrader: (33)

Do you even know who I am and what I do? Didn't think so. You know nothing about me and I was just trying to help a couple peeps out. Didn't mean to ruffle any feathers. You do what you gotta do and I'll go my route, no harm done. At the end of the day I will be confident that if I ever spray or add more horse or stress to my motor the sleaves will hold. Traver