427-454 ci ls7's...
The Z06 factory LS7 engines are all dry sump.
The LS7 block oiling system however is identical to any of the other aluminum LS blocks and can therefore be built up either wet or dry sump depending on other components, ie crank, oil pan, oil pump, front cover, etc.
The LS7 block oiling system however is identical to any of the other aluminum LS blocks and can therefore be built up either wet or dry sump depending on other components, ie crank, oil pan, oil pump, front cover, etc.
__________________
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
Steve Demirjian
Race Engine Development
Oceanside, Ca.
760-630-0450
web: www.raceenginedevelopment.com/
e-mail: race-engine-development@***.net
I wasn't going to reply to this but three LS7 blocks with cracked cylinders in one week prompted me to submit a reply.
Two folks contacted me directly last week, one with an LS7 with four cracked liners and another fellow with one cracked liner. Unfortunately, once the block cracks, it is very difficult to weld and repair. Try welding a crack once antifreeze gets in there. The only sure repair is to remachine the block for the MID liners. This is the only way I will repair any future blocks with vertical cracked sleeves. The third block I mentioned will be repaired this way. It is an actual block out of a Z06 not something put together from a bare block. The other two guys are going to purchase new blocks and throw the dice once again. The cost of MID sleeving the block was prohibitive for them.
I had Darton come out with the dry Seal Tite liner to offer a lower cost method of not only beefing up these blocks, LS2 LS7, but increasing the bore size as well. The Darton Seal Tite ductile iron dry liner will and has gone to 4.190" bore in these blocks. I have never had a block come back with a broken Darton dry liner. I do blocks for Mikey at Rapid, Alan Futral, and Erik Koenig to name a few. The material is at least three times the strength of the original equipment gray iron liner.
The LS7 blocks I have repaired in the past all have had cracked liners due to detonation, not due to dropped valves. In fact, one of the guys above had his crack during tuning on the dyno. Some LS7 blocks have issues with poor machining at the factory or core shift in the cylinder walls themselves. I have one block here with walls that are paper thin on the side that cracked. Other problems are due to cutting too large a chamfer in the aluminum block right under the sleeve seating flange. This leaves gray iron sleeve unsupported right where it needs support the most. The result is the sleeve cracking around the circumference two hundred thou down just under the flange seating area. Those blocks I can repair with the dry liners because the aluminum is not cracked. Sleeves with vertical cracks always crack through the aluminum block wall.
So bottom line, keep the power levels reasonable, tune to keep out of detonation if you are running the stock block. Otherwise it is much less expensive to sleeve the block with the Darton Seal Tite dry liner in the first place than to repair it after failure.
The LS9 engine does not use the LS7 block because they were not reliable at the 638 hp power level. GM went to a smaller bore block to allow a thicker gray iron liner to get the required strength. I saw one of these cars the other day, very nice indeed!
The reason I see these cracked blocks is because folks contact me directly or Darton when they have a problem. So they end up here regardless. Our two businesses go back to the mid seventies by the way.
My primary business now is sleeving blocks mostly imports, some main stream some exotic. To give you an idea on the main stream stuff, Darton dry liner Toyota 2ZZ 2 liter four banger engine 750 to the wheels. These blocks end up in the Lotus, most end up going to Europe. Not one problem at that power level. I have done at least a couple of dozen this year alone. The Viper dry sleeved blocks I do are well over twelve hundred with the dry liner. The wet liner Viper blocks are north of two thousand. The Viper guys are getting pretty serious by the way. I am currently working through a back log of some thirty plus 6.1 liter Hemi blocks which I am wet sleeving with MID liners. Nice block but very heavy! Same exact deck height at the LS blocks and the same exact main bearing bore diameter. Some coincidence.
I do dry sleeve a lot of LS blocks. I have done several in the past year for some of the better NHRA stock and super stock cars. NHRA has allowed the guys to run the LS2 block sleeved down to LS1 plus .070" bore size. Improvement, a tenth under the record first time out using the same exact pieces except for the block. The Pro Stock guys wouldn't be sleeving their blocks if there wasn't an improvement in performance to be had.
Steve
Two folks contacted me directly last week, one with an LS7 with four cracked liners and another fellow with one cracked liner. Unfortunately, once the block cracks, it is very difficult to weld and repair. Try welding a crack once antifreeze gets in there. The only sure repair is to remachine the block for the MID liners. This is the only way I will repair any future blocks with vertical cracked sleeves. The third block I mentioned will be repaired this way. It is an actual block out of a Z06 not something put together from a bare block. The other two guys are going to purchase new blocks and throw the dice once again. The cost of MID sleeving the block was prohibitive for them.
I had Darton come out with the dry Seal Tite liner to offer a lower cost method of not only beefing up these blocks, LS2 LS7, but increasing the bore size as well. The Darton Seal Tite ductile iron dry liner will and has gone to 4.190" bore in these blocks. I have never had a block come back with a broken Darton dry liner. I do blocks for Mikey at Rapid, Alan Futral, and Erik Koenig to name a few. The material is at least three times the strength of the original equipment gray iron liner.
The LS7 blocks I have repaired in the past all have had cracked liners due to detonation, not due to dropped valves. In fact, one of the guys above had his crack during tuning on the dyno. Some LS7 blocks have issues with poor machining at the factory or core shift in the cylinder walls themselves. I have one block here with walls that are paper thin on the side that cracked. Other problems are due to cutting too large a chamfer in the aluminum block right under the sleeve seating flange. This leaves gray iron sleeve unsupported right where it needs support the most. The result is the sleeve cracking around the circumference two hundred thou down just under the flange seating area. Those blocks I can repair with the dry liners because the aluminum is not cracked. Sleeves with vertical cracks always crack through the aluminum block wall.
So bottom line, keep the power levels reasonable, tune to keep out of detonation if you are running the stock block. Otherwise it is much less expensive to sleeve the block with the Darton Seal Tite dry liner in the first place than to repair it after failure.
The LS9 engine does not use the LS7 block because they were not reliable at the 638 hp power level. GM went to a smaller bore block to allow a thicker gray iron liner to get the required strength. I saw one of these cars the other day, very nice indeed!
The reason I see these cracked blocks is because folks contact me directly or Darton when they have a problem. So they end up here regardless. Our two businesses go back to the mid seventies by the way.
My primary business now is sleeving blocks mostly imports, some main stream some exotic. To give you an idea on the main stream stuff, Darton dry liner Toyota 2ZZ 2 liter four banger engine 750 to the wheels. These blocks end up in the Lotus, most end up going to Europe. Not one problem at that power level. I have done at least a couple of dozen this year alone. The Viper dry sleeved blocks I do are well over twelve hundred with the dry liner. The wet liner Viper blocks are north of two thousand. The Viper guys are getting pretty serious by the way. I am currently working through a back log of some thirty plus 6.1 liter Hemi blocks which I am wet sleeving with MID liners. Nice block but very heavy! Same exact deck height at the LS blocks and the same exact main bearing bore diameter. Some coincidence.
I do dry sleeve a lot of LS blocks. I have done several in the past year for some of the better NHRA stock and super stock cars. NHRA has allowed the guys to run the LS2 block sleeved down to LS1 plus .070" bore size. Improvement, a tenth under the record first time out using the same exact pieces except for the block. The Pro Stock guys wouldn't be sleeving their blocks if there wasn't an improvement in performance to be had.
Steve
So are they using a magic LS7 block?? I myself have a had a few bouts of detonation and had no probs as of yet. Like I said normally when there is a big problem with some sort of GM product thats had problems, we here on LS1tech hear about it. I have heard of the CTSV lifter probs and even had 2 fail on me hence while I changed to LS7 lifters. But as I have made it clear "YOU" are the only one bringing these problems to light. I cant find a single thread where someone has come on here saying hey my LS7 block cracked why. This includes the corvette forum as well, zero issues that I can find and search is my friend.
So your telling me out of the 1000's of LS7blocks out in use that none of these guys that you have done their blocks for which you are saying is significant, meaning there is a problem with these blocks, not one of these guys is a member on either board?? If they are, not one of them comes on to say something about it. If I crack a sleeve Ill be the first to admit I was wrong but I have yet to see anything wrong with the LS7 block up too 1000 fwhp. Beyond that yeah it may prove beneficial to sleeve it but with sleeving comes its own problems. Now if you do a search problems bout sleeves cracking, coolant leaks, dropped sleeves and the list goes on. Heck heres one from a block you installed sleeves on, ( https://ls1tech.com/forums/showthrea...+block+cracked ) which you never responded too. But I cant find a single thread that says anything about an LS7 block cracking for no reason. I have seen a few cracked sleeves from a dropped valve and even one that sprayed 200 shot of N20 and had a solenoid problem and went lean and detonated so bad it cracked the sleeve and destroyed the piston. But if this is such a huge problem I would expect to see a few others that supported the claim.
Not trying to start an arguement just trying to see what your basing your claims on. Have you checked the build dates on the blocks could it be a year problem??? Maybe theres a certain year that had problems. I just want to know for my own curiosity so I know what to look for on my engine in case something happens. GM is pretty quick to list certain problems in their TSP's and so far no cracked sleeveis among them but there is a rocker bearing notice, spring problem notice, and a few others but no nothing about sleeves cracking.
Launching!
Joined: May 2008
Posts: 282
Likes: 0
From: va beach
I am building a n/a 408 with lq9 block, trick flow heads, big cam and new converter, fast 92/92 yada yada from virgina speed. it will hae 4.0 inch crank what hp numbers should i be looking at at the rear wheels?
Eric @ HKE is building an engine for me now using a new LS7 block. I'm sure if there was any major concerns he would have mentioned it when planning my build.
My build will be strictly NA but I do plan to beat the **** out of it doing the 1320 boogie.
My build will be strictly NA but I do plan to beat the **** out of it doing the 1320 boogie.
I doubt anyone is saying the liners in these engines just fall apart, but they are not anywhere as strong as a re-sleeved block.
also there is a big big difference between gm's version of 'no problems' and yours. these 638 hp motors have to meet requirements (100,000 'blower' miles with a warranty etc)....which means much more conservative than you or i would do.
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Verdad Gallardo I'm a member of both boards and I have an LS7 block with cracked liners sitting in my shop. I've seen the LS7 block crack exactly like the first LS1 block I saw cracked back in '00. Just because you didn't read it on the internet does not mean they don't exist.
I doubt anyone is saying the liners in these engines just fall apart, but they are not anywhere as strong as a re-sleeved block.
I doubt anyone is saying the liners in these engines just fall apart, but they are not anywhere as strong as a re-sleeved block.
If you go and reread my post you will see that I did say that a properly resleeved block with darton sleeves is stronger than a stock block.
Hey I have a block here with cracked sleeves sitting in my shop too know what caused it a valve dropping. Just cause you have one doesnt mean anything i NEVER said it doesnt crack i said the reasons for cracking are usually something much different than "ow they are weak GM cast gray iron" An acually yes that has been the consensus is that these blocks are cracking liners for no apparent reason even under stock power. That has been said by Steve and darton in a few posts
Bandit, Bandit, you just won't give up...................I guess till you see a cracked liner in your block!! Then I suppose you won't want to post it here or over at the Corvette Forum cause they'll be just too much egg on your face. He!He!He! And when the hell have you hit the 700 FWHP #?? I have a full out 441 and I don't even have that.................
With nos I have alot more than that and "IF" I crack a liner Ill post it up for all to see but you and I both know as long as I keep my tune nice it wont happen, so stop nutswinging cause you bought into the LS7 sleeves being weak propaganda LOL hahaha. At least I can explain the nasty looking crap on my face ......its egg, whats you excuse, he spat it out LOLOLOLOL???? I am just stirring the pot this is one of those its all an opinion thing I just was getting a bit bored, LOL
With nos I have alot more than that and "IF" I crack a liner Ill post it up for all to see but you and I both know as long as I keep my tune nice it wont happen, so stop nutswinging cause you bought into the LS7 sleeves being weak propaganda LOL hahaha. At least I can explain the nasty looking crap on my face ......its egg, whats you excuse, he spat it out LOLOLOLOL???? I am just stirring the pot this is one of those its all an opinion thing I just was getting a bit bored, LOL
Erik is a friend of mine, and I value his advice and knowledge. What exactly you two discussed is probably different than what is probably being discussed here. No one is saying that the liners in the LS7 just fail instantaneously with too much power. There are very powerful LS7's out there to prove that, but YOU have no experience with how it got there. Find out what the deck height ended up being on those engines and you may get a little surprise. Then again, companies like Katech and LPE, who have deep rooted business ties with GM, probably get the creme of the crop in engine blocks. Probably not what most of us get.
I, like Steve, have seen a bunch of these LS7 blocks have problems with the liners. One engine detonated and cracked two liners, but it was so light that the pistons were still virtually re-useable. That same engine, like many others, actually dropped it's sleeves .003". I have machined LS7 blocks and had the sleeves drop just from the torque plate being bolted on. Standard procedure now is to deck the block, and then bolt on the torque plate. WHEN the sleeves drop, we deck it again, and repeat until the sleeves stay put. This process works pretty well, unless we use a domed piston.
It's just that the sleeves are WEAKER. Not only that but they are pressed in with the machining precision of a company that rips out 150 blocks a week for production. There is potential for problems. Fortunately, yours is fine and you are happy with it. I hope it stays that way, but I have seen these problems first hand and its hard to argue with whats sitting in front of you.
You really act like a typical "internet warrior" whenever this sleeve stuff comes up. It's understandable, I guess, considering you own one and are worried about your investment, but to basically spit in the face of the people who deal with this issue day in and day out is rather silly.
Erik is a friend of mine, and I value his advice and knowledge. What exactly you two discussed is probably different than what is probably being discussed here. No one is saying that the liners in the LS7 just fail instantaneously with too much power. There are very powerful LS7's out there to prove that, but YOU have no experience with how it got there. Find out what the deck height ended up being on those engines and you may get a little surprise. Then again, companies like Katech and LPE, who have deep rooted business ties with GM, probably get the creme of the crop in engine blocks. Probably not what most of us get.
I, like Steve, have seen a bunch of these LS7 blocks have problems with the liners. One engine detonated and cracked two liners, but it was so light that the pistons were still virtually re-useable. That same engine, like many others, actually dropped it's sleeves .003". I have machined LS7 blocks and had the sleeves drop just from the torque plate being bolted on. Standard procedure now is to deck the block, and then bolt on the torque plate. WHEN the sleeves drop, we deck it again, and repeat until the sleeves stay put. This process works pretty well, unless we use a domed piston.
It's just that the sleeves are WEAKER. Not only that but they are pressed in with the machining precision of a company that rips out 150 blocks a week for production. There is potential for problems. Fortunately, yours is fine and you are happy with it. I hope it stays that way, but I have seen these problems first hand and its hard to argue with whats sitting in front of you.
Erik is a friend of mine, and I value his advice and knowledge. What exactly you two discussed is probably different than what is probably being discussed here. No one is saying that the liners in the LS7 just fail instantaneously with too much power. There are very powerful LS7's out there to prove that, but YOU have no experience with how it got there. Find out what the deck height ended up being on those engines and you may get a little surprise. Then again, companies like Katech and LPE, who have deep rooted business ties with GM, probably get the creme of the crop in engine blocks. Probably not what most of us get.
I, like Steve, have seen a bunch of these LS7 blocks have problems with the liners. One engine detonated and cracked two liners, but it was so light that the pistons were still virtually re-useable. That same engine, like many others, actually dropped it's sleeves .003". I have machined LS7 blocks and had the sleeves drop just from the torque plate being bolted on. Standard procedure now is to deck the block, and then bolt on the torque plate. WHEN the sleeves drop, we deck it again, and repeat until the sleeves stay put. This process works pretty well, unless we use a domed piston.
It's just that the sleeves are WEAKER. Not only that but they are pressed in with the machining precision of a company that rips out 150 blocks a week for production. There is potential for problems. Fortunately, yours is fine and you are happy with it. I hope it stays that way, but I have seen these problems first hand and its hard to argue with whats sitting in front of you.
Typical of people who have no solid evidence to start the name calling. First off I am no "internet warrior". Ill say this straight to you, eric, steve, easter bunny or whoever if asked face to face. An internet warrior is someone thats tuff only behind a screen, which I am not trying to act like, I simply want "proof". So sorry the pursuit of some sort of intelligent insight is seen to you as being an "internet warrior".
Is Steve the only one that knows this??? Maybe, maybe not but throwing it around like its fact is not right either. An yes it has been stated that these are cracking under stock power go back and reread some past posts by Steve and darton.
Then you say Eric is a good friend, ok I think Eric is a great guy an really knows his stuff I value his opinion highly. But when i spoke with him he had no qualms with using the stock LS7 block for me and even has said the same recently to a few that have posted here in this thread. Being they are getting engines built for themselves from Eric using the stock LS7 block right now that kinda goes against you saying he has changed his views.
If you are referring to my comments to Travor (ramair) he is a good friend and he knows I am joking with him. This has been a discussion piece for he and I quite a few times and its the same here. I am not saying anyone is wrong. Have I said the stock block was just as strong as a properly sleeved one???? No quit the opposite. Have I said that the liner in the LS7 is stronger than a darton?? No again the opposite. I have simply implied that coming from someone that is respected in the community (Steve) dont try and start a scare. I have no worries about my block at all, I did at first which is why I started researching this whole situation. The block issue is acually not an issue at all and yeah I can see a few having a problem but as for the majority their fine.
Ow and I love the comment about LPE and Katech getting the cream of the crop. Im sure they are going through each and every block off the assembly line to make sure its perfect, goes right back to my comment of them getting magic blocks.
I have seen many cracked blocks I build many many engines. But have yet to see an LS7 crack a sleeve for no reason. Can it happen, sure, Im not saying it hasnt but if you do the research Im sure you'll find unlying problems on most which has led to the cracked sleeve. But I have seen ALOT of problems from blocks that have been resleeved.
Ha,Ha,Ha.....it's all good between me and Bandit other than the fact that he is wrong!! All points aside I do have one thing to add and something I am quite puzzled at. You say Eric K. said that theres no issue with these blocks and to use them without problems? The weird thing about this statement is that I spoke with him many a times on the phone before this last build. I was searching and studying this problem for quite some time. I was really considering Eric to do my 441 for the obvious reasons! Anyhow, he also recommened to me that a sleeved block would definatley be better in the long run for the higher horsepower application that I was trying to achieve. That the LS7 was quite suspect in some instances just because of, like stated above, quick production and shotty tolerances. This is why I had mine done by R.E.D. to be safe and not take a chance. Bandit, I know you have money to burn so I figured this is why it wasn't an issue!? 
Traver
Traver I wish I had money to burn and Eric did tell me if I planned on going bigger than 427 to sleeve it. But its all he said she said, it makes no difference. If I decide to go to a bigger engine I will go for a 454 or bigger and will either use the LSX block or I will see what my options are with a 4.125 bore and 4.50 stroke or something like that would love to do a 480+ small block but we will see.
Typical of people who have no solid evidence to start the name calling. First off I am no "internet warrior". Ill say this straight to you, eric, steve, easter bunny or whoever if asked face to face. An internet warrior is someone thats tuff only behind a screen, which I am not trying to act like, I simply want "proof". So sorry the pursuit of some sort of intelligent insight is seen to you as being an "internet warrior".
Is Steve the only one that knows this??? Maybe, maybe not but throwing it around like its fact is not right either. An yes it has been stated that these are cracking under stock power go back and reread some past posts by Steve and darton.
Then you say Eric is a good friend, ok I think Eric is a great guy an really knows his stuff I value his opinion highly. But when i spoke with him he had no qualms with using the stock LS7 block for me and even has said the same recently to a few that have posted here in this thread. Being they are getting engines built for themselves from Eric using the stock LS7 block right now that kinda goes against you saying he has changed his views.
If you are referring to my comments to Travor (ramair) he is a good friend and he knows I am joking with him. This has been a discussion piece for he and I quite a few times and its the same here. I am not saying anyone is wrong. Have I said the stock block was just as strong as a properly sleeved one???? No quit the opposite. Have I said that the liner in the LS7 is stronger than a darton?? No again the opposite. I have simply implied that coming from someone that is respected in the community (Steve) dont try and start a scare. I have no worries about my block at all, I did at first which is why I started researching this whole situation. The block issue is acually not an issue at all and yeah I can see a few having a problem but as for the majority their fine.
Ow and I love the comment about LPE and Katech getting the cream of the crop. Im sure they are going through each and every block off the assembly line to make sure its perfect, goes right back to my comment of them getting magic blocks.
I have seen many cracked blocks I build many many engines. But have yet to see an LS7 crack a sleeve for no reason. Can it happen, sure, Im not saying it hasnt but if you do the research Im sure you'll find unlying problems on most which has led to the cracked sleeve. But I have seen ALOT of problems from blocks that have been resleeved.
Is Steve the only one that knows this??? Maybe, maybe not but throwing it around like its fact is not right either. An yes it has been stated that these are cracking under stock power go back and reread some past posts by Steve and darton.
Then you say Eric is a good friend, ok I think Eric is a great guy an really knows his stuff I value his opinion highly. But when i spoke with him he had no qualms with using the stock LS7 block for me and even has said the same recently to a few that have posted here in this thread. Being they are getting engines built for themselves from Eric using the stock LS7 block right now that kinda goes against you saying he has changed his views.
If you are referring to my comments to Travor (ramair) he is a good friend and he knows I am joking with him. This has been a discussion piece for he and I quite a few times and its the same here. I am not saying anyone is wrong. Have I said the stock block was just as strong as a properly sleeved one???? No quit the opposite. Have I said that the liner in the LS7 is stronger than a darton?? No again the opposite. I have simply implied that coming from someone that is respected in the community (Steve) dont try and start a scare. I have no worries about my block at all, I did at first which is why I started researching this whole situation. The block issue is acually not an issue at all and yeah I can see a few having a problem but as for the majority their fine.
Ow and I love the comment about LPE and Katech getting the cream of the crop. Im sure they are going through each and every block off the assembly line to make sure its perfect, goes right back to my comment of them getting magic blocks.
I have seen many cracked blocks I build many many engines. But have yet to see an LS7 crack a sleeve for no reason. Can it happen, sure, Im not saying it hasnt but if you do the research Im sure you'll find unlying problems on most which has led to the cracked sleeve. But I have seen ALOT of problems from blocks that have been resleeved.
Second, when I said the LS7 sleeves are weaker, I meant in comparison to the cast-in liner in the other OEM LSx blocks. Stock vs Dartons is a no brainer (given proper installation). The fact of the matter is that the sleeves ARE thinner, they ARE NOT as stable, but they have been successfully run in high horsepower applications and some have not. When the sleeves crack and drop due to detonation and the piston is reasonably intact, it should really clue you in that they aren't as strong as other LS series blocks.
As for the "magic blocks", do you really think that throughout the manufacturing process, throughout the lifespan of the cutters and tooling, that there is no variation in machining precision? I'm not saying Katech has employees hand selecting perfect blocks, but they are probably getting the first batches after new tooling. That is certainly not the case for a lot of shops. Some shops get blocks rejected off the assembly line for whatever reason, but are still OK to run with a little extra work. I have personally seen an LS7 block with provisions for oil squirters and without the scalloped sleeves come straight from GM. Lord knows the discrepancies Steve has seen with all the work he does.
