L-92 vs LS7 block strength
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On The Tree
Joined: Dec 2005
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From: Cooper City, FL
L-92 vs LS7 block strength Besides the actual cubic inch advantage, is the LS7 block that much stronger? If so, where and why? Do any advantages of the LS7 block when being used in a wet sump application justify the extra price of the LS7 block?
We're planning a nice strong 418-427ci setup for a C5 and the plan is to have an extremely stout, reliable bottom end that will see some heavy nitrous and possibly boost in the future. We want to make sure to do all of our homework before spending money on parts.
I know the L-92s haven't had much of a chance to prove themselves, but any input is appreciated here.
We're planning a nice strong 418-427ci setup for a C5 and the plan is to have an extremely stout, reliable bottom end that will see some heavy nitrous and possibly boost in the future. We want to make sure to do all of our homework before spending money on parts.
I know the L-92s haven't had much of a chance to prove themselves, but any input is appreciated here.
I'd go L92 if budget is anything of a concern. The LS7 is weak compared to a resleeved LS2 (which costs about the same). Or, you could go for the new GMPP iron block coming soon. It will be strongest of all and only a bit more expensive than the LS7 if you are needing something to support an F2 Procharger or something.
Since the LS7 has fairly weak iron liners and less material between the cylinders (while using the same aluminum block as the LS2), I'd think a regular LS2 would be stronger than the LS7 even if the liners were the same strength. If the L92 is as strong as the LS2 (but I don't know - I think I've read it's a different casting, but who knows if it's actually stronger), then we have our answer.
Since the LS7 has fairly weak iron liners and less material between the cylinders (while using the same aluminum block as the LS2), I'd think a regular LS2 would be stronger than the LS7 even if the liners were the same strength. If the L92 is as strong as the LS2 (but I don't know - I think I've read it's a different casting, but who knows if it's actually stronger), then we have our answer.
Last edited by JakeFusion; Dec 7, 2006 at 10:48 PM.
Originally Posted by JakeFusion™
Since the LS7 has fairly weak iron liners and less material between the cylinders (while using the same aluminum block as the LS2)
Originally Posted by Bill Reid
... using the same block? Weak liners? Really? Please elaborate...
I don't know how accurate this information is, but that's what I remembered when I posted last night. I just went and found this post, however.
Also, Steve from RED says this:
https://ls1tech.com/forums/showpost....02&postcount=5
He knows more than I, even if he wants to sell a Darton liner. I believe for most people the LS7 will work (or the L92), but for extremely high boost, one might look to a Darton MID or C5R or GMPP or Warhawk block.
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The LS7 has steel main caps and push in type sleeves. It would be stronger than the L92 which is still a very nice block. Depending on your power level waiting for the GMPP iron block may be better.
Kurt
Kurt
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TECH Enthusiast
Joined: Jul 2006
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From: sofla
Originally Posted by 427
The LS7 has steel main caps and push in type sleeves. It would be stronger than the L92 which is still a very nice block. Depending on your power level waiting for the GMPP iron block may be better.
Kurt
Kurt
Thanks for the info Kurt.
On The Tree
Joined: May 2003
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From: Kennesaw, Ga
My GM High Performance Parts catalog's at home... so I'm going by recall.
I think GM shows the max. recommended horsepower for various blocks including the LS7. As I recall... the LS7 block had the highest HP. rating of the LS blocks, excluding the C-5R/C-6R blocks.
Maybe someone has the catalog at hand.
I think GM shows the max. recommended horsepower for various blocks including the LS7. As I recall... the LS7 block had the highest HP. rating of the LS blocks, excluding the C-5R/C-6R blocks.
Maybe someone has the catalog at hand.
Originally Posted by JakeFusion™
https://ls1tech.com/forums/showpost....76&postcount=1
I don't know how accurate this information is, but that's what I remembered when I posted last night. I just went and found this post, however.
Also, Steve from RED says this:
https://ls1tech.com/forums/showpost....02&postcount=5
He knows more than I, even if he wants to sell a Darton liner. I believe for most people the LS7 will work (or the L92), but for extremely high boost, one might look to a Darton MID or C5R or GMPP or Warhawk block.
I don't know how accurate this information is, but that's what I remembered when I posted last night. I just went and found this post, however.
Also, Steve from RED says this:
https://ls1tech.com/forums/showpost....02&postcount=5
He knows more than I, even if he wants to sell a Darton liner. I believe for most people the LS7 will work (or the L92), but for extremely high boost, one might look to a Darton MID or C5R or GMPP or Warhawk block.
Aftermarket sleeving with superior quality sleeves will no doubt strenghthen and already strong block. No argument there
And the other blocks you mention are most definitely solid foundations to building ultimate horsepower. But for the recently mentioned expected horsepower and LS7 or a sleeved LS2, to obtain up the 427 requirement here, would be more than plenty.Bill
Staging Lane
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From: under the hood
Bill,
You are right on! The LS7 block was designed after the LS2, and designed for a higher hp level from the get-go.
I don't think anyone can argue that the Darton sleeves are stronger when compared to the stock LS7 sleeves. Material selection and bore wall thickness provide that answer.
However, there is no way that you can prove that removing the entire original cylinder bore material (material that connects the main bearing bulkheads to the deck face) and then pressing in a sleeve, a sleeve that for the most part is "floating" in space (I know, it's really compressed between the head and the machined land at the bottom of the bore once the engine is assembled) is stronger in terms of being able to withstand more load than the original block.
FEA would prove that resleeveing an LS2 block for 4.125 bore sleeve is weaker than the LS7 that is designed for the 4.125 sleeve and is weaker than the original LS2 block.
You are right on! The LS7 block was designed after the LS2, and designed for a higher hp level from the get-go.
I don't think anyone can argue that the Darton sleeves are stronger when compared to the stock LS7 sleeves. Material selection and bore wall thickness provide that answer.
However, there is no way that you can prove that removing the entire original cylinder bore material (material that connects the main bearing bulkheads to the deck face) and then pressing in a sleeve, a sleeve that for the most part is "floating" in space (I know, it's really compressed between the head and the machined land at the bottom of the bore once the engine is assembled) is stronger in terms of being able to withstand more load than the original block.
FEA would prove that resleeveing an LS2 block for 4.125 bore sleeve is weaker than the LS7 that is designed for the 4.125 sleeve and is weaker than the original LS2 block.
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From: sofla
Is what I'm reading here telling me that it basically boils down to which bore size I'd prefer, as both blocks are fully capable of supporting the expected power levels here? What if we decided we needed an extra 100 horses in the future, is 750 at the wheels out of the question with the L92?
Really hoping this does not turn into a 'they're all the same block' pissing match gentlemen.
Thanks for all the responses so far...keep em coming!
Really hoping this does not turn into a 'they're all the same block' pissing match gentlemen.
Thanks for all the responses so far...keep em coming!
Originally Posted by LSX Wizard
Bill,
You are right on! The LS7 block was designed after the LS2, and designed for a higher hp level from the get-go.
I don't think anyone can argue that the Darton sleeves are stronger when compared to the stock LS7 sleeves. Material selection and bore wall thickness provide that answer.
However, there is no way that you can prove that removing the entire original cylinder bore material (material that connects the main bearing bulkheads to the deck face) and then pressing in a sleeve, a sleeve that for the most part is "floating" in space (I know, it's really compressed between the head and the machined land at the bottom of the bore once the engine is assembled) is stronger in terms of being able to withstand more load than the original block.
FEA would prove that resleeveing an LS2 block for 4.125 bore sleeve is weaker than the LS7 that is designed for the 4.125 sleeve and is weaker than the original LS2 block.
You are right on! The LS7 block was designed after the LS2, and designed for a higher hp level from the get-go.
I don't think anyone can argue that the Darton sleeves are stronger when compared to the stock LS7 sleeves. Material selection and bore wall thickness provide that answer.
However, there is no way that you can prove that removing the entire original cylinder bore material (material that connects the main bearing bulkheads to the deck face) and then pressing in a sleeve, a sleeve that for the most part is "floating" in space (I know, it's really compressed between the head and the machined land at the bottom of the bore once the engine is assembled) is stronger in terms of being able to withstand more load than the original block.
FEA would prove that resleeveing an LS2 block for 4.125 bore sleeve is weaker than the LS7 that is designed for the 4.125 sleeve and is weaker than the original LS2 block.
Its all good
Bill
Originally Posted by Bill Reid
Doing your own independant research, instead of reading and regurgitating internet hype, will confirm that. Once you find out for yourself accurate information then maybe you'll reconsider your statement the LS7 block is weak.
Originally Posted by 11 Bravo
I could be mistaken, but I didn't see him say the LS7 block is weak unless it was in a different reply. The sleeves seem to be. And the person who showed they are is the best in the business with probably more experience working with cylinder blocks than everyone on this site combined.
. I will say that there is ALOT of block building experience floating around this forum on top of who you are referring to ... and tapping ALL that knowledge along with doing some foot work yourself would be great research.Bill
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From: sofla
The cost of re-sleeving any of these blocks would put this out of the 'budget' theme of the build. My question is concerning the as cast/sleeved strenth of these block as they are available from GM. I would surely consider the L92 block over the LS2 simply for the added bore size, and the LS7 would be the choice if it is truly that much stronger.
Staging Lane
Joined: Aug 2006
Posts: 91
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From: under the hood
Bill,
I think there some misunderstanding...... I wasn't picking on you, and you never said the LS7 was weak. I was actually looking at the beginning part of your post where you said that the LS2 and LS7 are very different blocks and where you challenged JakeFusion who said it was weak.
What I continuously read in this forum is how weak the LS7 block is (
) compared to a resleeved LS2. I have yet to deal with LS7's that have broken sleeves. I must be lucky I guess. Maybe I'm missing something somewhere, or maybe I'm reading into something. I know that Jason from Katech has made it quite clear that their testing does not support a lot of the claims made here.
I agree with you that each individual has to make a conscious decision as to the parts they are willing to live with at the end of the day. I would personally never use a LS2 with the large bore sleeves for reasons stated in my earlier post. I personally would use (prior to release of the GMPP LSX and the World Warhawk) the C5R for large bore high hp applications. With the new parts that are now (soon to be) here, I'm no longer locked into that deal.
gun5l1ng3r,
FEA is Finite Element Analysis..... a way of computing the stresses and deflections of a component
I think there some misunderstanding...... I wasn't picking on you, and you never said the LS7 was weak. I was actually looking at the beginning part of your post where you said that the LS2 and LS7 are very different blocks and where you challenged JakeFusion who said it was weak.
What I continuously read in this forum is how weak the LS7 block is (
) compared to a resleeved LS2. I have yet to deal with LS7's that have broken sleeves. I must be lucky I guess. Maybe I'm missing something somewhere, or maybe I'm reading into something. I know that Jason from Katech has made it quite clear that their testing does not support a lot of the claims made here.I agree with you that each individual has to make a conscious decision as to the parts they are willing to live with at the end of the day. I would personally never use a LS2 with the large bore sleeves for reasons stated in my earlier post. I personally would use (prior to release of the GMPP LSX and the World Warhawk) the C5R for large bore high hp applications. With the new parts that are now (soon to be) here, I'm no longer locked into that deal.
gun5l1ng3r,
FEA is Finite Element Analysis..... a way of computing the stresses and deflections of a component