So whats the strongest aluminum block?
On The Tree
Joined: May 2014
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Is there actually a durability issue with the alumn blocks? I understand that re-sleeving the actual LS motors isn't really feasible and that isn't really THAT big of an issue, atleast not as far as i'm concerned. You're really only going to need to do that if you have some catastrophic failure. I don't really consider that a durability issue.
I also understand the cyl walls are thinner on actual LS motors but at what point does that actually become an issue? Wouldn't you have to be running crazy boost or compression for that to actually be an issue?
Am I missing something?
I also understand the cyl walls are thinner on actual LS motors but at what point does that actually become an issue? Wouldn't you have to be running crazy boost or compression for that to actually be an issue?
Am I missing something?
Restricted User
Joined: Mar 2014
Posts: 7,192
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From: Ohio
Is there actually a durability issue with the alumn blocks? I understand that re-sleeving the actual LS motors isn't really feasible and that isn't really THAT big of an issue, atleast not as far as i'm concerned. You're really only going to need to do that if you have some catastrophic failure. I don't really consider that a durability issue.
I also understand the cyl walls are thinner on actual LS motors but at what point does that actually become an issue? Wouldn't you have to be running crazy boost or compression for that to actually be an issue?
Am I missing something?
I also understand the cyl walls are thinner on actual LS motors but at what point does that actually become an issue? Wouldn't you have to be running crazy boost or compression for that to actually be an issue?
Am I missing something?
I hear that there were lots of improvements to strength of the main webbing over the LS2 blocks once the LS3 blocks rolled out. I'm not sure if those changes took place in the newer 5.3 blocks or not.
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Verdad Gallardo On The Tree
Joined: May 2014
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So I did not know about the additional webbing/support but again, when does torsional rigidity of the block actually become an issue? Obviously we all want the best and the strongest parts that are available but I can't see this being something that has any impact on 95% of the vehicles on this forum. I could see a block possibly flexing or cracking in a full blown max effort race car making like 1500+hp but I just can't wrap my head around it being an issue for anything less than that. And at that power level your probably not even considering using a stock block.
I would love to be enlightened if this actually is an issue and something to be concerned about.
I would love to be enlightened if this actually is an issue and something to be concerned about.
Even if there is not enough distortion for catastrophic failure, any block, crank, valvetrain distortion causes HP loss. This was evn more of an issue when SBC's started getting close to the quad didgit HP numbers.
Thread Starter
TECH Fanatic
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From: roanoke virginia
In todays world 1000HP boosted LS motor is not as uncommon as it once was so why not use the best block available. I think that even the stroke has a pretty good effect on how much "flex" a block will have.
Thats why i asked because I know there are allot smart guys with allot of experience on here.
Personally seen 2 LS2 blocks flex and take out mains around 1000whp. So I would say yea the extra webbing is defiantly a plus. However all this is for nothing with only 4 bolts per cylinder. Much more than 1000whp and it's basically a wash.
On The Tree
Joined: May 2014
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Well I learned something today 
I've never heard of block flex being an issue and never imagined it could be something to actually worry about. Good lesson!
There are indeed many smart people on this forum who know much more than I ever will. Thats one of the biggest reasons I subscribe to this particular forum.
My comment about not using a stock block at the 1500hp-ish mark was in reference to the 4 bolt mains.
I've never heard of block flex being an issue and never imagined it could be something to actually worry about. Good lesson!There are indeed many smart people on this forum who know much more than I ever will. Thats one of the biggest reasons I subscribe to this particular forum.
My comment about not using a stock block at the 1500hp-ish mark was in reference to the 4 bolt mains.
Teching In
Joined: Sep 2015
Posts: 21
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Don't forget about pinning the main caps either. That will help a lot with the caps walking. Fireball ran 7s at close to 200 with an LS2 block with pinned mains. A newer 5.3L aluminium block with pinned mains would probably be the strongest.
I have read a few things about the LSA/9 block being somewhat stronger than your run of the mill L92/LS3 block, but I'm not sure how much truth there is to it.
I have read a few things about the LSA/9 block being somewhat stronger than your run of the mill L92/LS3 block, but I'm not sure how much truth there is to it.
FormerVendor
Joined: Aug 2014
Posts: 473
Likes: 1
Alot of differences in an LS9 block and an LS3 block...
LS9 has oil squirters, LS3 does not
LS9 has 12mm head fasteners LS3 has 11
LS9 has steel main caps, LS3 does not.
Theres more but thats 3 off the top of my head.
LS9 is the strongest stock aluminum block.... followed by a later 5.3 block/LS3/LS2.
Teching In
Joined: Sep 2015
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Meh, like you said, that's an opinion. The caps will start moving around the 4 digit mark, 1000hp is not the magic number where you start lifting heads, there are more than a handful of people making over 1000hp on a 4 bolt block. Pinning the mains is a minimal cost compared to an LSX block.