LS3/L92 vs. LS2 block
08-04-2009, 08:20 AM
#1
LS3/L92 vs. LS2 block Is there a great deal of difference in strength when comparing these two engine blocks? I called Scoggin Dickey to order an L92 block and he said to get the LS2 block because the LS2 was a stronger piece. Has anyone heard such a thing? I am currently using an 6.0L block in my '68 Camaro but would like to save the 100lbs off the nose of the car if I could. It is an N/A street car and has a best of 10.34 @ 130.18.
08-05-2009, 03:09 AM
#2
TECH Resident
Is there a great deal of difference in strength when comparing these two engine blocks? I called Scoggin Dickey to order an L92 block and he said to get the LS2 block because the LS2 was a stronger piece. Has anyone heard such a thing? I am currently using an 6.0L block in my '68 Camaro but would like to save the 100lbs off the nose of the car if I could. It is an N/A street car and has a best of 10.34 @ 130.18.
GM interview quote:
"There are improvements in the LS3 block. Compared to last year's six-liter, the liners have .084-in larger bores, its main
bearing webs are about 20% stronger and their "windows", which enhance "bay-to-bay breathing" in the interest of oil
control and reduced parasitic loss, have been somewhat enlarged."
Read it and more at:
http://corvetteactioncenter.com/spec...ls3_page1.html
L92/LS3 blocks have the same PN now.
08-05-2009, 04:38 PM
#4
TECH Resident
Based on GM's position that the blocks are more durable/stiffer than the earlier (6L/LS2), and the slightly larger bores mean less valve shrouding with L92/LS3 style heads, they do have an advantage. So its all about the $$.
Plus do you want to tell your buddies that you have an LS2 or an LS3?
08-05-2009, 04:54 PM
#5
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we have built many 416 ls3 engine,n/a boosted,n2o all great engines.The ls3 block is a very strong block but then again so is the ls2,i haven't found the upper limits of either yet and we've done a couple 1000+rwhp ls3's and many ls2's reaching up into the 1700hp range.
08-05-2009, 05:13 PM
#6
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we have built many 416 ls3 engine,n/a boosted,n2o all great engines.The ls3 block is a very strong block but then again so is the ls2,i haven't found the upper limits of either yet and we've done a couple 1000+rwhp ls3's and many ls2's reaching up into the 1700hp range.
08-05-2009, 05:49 PM
#7
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I asked the engine builder that I am working with about a LS3 block for my next project Monday when I was there they had said they would be concerned with cylinder wall distortion at the 700 horsepower level but they would build it if I absolutely wanted to.
When your stock blocks such as the LS3 and LS2 blocks come back how do the cylinders look, do they move around, compared to a LSX or Warhawk which should be better in many ways.
Why wouldn't we all just use stock stuff instead of the upgrade?
When your stock blocks such as the LS3 and LS2 blocks come back how do the cylinders look, do they move around, compared to a LSX or Warhawk which should be better in many ways.
Why wouldn't we all just use stock stuff instead of the upgrade?
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08-06-2009, 10:31 AM
#8
Most builders I have spoken to say you will typically lose 20-30hp because of lost ring seal due to cylinder wall distortion and expansion of the aluminum surrounding the liners. These guys are building super late model engines with brodix blocks and such. I suppose the factory cylinder liners of an aluminum block will never be as strong as an iron block. But everything is a compromise. I am wonder if anyone on here has done a comparison between "similar" builds?
08-06-2009, 04:22 PM
#9
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Most builders I have spoken to say you will typically lose 20-30hp because of lost ring seal due to cylinder wall distortion and expansion of the aluminum surrounding the liners. These guys are building super late model engines with brodix blocks and such. I suppose the factory cylinder liners of an aluminum block will never be as strong as an iron block. But everything is a compromise. I am wonder if anyone on here has done a comparison between "similar" builds?
To me 20 or 30HP lost is made up by the 100lbs or so missing off the front end compared to an iron block. Going from a BBC to an AL LS7 in my 68 Camaro saw the weight of the car drop by 250lbs. Front end is much better behaved in the turns.
What turns? 
08-09-2009, 04:22 PM
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08-09-2009, 06:34 PM
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we have built many 416 ls3 engine,n/a boosted,n2o all great engines.The ls3 block is a very strong block but then again so is the ls2,i haven't found the upper limits of either yet and we've done a couple 1000+rwhp ls3's and many ls2's reaching up into the 1700hp range.
You using the ls3 in these 1000 rwhp jobs with the ls3 heads or aftermarket?
08-09-2009, 07:17 PM
#16
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08-10-2009, 10:10 AM
#19
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to answer a few questions,
an iron block will always we better-we did a test on a 650hp bbc,one with an iron block and one with an aluminum block-everything else was identical.the iron block motor made more power-about 15hp and had less blowby.
if you can afford the weight the iron block is better as far as hp-the down sides are weight,not easy to repair,not easy to modify.
we have converted several ls2/3 blocks to six bolt-they are very strong,will easily handle 2000hp
i don't use stock casting heads on anything over 800hp
an iron block will always we better-we did a test on a 650hp bbc,one with an iron block and one with an aluminum block-everything else was identical.the iron block motor made more power-about 15hp and had less blowby.
if you can afford the weight the iron block is better as far as hp-the down sides are weight,not easy to repair,not easy to modify.
we have converted several ls2/3 blocks to six bolt-they are very strong,will easily handle 2000hp
i don't use stock casting heads on anything over 800hp
08-10-2009, 12:37 PM
#20
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to answer a few questions,
an iron block will always we better-we did a test on a 650hp bbc,one with an iron block and one with an aluminum block-everything else was identical.the iron block motor made more power-about 15hp and had less blowby.
if you can afford the weight the iron block is better as far as hp-the down sides are weight,not easy to repair,not easy to modify.
we have converted several ls2/3 blocks to six bolt-they are very strong,will easily handle 2000hp
i don't use stock casting heads on anything over 800hp
an iron block will always we better-we did a test on a 650hp bbc,one with an iron block and one with an aluminum block-everything else was identical.the iron block motor made more power-about 15hp and had less blowby.
if you can afford the weight the iron block is better as far as hp-the down sides are weight,not easy to repair,not easy to modify.
we have converted several ls2/3 blocks to six bolt-they are very strong,will easily handle 2000hp
i don't use stock casting heads on anything over 800hp
i am new to GM performance. i came over from the "dark side" and it seems that they all go from iron to aluminum and all the GM guys goes from aluminum to iron. seems weird to me.
you stated that the iron block made 15 hp more but doen't that get eaten up and then some with the added weight if you use the rule of "every 7 lbs takes 1 hp". atleast thats what i've always been told.