LS3 versus LS7 Engine Longevity
Thread Starter
Racer
Joined: Jul 2004
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From: New York NY
LS3 versus LS7 Engine Longevity
I have seen passing references to better engine longevity for the LS3 vs the LS7. Is this fact or fiction and if so the reasons why. Also, what type of mileage can one expect from a well maintained LS3 vs LS7?
Thanks,
Ken
Thanks,
Ken
Safety Car
Joined: Jun 2006
Posts: 4,007
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From: Ashland, OH
the LS3 im sure.....the LS1,2,6 will have longer longevity than either one of those as well, for example the 1,2,3,6 all have the almost ideantical blocks the 1,6 have 3.9 bore, the 2 has 4.0 bore, and the 3 with a 4.060 bore. The 1,2,6 will have lighter pistons less stress and more 'meat' between the cylinder walls.
Race Director
Joined: Oct 2004
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The big difference is that the truck derived LS3 has press in cylinder liners while the LS7 has cast in place liners. That means the LS3 block can be rebuilt, the LS7 must be discarded.
Drifting
Joined: Apr 2007
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From: Central Florida
How can one know which will last longer when both of them are fairly new? One can make an educated guess, but no one really knows. I think this should be decided in the years to come when people start to put real miles on both engines. IMO, I think it's too early to tell.
Le Mans Master
Joined: Nov 2005
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A nonrebuildable block....is this a first for Corvette?
Team Owner
Joined: Aug 2003
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But then again, how many cars have you owned which had to have the engine block rebuilt?
Last edited by '06 Quicksilver Z06; Dec 14, 2007 at 12:33 AM.
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Team Owner
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From: Raleigh / Rolesville NC
Dont abuse the engine and change the oil and these engines are almost indestructible.
Melting Slicks
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Race Director
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No, I didn't mean to say that at all. I meant to say what I said. The LS1, LS6, LS2, and LS3 all use pressed in cast iron cylinder liners. All of these can be removed and replaced when they wear out. The LS7 has so little room between bores that the factory actually casts the liners in place rather than machining the raw blocks and pressing in separate liners the way they do for the other engines. Thus the LS7 block is a throwaway when it wears. Chevy has only ever made one other engine with a throwaway block, the infamous Chevy Vega engine.
Melting Slicks
Joined: May 2007
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No, I didn't mean to say that at all. I meant to say what I said. The LS1, LS6, LS2, and LS3 all use pressed in cast iron cylinder liners. All of these can be removed and replaced when they wear out. The LS7 has so little room between bores that the factory actually casts the liners in place rather than machining the raw blocks and pressing in separate liners the way they do for the other engines. Thus the LS7 block is a throwaway when it wears. Chevy has only ever made one other engine with a throwaway block, the infamous Chevy Vega engine.
Last edited by PAmotorman; Dec 14, 2007 at 11:01 PM.
Team Owner
Joined: Jul 2001
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From: Various places in Southern California.
Was that intentional though? I though Reynolds sold them on an aluminum alloy that would have the durability of a cast iron block. As I recall, the Vega motors didn't use liners at all (at least not the first couple years of production).
Melting Slicks
Joined: May 2007
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the cylinder wall finish on the reynolds 390 alloy block was very very critical and in production GM never quite got it right and they used oil.a lot were sleeved with cast iron for the repair
Drifting
Joined: Feb 2007
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From: Southlake Texas
No, I didn't mean to say that at all. I meant to say what I said. The LS1, LS6, LS2, and LS3 all use pressed in cast iron cylinder liners. All of these can be removed and replaced when they wear out. The LS7 has so little room between bores that the factory actually casts the liners in place rather than machining the raw blocks and pressing in separate liners the way they do for the other engines. Thus the LS7 block is a throwaway when it wears. Chevy has only ever made one other engine with a throwaway block, the infamous Chevy Vega engine.
tomhenryracing.com
"The LS7 has its roots in motorsports--the four-time, 24-Hours-of-LeMans winning C5.R and C6.R Corvettes, to be exact. Its aluminum block is derived from the C5R Racing Block (PN 12480030, also available at THR) used by those road racing Vettes. LS7 is, also, related to the Generation 3 and 4 Small-Block V8 engine families used in the Corvette, Camaro and Chevy full-sized trucks, however, it differs from those production engines in certain areas.
First, it has pressed-in cylinder liners, rather than the cast-in-place liners of other Gen 3/4s. Those pressed-in liners have 104.8-mm bores rather than the 101.6-mm or smaller, bores of others. Its cylinder heads, also, have racing pedigree through a reduced, 12° valve angle rather than the 15° of other Gen 3/4 engines. The valve angle reduction improves airflow through the heads' intake ports. The intake manifold is, also, a unique part developed through the Corvette Racing program. LS7 has a dry-sump oiling system inspired by the dry-sumps used in racing and developed for the Z06's high lateral acceleration ability."
Melting Slicks
Joined: May 2007
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tomhenryracing.com
"The LS7 has its roots in motorsports--the four-time, 24-Hours-of-LeMans winning C5.R and C6.R Corvettes, to be exact. Its aluminum block is derived from the C5R Racing Block (PN 12480030, also available at THR) used by those road racing Vettes. LS7 is, also, related to the Generation 3 and 4 Small-Block V8 engine families used in the Corvette, Camaro and Chevy full-sized trucks, however, it differs from those production engines in certain areas.
First, it has pressed-in cylinder liners, rather than the cast-in-place liners of other Gen 3/4s. Those pressed-in liners have 104.8-mm bores rather than the 101.6-mm or smaller, bores of others. Its cylinder heads, also, have racing pedigree through a reduced, 12° valve angle rather than the 15° of other Gen 3/4 engines. The valve angle reduction improves airflow through the heads' intake ports. The intake manifold is, also, a unique part developed through the Corvette Racing program. LS7 has a dry-sump oiling system inspired by the dry-sumps used in racing and developed for the Z06's high lateral acceleration ability."
"The LS7 has its roots in motorsports--the four-time, 24-Hours-of-LeMans winning C5.R and C6.R Corvettes, to be exact. Its aluminum block is derived from the C5R Racing Block (PN 12480030, also available at THR) used by those road racing Vettes. LS7 is, also, related to the Generation 3 and 4 Small-Block V8 engine families used in the Corvette, Camaro and Chevy full-sized trucks, however, it differs from those production engines in certain areas.
First, it has pressed-in cylinder liners, rather than the cast-in-place liners of other Gen 3/4s. Those pressed-in liners have 104.8-mm bores rather than the 101.6-mm or smaller, bores of others. Its cylinder heads, also, have racing pedigree through a reduced, 12° valve angle rather than the 15° of other Gen 3/4 engines. The valve angle reduction improves airflow through the heads' intake ports. The intake manifold is, also, a unique part developed through the Corvette Racing program. LS7 has a dry-sump oiling system inspired by the dry-sumps used in racing and developed for the Z06's high lateral acceleration ability."
Drifting
Joined: Feb 2007
Posts: 1,537
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From: Southlake Texas
the LS-7 has pressed in sleeves so the block can be serviced if a cylinder need repaired since the cylinder sleeve is too thin to be bored oversize. the other LS blocks have thicker cast in cylinder sleeves and can be bored oversize if needed for repair. to make big bore blocks from the non LS-7 blocks you bore out the cast in sleeves and install pressed in sleeves
The statement(s) that "the LS1, LS6, LS2, and LS3 all use pressed in cast iron cylinder liners while the LS7 has cast in place liners" is(are) not correct.