Pitbull11

I know about the supercharger. What I am looking for is what are the structural changes GM made to the standard 6.2 liter, other then the supercharger to make it this beast? I'm talkin all the modifications GM had to do to make the ZR1 engine stay together for the long term.

4evervette

forged steel crank..forged pistons.. forged titanium connecting rods....forged steel main bearing caps ....thats what i remember now

3LZZ06

Also piston oil squirters to keep things cool and lubed...

Ohh...it's 640 but who's counting...:-)

911/Q45

Does the base engine have cross bolted mains? Dry sump oiling too. I'm thinking the whole engine is a different animal.

3LZZ06

I think only the manual GS coupe has the dry sump, not sure about the mains.

MachAll 2005

I believe the LS9 also has a unique block casting (material and method)...also has larger head bolts and a more robust head gasket design. Head casting material, valves, More flywheel to crank bolts, oil pump may be higher capacity due to the piston spray jets, etc. Likely other changes beyond what was mentioned above.
Here is the "big picture"

SDPC

All LS engines have cross bolted mains

Pilot03EBZO6

Block is the same casting its just machined differently.. Difference include the squirters, head bolt threads of course, and also the depth of the crank sensor (to help rigidity).. The heads are cast a different way to make them stronger and ports smoother. Roto cast is the name for the process.

GOLD72

I had thought I had read that the block casting pattern was modified to give it more strength in critical areas from the standard LS3 block.

Pitbull11

The block #'s are the same so I doubt any difference. The head #'s are different so we know they are not the same. Anyone have a source that goes into detail on the internals of both engines???

newschool

Umm,I was under the impression the block and heads both were cast from a better material.

Pitbull11

Logic would dictate that if they were different in anyway they would have different numbers, otherwise how would anyone know they were different?

newschool

Well i know the webbing is different on the ls9.Also the head studs are 12mm.The LS9 has billet mains and oils squirters.I just called SDPC and the guy said they aren't the same casting.The have different part #'s.

Pitbull11

not what the current corvette black book shows

barry1me

The Cast block could be the same, but the machining may be different on the LS3 and LS9.

newschool

They are not the same. Here are the casting #'s for the c6 blocks.

12564243
LS2 (6.0L/364ci)
2005-2007

12600821
LS3 (6.2L/376ci)
2008-Present

12578452
LS7 (7.0L/427ci)
2006-Present

12621771
LS9 (6.2L/376ci)
2009-Present

Pitbull11

Hate to tell you but these are the Head numbers, which are different.

Per the Corvette Black Book written by Mike Antonick -
2009 thur 2012- Block#: 12621766 376ci, 430hp and 638hp

MachAll 2005

I have a .pdf document from GM titled "2010 LS9 Description" that describes the distinctions. IF someone can tell me how to post this document, I will.....or it is likely avail via a web link that I can't locate at this time?
Also, see a neat animation at http://www.youtube.com/watch?v=mIKNccRDvRo
Dick

z51vett

The blocks are the same but will carry dif part #'s because of the machining. If the ls9 has special machining but they could be the same they just block of piston squirters. Bare blocks now not short blocks. When the ls3 came out they talked about the dif between it and the ls2 engines and how it was beefed up. This makes me think they are same but machined diff.
z51vett

z51vett

Hey this is the same book that was used on me at charlotte N.C. back in 78 or 79 telling me I had an illegal carb on my Corvette 1978 Bought it new I worked for GM and know it was not. I had ordered car and it was never touched.
z51vett