The engines that we call the "LS" came onto the street back in 1997. They were referred to as the Gen III Small Block. The iron versions were installed in the trucks and the Aluminum blocks were installed in the C5 Corvette. The next year the LS1 were installed in the Camaros and Firebirds. The displacement was slightly different with 346 cubic inches instead of 350.
The Gen III spawned a high performance LS6 in 1999 that became standard in the Z06 Corvette. Then in 2005 the Gen IV came along. This engine had provisions cast into it that allowed for fuel saving ideas such as cylinder de-activation,larger displacements and new cam technology.Some of the performance versions were the LS2,LS3,LS7 and LS9 supercharged. Remember though the the first version of the LS7 came out in 1970-71 and was a 454 cubic inch engine.
The nickname "LS" was actually coined by racers and Hot Rodders,even while GM was continuing to call the engine family the Gen III and Gen IV. It became very apparent that the performance applications of this engine was almost limitless. The iron block engines finding their way into the trucks displaced 4.8L and 5.3L respectively. The all aluminum 6.0L and 6.2L engines were also installed in trucks. The car engines were the 5.3L,5.7L,6.0L,6.2L and 7.0L with some configured for front wheel drive.
Gen III & Gen IV
In spite for the fact the there are differences between the two series of engines,they share some very common things,
4.4" bore centers (the same as thew original small block chevy)
6-bolt,cross bolted main caps
Center main thrust bearing
9.24 inch deck height4-bolt per cylinder head bolt pattern
0.842" lifter bore
Coil near plug ignition system (distributorless)
The biggest difference is cylinder bores on some engines of course and camshaft position sensor locations. They are on the front timing cover of the Gen IV blocks and top rear on the Gen III blocks. The Gen III engines featured 24X reluctor wheels and the Gen IV had the 58X reluctors. There is a high degree of interchangeability between the Gen III and the Gen IV. Cylinder heads,crankshafts,intake manifolds and more can be swapped between them however like it has been for over 50 years with the original small block it may be trial and error. Not every set of heads is going to bolt up to every intake manifold. For more info on it, How To Build High Performance Chevy LS1/LS6 V-8's is one of the best books out there. It gives more specific details on differences and interchangeability.
LS4
One of the most unique applications of the LS4 5.3L engine (323 C.I.D) is in the front wheel drive Impala SS and the Pontiac Grand Prix. The aluminum block with the low profile accessory system includes a flatten water pump design to accommodate the transverse mounting and produces 303 HP and 323 ft/lbs of torque.
LS1/LS6
The 5.7l 364 cubic inch engines were built from 1997 to 2004 (2005 in Australia) for the Camaro,Firebird,Corvette and GTO's. The LS6 came along in 2001 in the ZO6 Corvette and was built through 2005 were it found itself installed in the CTS-V Cadillac. Both the LS1 and LS6 share the same displacement. The LS6 featured an enhanced design for strength and better bay to bay breathing. The heads and intake manifold are also unique to the LS6.
LS2
2005 came along and the 6.0L 364 C.I.D. LS2 was installed in the GM performance cars like the Corvette,GTO and some or the SSR roadsters. And of course with the larger displacement came more power. The LS2 is one of the more adaptable engines of the Gen IV family. The LS1,LS6,LS3 and L92 heads work very well on it. The engine also featured a siamese bore.
LS3/L99
Debuting in the 2008 Corvette with a screaming 430 horsepower the 6.2L was the most powerful engine base ever to come out in the Corvette. The LS3 featured larger stronger siamese bores and Active Fuel Management on the L99 version. Offered in the Pontiac GXP G8 and the new 2010 Camaro. This engine displaces 376 cubic inches.
LSA
The little brother the the LS9,this supercharged 6.2L engine found its way into the CTS-V Cadillac. These engines feature hypereutectic pistons compared the the forged pistons of the LS9 and a smaller 1.9L supercharger with a different cooler design that helps the Caddy smoke the tires with 556 HP.
LS9
This is the most powerful engine Chevy produced. The LS9 is a supercharged 6.2L charge cooled 638 horsepower monster that powers the ZR1 Corvette. This block is strengthened and uses roto cast cylinder heads and a sixth generation 2.3L Roots supercharger and features a dry sump oiling system that mounts outside the engine to help with lubrication under extreme cornering. These engines are also hand built in Wixom,Mich.
LS7
The LS7 is the standard issue engine for the Z06 Corvette. This is the largest displacement small block ever offer in a production car by GM displacing 427 cubic inches. The LS7 uses siamese bored blocks for the 4.125" bores. Competition proven cylinder heads,titanium rods and intake valves help make this a 505 HP street tuned racing engine. These engines are also hand built.
Gen III and Gen IV Vortec Truck Engines
Typically it's been the car engines that have carried the LS designations when it comes to the Gen III and Gen IV engines. The engines installed in the trucks have been dubbed "Vortec" and usually use iron blocks and are smaller displacements then the blocks used in cars. And the 5.7L LS has never been available in the trucks.
Here's the run down,
The 4.8L (293 C.I.D.) is the smallest displacement LS engine,features an iron block, a 3.78" bore and aluminum heads.
The 5.3L (327 C.I.D.) is the most common truck engine using the 3.78" bore and a 3.62" stroke.Later versions of this motor feature "Active Fuel Management". These engines are both aluminum and iron blocks.
The 6.0L (364 C.I.D.) are used in the 3/4 ton and 1 ton trucks. The iron block designation is LY6,aluminum designation is L76. This engine uses aluminum heads and Active Fuel Management.Some are equipt with variable valve timing.
The 6.2L (376 C.I.D) is referred to as the L92. This engine uses an aluminum block and cylinder heads and features variable valve timing. This motor is used in high performance applications like the GMC Yukon Denali and Cadillac Escalade
Part# Description Liters/CID HP Torque
Bore
Stroke
19165628 LS327 5.3/327 327 347 3.78 3.622
17801267 LS1 5.7/346 350 365 3.898 3.622
17801268 LS6 5.7/346 405 395 3.898 3.622
19165484 LS2 6.0/364 400 400 4.0 3.622
17802143 LS364/440 6.0/364 440 404 4.0 3.622
12611022 L99 6.2/376 430 424 4.065 3.622
19244549 LS376/480 6.2/376 485 475 4.065 3.622
19171225 LS376/515 6.2/376 515 469 4.065 3.622
19244097 LS3 6.2/376 430 424 4.065 3.622
19211708 LSA 6.2/376 556 551 4.065
3.622
19201990 LS9 6.2/376 638 604 4.065 3.622
19171821 CT525 6.2/376 525 471 4.065 3.622
19211710 LS7 7.0/427 505 470 4.125 4.00
C5R
The C5R blocks are no production block specially designed and developed for the Corvette racing program. These blocks feature a unique alloy blend of aluminum,and billet steel main caps and are machined with specialized specs. They also undergo a different testing to ensure strength. The siamese bore design allows for a displacement of 427 cubic inches. All LS series heads work of the C5R,however bear in mind that you want maximum air flow.
LSX Bowtie Block
2007 braught with it the new LSX block,it's a durable and affordable cast iron version designed to support very high performance applications and even has provisions for 6 bolt head fastening. 3.88 bores that get finished to 3.89" or even as large as the max 4.2". You have to keep in mind that the rotating assembly for a stroke larger than 4.125". Deck height on the LSX blocks are 0.020 taller than the production ls blocks. However the standard LS cylinder heads work with the LSX blocks.
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