As far as I know its just the names that GM gave their HiPo motors thru the years.

and you hear this every where "Yeah man its got a LT1 in it" Everyones got a LT1 it seems like......and .....mmm i didnt think that they made THAT many lol, and and why dont I have one?

 

Wikipedia has a good amount of reading on this. Here are the old small blocks:

Small blocks pre LT1

The LT1

And finally the LS series


Enjoy!

K

 

Thanks for asking..I am not up on all this new fangled stuff myself...

Sam

 

Good links from Killer. The LS1 made its debut in 1997 in the Corvette, 98 in the Camaro/Firebird, and the pickup version (the Vortec 4800, 5300 and 6000) came out in 99 in the Silverado pickups. LS2 I believe is the 6.0L Gen IV rated at 400hp found in the Corvette (and the Cadillac CTS-V?). The LS6 was the hopped of version of the LS1 5.7L found in the C5 Z06 Corvettes. And the LS7 in th 7.0L 505hp engine in the current Z06 Corvette.

 

Good info and links. I'll add a quick synopsis. The classic small block (sometimes referred to as gen1 or SB1) is the old style. Starting in 91-92 the LT1/L99 emerged. It has a lot in common with the older SB1, but many parts don't directly interchange. For the most part, the rotating assemblies will interchange. It uses the same style one-piece rear main crank, rods, and pistons with minor differences. The cam is different because the front of the cam drives a front-mount distributor and water pump, but things like journal sizes and bore spacing are the same as the old SBC. If you pulled the pan off an SB1 and an SB2, you'd have to look very close to see any internal differences. Heads are different and won't interchange at all. The water passages are different to take advantage of the SB2's reverse cooling flow. The LS1 is the third generation and is a clean slate design. Whole different critter.

Within each family there are variations in head, intake, and other minor changes. For instance LT1 and LT4 share interchangeable shortblocks, but the heads and intake on the LT4 have higher ports. Converting an LT1 to an LT4 means basically a head and intake swap. The LT5 was in the mix for a while, but it was an exotic one-off built by Lotus and has nothing to do with the other LTx family.

The LS1 is a similar story. The 1, 4, and 6 are much like the LT engines; head and intake are the main differences. The LS2 and 7 are still very similar, but they are an evolution of the first LS family. The LS3 is yet another evolution.

 

Good info and links. I'll add a quick synopsis. The classic small block (sometimes referred to as gen1 or SB1) is the old style. Starting in 91-92 the LT1/L99 emerged. It has a lot in common with the older SB1, but many parts don't directly interchange. For the most part, the rotating assemblies will interchange. It uses the same style one-piece rear main crank, rods, and pistons with minor differences. The cam is different because the front of the cam drives a front-mount distributor and water pump, but things like journal sizes and bore spacing are the same as the old SBC. If you pulled the pan off an SB1 and an SB2, you'd have to look very close to see any internal differences. Heads are different and won't interchange at all. The water passages are different to take advantage of the SB2's reverse cooling flow. The LS1 is the third generation and is a clean slate design. Whole different critter.

Within each family there are variations in head, intake, and other minor changes. For instance LT1 and LT4 share interchangeable shortblocks, but the heads and intake on the LT4 have higher ports. Converting an LT1 to an LT4 means basically a head and intake swap. The LT5 was in the mix for a while, but it was an exotic one-off built by Lotus and has nothing to do with the other LTx family.

The LS1 is a similar story. The 1, 4, and 6 are much like the LT engines; head and intake are the main differences. The LS2 and 7 are still very similar, but they are an evolution of the first LS family. The LS3 is yet another evolution.

W0W ! all this new fangled stuff you wrote about made my head spin. I kinda knew about the LT1 and reverse cooling.


Thanks for explaining / helping ......


Mustangsaly

 

Thanks for the links and explanations. I've been avoiding threads with anything in them referring to these motors because I just haven't learned about them. When someone would mention LT1, my mind automatically shifted to the 1970 vintage 350 'Vette motor.

 

Yes, frustrating. The 70s 350 that bears the same RPO code is typically referred to as the LT-1 while the new one is listed without the hyphen.


All of these engine names we're talking about are RPO codes, but on the street we use them to refer to the family of engines. For instance, the LT1 style engine also came as a 4.3 V8 in many caprices and was given the RPO code of L99. Often times its just referred to as the "baby LT1" since its externally identical

 

Yes, frustrating. The 70s 350 that bears the same RPO code is typically referred to as the LT-1 while the new one is listed without the hyphen...........l

yeah that stuff can be confusing.
Shane

 

Good info and links. I'll add a quick synopsis. The classic small block (sometimes referred to as gen1 or SB1) is the old style. Starting in 91-92 the LT1/L99 emerged. It has a lot in common with the older SB1, but many parts don't directly interchange. For the most part, the rotating assemblies will interchange. It uses the same style one-piece rear main crank, rods, and pistons with minor differences. The cam is different because the front of the cam drives a front-mount distributor and water pump, but things like journal sizes and bore spacing are the same as the old SBC. If you pulled the pan off an SB1 and an SB2, you'd have to look very close to see any internal differences. Heads are different and won't interchange at all. The water passages are different to take advantage of the SB2's reverse cooling flow. The LS1 is the third generation and is a clean slate design. Whole different critter.

Within each family there are variations in head, intake, and other minor changes. For instance LT1 and LT4 share interchangeable shortblocks, but the heads and intake on the LT4 have higher ports. Converting an LT1 to an LT4 means basically a head and intake swap. The LT5 was in the mix for a while, but it was an exotic one-off built by Lotus and has nothing to do with the other LTx family.

The LS1 is a similar story. The 1, 4, and 6 are much like the LT engines; head and intake are the main differences. The LS2 and 7 are still very similar, but they are an evolution of the first LS family. The LS3 is yet another evolution.

Actually the LT1 didn't debut until 1993. 91-92 vettes and f-bodies still had TPI.

 

Lt1 came out in the 1992 year model Corvette.

 

All the LSX motors have 6 bolt mains and are all aluminum. The LS1 is a 5.7 liter, but doesn't share bore and stroke with the gen 1 SBC. You can get carb manifolds for the LSX family of motors. Lots of info out there and in this thread.

 

All the LSX motors have 6 bolt mains and are all aluminum.

Not all of them are all aluminum. The Vortec truck engines that came out in the 99-up Silverados are part of that same family of engines (the Gen IIIs). They have cast iron blocks. Around 2001 or so they started to appear with aluminum heads...

 

Not all of them are all aluminum. The Vortec truck engines that came out in the 99-up Silverados are part of that same family of engines (the Gen IIIs). They have cast iron blocks. Around 2001 or so they started to appear with aluminum heads...

Spaced that off completely, was only thinking of the Vettes and camaro. Sorry for the bad info.