GM Engines

[Nima]

Well, I know this may get very complicated but I always get confused about different names and types of GM engines for cars and light trucks specially when we combine that name with their displacement . I know we have small and big block engine but dosa that the same as short and long block? what year did they start fuel injection and computer? (that helps somebody like me when I think about donor vehicle) What are the different names means LS1, LS2 etc? If somebody could put them in order or refer a site that has this info, I would be greatly appreciate.
Thanks.

[byrd]

short block means just block with internals, no heads.
Long block would be the block with internals and the heads as well.
I have no idea on the Ls motors.

[Longhorn Man]

actually, a short block is a complete lower engine, crank, rods, pistons, cam, and everything to assemble it.
A long block, includes all that jazz, and complete heads too.

[EAST SIDE LOW LIFE]

The L'ssssssss are engine designation codes, let me give you a few examples ....

* LT1 370 hp (with A.I.R, system) 1970

* LS5 390 hp 454 engine - 1970

* LT1 330 hp (with A.I.R, system) 1971

* LS5 365 hp 454 engine - 1971

* LS6 425 hp 454 (with A.I.R, system) 1971

* LT1 255 hp (with A.I.R, system) 1972

* LS5 270 hp 454 (with A.I.R, system) 1972

SOURCE: N.C.R.S. Spec. Guide. These are Corvette specifications and will vary with orher Chevy and GMC models. For exact hp and other information please referr to literature pertaining to your specific vehicle.

************************************************

This will give you a bit of an idea as to how these codes work. The engine codes may repeat themselves but depending on the year that is being referred to the hp and pollution equipment changes.

esll.

[Nima]

Well, I thought something along this:
small blocks: 305,327,350, 383, (any more?)Are these engines are 5.0 or 5.7?
Big block: 400, 454 (any more?)How many liter are these?
LS1:
LS2:
LT1:
Etc:

[brak]

somewhere in the late 70's or early 80's engine manufacturers switched over to the metric system when referring to engine size, thereby listing Litres instead of Cubic Inch. Since Liters are not exactly equal to Cubic Inches, they round the number to the nearest Liter.

5.0L = Chevy 305 or ford 302
5.7L = Chevy 350

The small block remained relatively unchanged from the late 1950's up to 1987 and most people refer to those engines as "GEN I". "GEN II" showed up in 88 when the heads were changed to the centerbolt style, but the engine has very few other differences from the Gen I engines.

LT and LS, as well as LQ have been used throughout the years to distinguish different production engines, but when people talk about LT1 LS1 LS2 etc, they are referring to the newer models from the late 80's to the present.

The LTI was built on the Gen II platform and used in camaro's firebirds and Corvettes starting in the late 80's. When the LS series appeared in the early 90's it ushered in a new Block that was radically different than the previous 2 generations. The new naming convention takes into account changes that have been made to the design, so the number after LS designates the series.

As far as fuel injection, corvettes began running a mechanical fuel injection system back in the 50's, but it wasn't until the early to mid 80's (1985 for most gm vehicles)that computer controlled fuel injection started popping up.

[RACINJASON22]

This artical In Chevy high performance I think will answer alot of your questions. The Best Things Come In Small Packages -History of- Chevy High Preformance Magazine

Should shed some light on the subject. Good Read IMO. RJ22

[72armyswbtruck]

Small Block 400
Big Block 400 (also in trucks was the 402, or 396 with 400 badges)
Small Block 383 (chevy 350 with a 400 crank)
Big Block 348

[Sicmaro]

LS1 = 97-04 corvette 98-02 camaro/firebird 04 gto.
LS6 = 00-04 corvette Z06
LS2 = 05-06 corvette 05-06 gto 05-06 SS trailblazer
LS7 = 05-06 corvette Z06

the truck motors have diff "names" but.......

5.3l = late 99 - current truck 01 - current tahoe/yukon
6.0l = late 99 - current truck 01 - current tahoe/yukon/escalade/denali


LS1 = 5.7l Alluminum block
LS6 = 5.7l Alluminum block
LS2 = 6.0l Alluminum block
LS7 = 7.0l Alluminum block

hope this helps some.......... btw first post!!! haha

[71Chevy4-speed]

Originally Posted by Nima

Well, I thought something along this:
small blocks: 305,327,350, 383, (any more?)Are these engines are 5.0 or 5.7?
Big block: 400, 454 (any more?)How many liter are these?
LS1:
LS2:
LT1:
Etc:

Smallblocks GEN I - 265, 283, 302, 305, 327, 350, 400(factory)

Smallblock GEN I combos - 334(stroker 305 lol) 358, 377, 383, 412, 427, 434, 454 etc (options are just about limitless.)

Bigblocks - 366, 396, 402, 427, 454 (factory, about like smallblocks all kinds off combos ex. 434, 496)
LS6 454 ('70 SS Chevelle) not to be confused with the LS6(newstyle smallblock.)

LT1 GEN II - 5.7 Liter. Loses the distributor in back and moves it to the front of the engine behind the water pump, Centerbolt style valve covers. Coventional style head "vortec"

LT4 GEN II - 5.7 Liter, as far as I know same style intake and heads on this but better numbers, guys any info?

GEN III (did away with 5th head bolt around cylinder due to it being in the way of a highflowing port)

LS1 GEN III - 5.7 Liter. Loses the distributor completely, goes to coil on plug, redesigned the heads to have long narrow ports(looking at intake side, hence why they flow so good)

LS6 GEN III - guys fill in some info here?, haven't read much on these.

LS2 GEN IV - 6.0 liter same basic design as LS1 more cubes.

LS7 GEN IV - 7.0 liter Same basic design as LS1 and LS2 but 427 cubes (some things are different such as crank signal on LS7 has more pick up points than LS2... something to keep in mind if swapping an LS7 in an LS2 car and wanting to use the factory harness.)

L92 GEN IV - 6.2 liter - variable valve timing I've read??

Vortec truck engines - 4.8L, 5.3L, 6.0L, 8.1L

Personally I like carb motors so I like GEN I, but for injection motors forget LT1 style, LS series is much much better.

[tavenner13]

this site is great, too. i found it last night. tells how to calculate displacement, compression height, cc's, and has a huge chart of casting #'s and bore x stroke for all early GM engines. neat stuff

http://www.musclemotorparts.com/intheknow.htm