Need some GM engine education - Lateral-g Forums

67Sally · #1 10-04-2005, 10:47 PM

Can someone tell me the basic difference from Gen I, Gen II, Gen III, and Gen IV.

W.

MarkM66 · #2 10-05-2005, 08:33 AM

I'll start it. Not sure how much you're wanting to know though.

Gen I was the first small block chevy. Cubic inch started at 265, and went to 400 though the years.

Gen II was the LT1 and LT4. No rear distributor. Not sure on all the cubic inch sizes. Not to be confused with the Gen I LT-1.

Gen III. Started as the LS1. And I'll stop there, not real knowlegable off hand.

Gen IV. ?

67Sally · #3 10-05-2005, 08:46 PM

Thanks for the start Mark. The basics is all I am looking for right now.

And the questions continue..........
Is the the new ZO6 engine an LS-7? is it considered a Gen IV? Is there such a thing as a Gen IV?

W.

Musclerodz · #4 10-05-2005, 11:13 PM

There is actually two versions of what you are calling Gen I. There is a 2 piece rear main seal block and a 1 piece rear main seal. In '88 they also went to roller camshaft setup.

Mike

sinned · #5 10-05-2005, 11:37 PM

The new Z06 is an LS7 and is a gen IV as is the LS2.

MarkM66 · #6 10-06-2005, 10:57 AM

Quote:

Originally Posted by Musclerodz

There is actually two versions of what you are calling Gen I. There is a 2 piece rear main seal block and a 1 piece rear main seal. In '88 they also went to roller camshaft setup.

Mike

Yep. I'm running a later model block in my Nova. If you want a roller, and a T56 it's the way to go.

67Sally · #7 10-06-2005, 08:51 PM

Thanks for the infor guys. Some more basics please.

What makes the LS7 and LS2 different from the other the other LS engines.

I am assuming that there are LS1's, LS3's, LS4's, LS5's, LS6's.....are there? and is this what people are talking about when they say LSx?

Thanks,
W.

Musclerodz · #8 10-06-2005, 10:23 PM

LS2 is very similiar to LS1, the LS7 is kind of a breed of its own. LSx refers to any of the LS based engines including truck engines starting from 99 and up with the 5.3 and 6.0 engines.

Mike

Musclerodz · #9 10-06-2005, 10:25 PM

Oh and I forgot to mention that when talking LSx motors, it does not refer to the older LS5, LS6, and LS7 big block motors, only the new ones.

Mike

sinned · #10 10-06-2005, 10:40 PM

Actually "all" of the other LS engines are not LS engines, they just get that nomenclature as it easily understood as genIII engines. The only LS engines are the 5.7 LS1, the 5.7 LS2, and the Z06 LS7. "All" the other genIII engines (the 4.8, 5.3, iron 5.7, and the 6.0) are just genIII engines.

The LS2 is very similar to the LS1, some head modifications and oiling issues resolved but the LS7 is a truly unique piece of automotive genius, do a google on Z06/LS7.
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