Ls1 / ls2 / ls3/ ls6 / ls7 ????

[Samckitt]

Ok back when the LS1 first came out I knew the differences between it & the classic small block Chevy engines. Now that it has been out for a few years there are many many versions of the "new" motor. Is there a location on the net I can go to & read about the differences between all these versions & what is interchangeable between them?

Thanks

[Shawn MacAnanny]

http://ls1tech.com/forums/forumdisplay.php?f=5

best website for LS1 engines.

LS1 and LS6 are 346 cu in. The LS1 uses 806, 853, and 241 heads (241s being the newest 67cc chamber). These came in 97-04 vettes and 98-02 f-bodys and some year gtos

The LS6 uses 243 heads (flowing the best of the LS1/LS6 heads) they came in 01-04 covertte z06s

LS2s are 6.0Ls all aluminum. They came with i believe 799s, and 243s (66cc chamber) as well. They came in GTOs in the later years and C6 corvettes

There are also several other engines available for the LS2 setup which are the LQ4 (And iron 6.0L with 317 heads which are 243s with a 72cc combustion chamber) and dish pistons bringing the lq4 to a 9:5:1 CR. These comes in most 3/4 ton trucks

There is the LQ9 which came in silverado ss's which is the same as an lq4 but with flat top pistons and about 10:1 CR

While on the subject of trucks there is also a 5.3L ls1 available, the LM7 which has its own heads which are i think 862s. These are iron 5.3Ls. There is also an aluminum 5.3L version available in suburbans and tahoes i believe.

There is also a 4.8L which will look identical to the 5.3L, same heads, but the only different is the actual stroke i believe.

The LS3 is a 6.2L engine. It comes in caddilac escalades It will have L92 heads. These are close to the same as LS7 heads. They are rectangular port and flow somewhere in the 320cfm stock i believe. They are also 12 degree heads.

The LS7 is of course the 427 06+ Z06 motor. It uses the L92 style heads. It doesnt like boost too much because of the thin cylinder walls. This is why they are using the LS9.

The LS9 is a version of the 6.2L lS3. I dont know much about it. It comes in the 08 Corvette Zr1s

There is also an LS4. It's an all aluminum 5.3L that uses the 243 cylinder heads. It comes in the 05+ Impala SS and Monte Carlo SS plus the Pontiac Gran prix gtp. It's a front wheel drive cast block so its bolt pattern is made to mate to the 60* builk pattern of most moder 6 cylinders. The only problem is that it has no starter provison on the block. The start must be mounted in the transmission.

Oh and around 2005 or 2006 they switched over from the 2x cam sensor and 24x relutor wheel (crank sensor) to the 4x cam sensor and 58 reluctor wheel. MSD makes boxes to fit both setups to runt hem carbureted (like mine). 6010 for the 24x, 6012 for the 58x. Edelbrock makes a performer rpm intake and victor JR intake for the carbureted LS1 headed applications. GMMP makes a Victor JR style single plane for the LS1 heads AND the L92 style heads. These carburetor single plane manifolds are also available with injector bungs so they can be run fuel injected. I've seen some incredible gains with a 4150 style on the single plain intake.

Heres one example

http://www.ls1tech.com/forums/dynamometer-results-comparisons/1031160-408-w-vic-jr-dyno-s-after-t-b-change.html

I'm sure there are a few innaccuracies in there but that is the jist on LSx engines.

[John McIntire]

damn Shawn! Thanks for the crash course!

[Samckitt]

Agree, thanks Shawn, lots of info there, will take a while to sink in.

Are all the heads interchangeable between all of them? What about intakes? I have heard/read that the tall truck ones work best.

[Shawn MacAnanny]

Also you can stick the heads from a smaller bore engine on a larger bore but not a larger bore head on a smaller bore engine. I.E. 5.3L heads can go on 5.7 or 6.0 and i think you can use the 6.0L heads on the 5.7L but i know you cant use the L92 heads on a 5.7L because their intake valves will hit the cylinder wall. They need atleast a 4.00 bore.

Also those with the 4x cam sensor use different camshafts i believe. At some point they change the cam gear over to a 1 bolt setup instead of a 3 bolt setup. I dont know the year or what motors though.

If you need any help with a carb setup, i have all kinds of pictures, tuning information and part numbers for ya for that.

[Samckitt]

If I was to go with an LSx style motor, I would keep fuel injection on it.

[Shawn MacAnanny]

Yeah most do. I highly reccomend the Victor JR EFI intake with a 4150 TB though. Thats pretty much the highest flowing setup IMO. Just for those who dont know the MSD carbureted boxes run off of your cam and crank sensor and allow use of a map sensor to control and advance engine timing. They also plug into you stock coil packs to fire the coils.

https://static1.pt-content.com/images/noimg.gif

[WS6]

The LS3 is a Corvette motor. The L92 is the truck motor. Same basic motor though. The cylinder heads are the same and are known as L92s regardless. The L92 heads use LS7 intake ports but LS6 exhaust ports. Any porting of L92s should concentrate heavily on the exhaust as it can not handle what the intake can bring in.

The LS7 head has D port exhaust.

Also keep in mind we have two different generations of engines here. LS1/6 along with LQ4/9 and the 4.8/5.3 truck motors from 99+ til 05? are Gen 3. The LS2/3/7/9, and L92 are Gen 4 motors. This matter in terms of the reluctor wheels and cams. The Gen4 motors have the cam sensor on the front of the cam. Gen 3 rear. You can swap around Gen 3 cams in Gen 3 engines only. People do put pull out LS6 cams into 5.3s as an example.

Heads swap around regardless of generation so long as the valves will fit the cylinder bores like Shawn already mentioned. The L92/LS3 and LS7 heads use offset intake rockers because the valves were so big they had to move the center line over. The cam lobe spacing did not change just the offset rockers.

All Gen4 motors use a 4 bolt motor throttle body. Gen 3 was 3 bolt and either motor or cable throttle body depending on application or with the trucks, build date.

The easiest way to approach the LSx engines I believe is to simply decide what do you want and what can you afford. From there you can narrow your info done. I say this becuase the technology surrounding these engines is moving very fast. The early LSx engines are being left behind. As great as an LS1 is, it'll be the 307s of the group in a couple more years. Costs of the new stuff is what keeps it viable now. LS1 heads are worthless now basically but in 97 through the early 2000s they were amazing. It's just changing technology and advancements.

Are you looking to change your LT out for an LSx now Scot?

[Samckitt]

Right now I am not looking to change it out. I am just about to the point that the LT1/Monte is running again. Maybe someday as the LSx makes more power than traditional small blocks do. I keep toying with the idea of making a Trailblazer SS clone. Even though others have said I would probably be better off just buying a true SS.