-what's different about these new motors conpaird to the ls1?
-what potential do these motors have?
-will ls1 / ls6 heads and intake bolt up to these motors?

 

In general they are very similar with the exception of the iron block. The 6.0 has a decent head with the exhaust port approaching that of the LS6, but with a larger combustion chamber..... great starting point for a low compression LS1 blower motor. Interchangeability is very good with the exception of rotating assembly components. I don't have all the specific bore/stroke combinations to post, but GM did a pretty good job of keeping parts interchangable.
Lonnie Pavtis
Lonnies Performance Automotive]

 

As said before... THey are very interchangeable. The LS6 heads are far superior to any of the other ones.

 

The 4.8L, 5.3L, 5.7L (LS1/6) and 6.0L all interchange.

Iron Block vs. Aluminum Block

The heads on the truck engines are interesting. The LS6 heads are the best but the most expensive, the 6.0L heads are in second place as far as porting goes. I have seen some very good results from the 6.0L heads. Besides you can mill the chambers down to where you need them, and on a big inch engine they are helpfull to get them where you need them in terms of chamber cc's.

The 5.3L heads are about the same as the LS1. Some people like the 5.3L chambers better, and I have seen some good exahaust port numbers from them. The LS1 heads probably are a better intake though.

The 6.0L has a 4.0" bore, while the 5.7L have a 3.898 bore with the same stroke. The 5.3L bore esacpes me but it has the same stroke as the other two. The 4.8L has the same bore as the 5.3L but a shorter stroke. (BTW a 4.8L crank with a 5.7L bore is a 312 cube engine)

The only things that are the same on these engines compared to the old gm SBC is........

1. Rod journals are 2.1"
2. Bore spacing is 4.400"

That's about it.

The potential is pretty good. LS1 heads are a easy 300cfm. Guys are getting some monster cubes from them now, not that they heads can support them as well as a big block head can for the same displacement. 427 I feel is the biggest you should go but there is a 480cube LS1 engine being built now. With C5R heads, which are VERY GOOD! 400+cfm good. The heads on these engines is the best series of heads GM has ever cast for street cars.

I am building a 383 LS1 now that I expect over 500rwhp from NA, not something you see out of LT1's all the time. (not with hyd rollers and a nice idle)

anyways, they are more expensive but make alot of power.

Check out LS1tech.com

Bret

 

Definetly very difficult.. you need supercharging for that.. but in the end.. what is the difference.. supercharged or not... its what performs...

 

thanks

 

Did you guys see the TA in the GMHP mag a few monther ago? They put a set of lightly ported GM 4.8 litre truck heads on the LS1 with a fair size hydralic cam and it made well over 400 RWHP. Any of you LS1 guys try that setup?

 

I think they were 5.3l used...

anyways.. ls6 heads are superior...

 

The 5.3L and 4.8L heads are the same anyways.

400rwhp out of a 224/224 cam with TEA CNC 5.3L heads is easy with the addtional bolt ons.

The LS6 heads are not needed unless you have over 400cubes on a Gen III engine, then they need to be ported corectly. I have seen some so-so numbers come out of LS6 heads from some of the big names. I have seen 6.0L heads flow 340cfm so if you are going to use LS6 heads you need them for serious flow 350+

Bret

 

Alot of guys are running the 5.3L head setup with different cams...224's, 226's, and reverse-split duration 230's. 410-440 hp depending on selection and additional bolt-ons.

 

the 4.8-5.3l heads are very good way to go they have a smaller combustion chamber which will bump your compresion up a bit i have seen good results with them after they have been ported