I asked this question in LS1LT1.Com boads but I havnt gotten an answer. I know that there a lot of Kknowlageable people here at thirdgen.org!!! Any ways the cam (after market cams) that I have and the cam for the LS1 are similar to mine but the operating range for the LS1 covers a broader rpm band. Here take a look:

My Cam (XR276HR) Comp Cams
Operating range: 1800 – 5800
Advertised Duration: 276 in / 281 ex
Duration @ .05: 224 in / 230 ex
Lift with 1.5: .503 in / .510 ex (I’m not sure exactly what life it would be with 1:6 rockers)
LSA: 112

LS1 Cam (XR269HR) Comp Cams
Operating range: 1300 - 6300
Advertised Duration: 269 in / 273 ex
Duration @ .05: 216 in / 220 ex
Lift with 1.7 rockers: .525 in / .532 ex
LSA: 114

One More LS1 cam(XR273HR) Comp Cam
Operating range: 1600-6600
Advertised Duration: 273 in / 277 ex
Duration @ .05: 220 in / 224 ex
Lift w/ 1:7 rockers: .530 in / .534 ex
LSA: 112


My question to you guys is why is the operating range so much greater?? I would love to put one of those cams or get a custom grind cam with the LS1 grind to get that performance range!!! But I don’t think I would see the same results. But can anyone of you guys tell me why it is so much different. I was thinking that the LS1 was based off the 350 block. Are the heads at the same angle, 23*, as the traditional Chevy blocks? I really can’t think of any other differences between the two 350 motors. Well if you guys know just let me know.

 

The LS-1 is a totally different animal than a Gen 1 SBC. Stock the heads are great and they're incredible when properly ported. The base circle of the camshaft is larger, increasing valvetrain stability with higher lifts and high ratio rocker arms. So the valvetrain design is part of the reason for the difference, but not the only reason.

 

Thats really interesting!! Now I wish I had an LS1!!!! Thanks for you input.

 

LS1 cam has the same journal size as a BBC. Thats about as close as you can compare anything in it to a SBC. LS1 is basically a fresh new design, nothing in common at all with older engines.


Found an article I stashed away back in 98 when I bought my SS. Can't remember where I found it or who to give credit to but it is a more indepth answer to your question. Can't post it cause it's almost 60,000 char's and the limit is 15,000. If you want it I'll send it to your email.

 

I believe the heads on the LS1 are 18 degrees versus the 23 degrees on the SBC for better flow. Like was stated above the LS1 basic design is much better than the SBC and so the flow will be greater resulting in a greater rpm range for a given cam.

 

The operating range listed is just to give the consumer some general information. The intake manifold has a great deal to do with operating range and peak power. A TPI vs. a MiniRam with the same cam. The TPI will still peak in the upper 4000 rpm range while the MiniRam will peak above 6000 rpm.

I see in your sig that you'll soon be installing a MiniRam on your 383. When I dynoed my 383 MR with the Comp XE 230/236, the motor made peak HP at 6450 rpm. You will love the broad powerband the MiniRam gives.

www.geocities.com/dzperf

 

HalfInchWrench I would love to get that artical about the ls1 it would be really interesting to read!! My eamil adress is spedrace35@gmail.com. Well thanks for helping me out with my little question you guys it has helped a lot.

I was hoping that my rage would go up more with the mini ram I just cant wait to get my motor running and to get it on a dyno!! I want to ask you a question about your old motor (383), I see that your cam was a little larger then mine and I am wondering if your car is a daily driver. I am asking becasue I am wondering if you had trouble passing emissions. It is one thing that I am worried about with my car. I did just look at your web site and that is one nice car you got there!! And a nice big motor to add to that!

Well thanks for the feed back you guys!!

 

spedrace35 - I have successfully passed emissions tests in Illinois and Ohio. The 383 passed in Ill. with the 230/236 hyd. roller cam while my 406 passed in Ohio sporting a 242/242 solid roller.

I am using DFI gen 6 for engine management and I strongly believe that is why I was able to pass. You should not have a problem with the 224/230 cam.

Good luck!

 

thanks a million!!

 

Just sent the article. Think it was from some kind of vette magazine that had the article online at the time it was published.

 

Hey thanks a million, its a long artical!! I started reading it, its very interesting. Thanks again for the artical!