ZR1 cam specs and LSA
 

Has anyone figured out what the LSA is on the LS9? I found the duration and lift but no one seems to know the LSA? Also does GM sell it? Thanks

Is GM keeping this a secret or does no one know?

211/230 @ .050, seems to be the 427 LS7 cam but using 1.7 ratio rockers instead of 1.8
I can tell u GM did leave a little on the table as far as power goes, and the parts they would need are already in GM inventory:yesnod:
And who's idea was that rev-limit?:D

I found the LSA it is 122.5

I thought the LSA on the LS7 cam was 120??? Does this mean the LS9 cam isn't the same as the LS7 cam? Lift numbers I found for the LS9 were .562"/.558" so that seems pretty consistent with the difference between a 1.7 and 1.8 ratio rocker.

Cheers, Paul.

No way the LS7 cam is even close to the LS9, the LS9's cam is designed for the blower, you are comparing a high compression NA car vs a Low compression FI car, not even close.

Okay, the same lift (notwithstanding rocker ratio), duration on both intake and exhaust are exactly the same, and the LSA is right around 120 on both...so, I'm curious, what exactly is "not even close" :eek:

Do you know exactly what it is about the LS9 cam that makes is SOOOO different from the LS7 cam (notwithstanding that the specs are almost identical) or are you just assuming the cams are very different because one is NA and the other FI?

Cheers, Paul.

I beg to differ.....the ls7 and ls9 cams are VERY close, if not exact same. They may have widened the LS but the lift difference is from the 1.7 rockers. Does not matter to me, mine will be out of the car soon, along w/ the heads and some other useless items. 1200mi now, by 2k mi, 9sec pass:thumbs:

In GM's system, the lobe lift (measured on the cam) on both LS7 and LS9 is .331" on the intake and .328" on the exhaust. The duration is also the same, but it does not specify the LSA. I am pretty sure since the rest of the measurements are identical, so s the LSA. As others have stated, the only difference is the 1.7 vs 1.8 rockers. :thumbs:

Wow!! I just assumed, being that they are entirely different motors, they dont sound the same at Idle, the sweet spots in the two cars feel very different, I know that is from the FI, I guess I thought GM would have designed a more specific cam for the car.

I'm with you. I've already replaced my cam and heads. :thumbs:

http://forums.corvetteforum.com/c6-c...-part-1-a.html

says lsa is 122.5 degrees and that the cam is not identical to the ls7

did I miss your post?! Details, please!

Then they widened the lobe separation to retain boost, it's done all the time w/ blower cams. Remember that any overlap is going to bled off cyl. pressure (and boost) at lower rpms.

agreed, same lobes just spread them apart...what does the zr1 idle at exactly?

:lurk: :bigears

Here scroll down the page: http://corvetteactioncenter.com/spec..._pursuit6.html

LS9 Cam
 

The LS9 cam has a 122.5 LSA. Actually the lobe profile between the LS7 and LS9 is SIMILAR but the LS9 cam is a different animal altogether because, as noted above, it's designed for the S/C and Heat. A great article on the LS9 engine is in HOT ROD Mag July 2009. Check it out.:thumbs: