prowan

I have a Z06 CAM (PN 12565308) and got through degreeing the cam in my engine build. I have measured the following values:

Intake Valve Open (0.050") = 19.5 Deg After Top Dead Center
Intake Valve Close (0.050") = 43.5 Deg After Bottom Dead Center

Peak valve Lift Occurs at 121.5 Deg After Top Dead Center

According to what I have found on the internet, the Lobe Separation Angle is 117.5 deg. If that is the case, then the CAM has been ground with a 4 Degree Retard. Is that correct?? With a 117.5 deg LSA and being installed 'Straight Up' would yeild a 0.050" Opening = 15.5 Deg ATDC. Is the CAM designed to be installed 'Straight Up' or have -4 Deg Retard?? I have an adjustable timing chain set that I can adjust if necessary. I sure would appreciate anyone's help!!

Hugger67RSSS

iTrader: (2)

I'm not a master of this stuff but thought that GM installed almost all of their cams "straight up" remember reading an article about it on here.

prowan

Just checking if anyone else could chime in on this issue?? Thanks in advance!!

joecar

The 5308 specs are DUR 204/218, LSA 117.5, ADV -2.5, which gives LCA 120/115

i.e. it is retarded 2.5° (supposedly), and you have it retarded an extra 1.5° so there's your 4°.

Here is a pic I drew to "see" the specs (attached).

prowan

Thanks for your reply and drawing!! If you don't mind, where did you find the cam specs showing the 2.5 deg retard?? That is what has frustrated me so is the only published data I could find was the durations And LSA.. I really appreciate the help!!

3rdCoastPowerSports

iTrader: (5)

install the cam strait up then degree it to find the ICL
What is your ICL? That will tell you weather the cam has a built in advance or retard.

joecar

See MY02 LS6 here: http://www.corvetteactioncenter.com/...ls3_page6.html