thanks for the info mate! csn you give me any info on that selection? or why not possibley the third one?
cheers!
Sure first thing is Cam2 has -10° overlap vs Cam3 -14°, so while both higher than stock, Cam2 has more apparent “caminess”, a positive in this study.
These mild cams share near identical exhaust close and intake opening, both offer a bigger gulp earlier than any GM’s cams which means more intake charge at more usable RPM bandwidth.
However the defining difference is the intake close event (by far weighs the most important), and also differs with the exhaust opening.
Cam2 IVC is 65.5° ABDC - Very Early
Cam3 IVC is 71° ABDC - Early
Search the web for EIVC vs LIVC for more detail but main thing is higher effective compression bump to 8.3:1 vs stock 7.9:1, you will notice that translates to more torque in the lower range, easier low idle, possibly better fuel economy depending on tune. Good power up to safe RPM too, fastest NA zetas use EIVC cams, google “little Lunati”.
By far the biggest mistake people make with cams is specifiying a huge duration intake which extends IVC and lowers compression and torque down low, doesn’t perform until dangerous peak RPM (useless).
On the other hand Cam3 IVC is 71°, still EIVC and hugely better than for the Commie than the LS3’s Corvette-spec cam.
The second main difference is the exhaust open event, Cam3 EVO is relatively early which will produce higher average power and a flat torque curve across the power band.
I've noticed with an early IVC event and an early EVO event our car is much faster at the track and produces much more torque from the early close.
Combine a late EVO event with added overlap (which Cam3 doesn't have) and the right IVC event and you have a torque monster of a cam that will pull to whatever you limit it to with the IVC event.
So Cam2 gets my vote.
My cam Matrix worksheet:
