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So I installed the 120/104 cam on the left bank.
The cam specs are
IVO (BTDC) = 32 degrees
IVC (ABDC) = 52
EVO(BBDC) = 44
EVC(ATDC) = 24
Lobe centre = 100
Intake lift @ 0.050 = 0.476
Exhaust lift@ 0.05 = 0.450
Webcam calls for a timing setting of 5.2mm intake with .1mm lash at overlap.
When I measure the intake its 5.2mm at overlap but the exhaust is around 3.2mm looks like the cam is really 4 degrees advanced (I have a degree wheel on the crank pulley and a dial guage on both intake and exhaust valves). I also noticed that the lift is
Intake lift = 0.464" vs 0.476
Exhaust lift = 0.430" vs 0.450
So are they really telling me that I should install it with 4 degrees advance? Or do I have a rocker arm ratio problem or cam base circle reduced such that it doesn't give me the full specified lift and then I have an offset when setting timing at overlap?
When I do a Dyno2000 plot with 4 degrees advance it brings the torque lower with very little affect to the top end.
Perhaps I will go with this setting.
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