Camshafts phase timings
I have installed stage 1 camshafts with specifications of 10.5mm lift and 270 degrees duration for the intake. 10mm lift and 270 degress duration for the exhaust.
The stock specifications is 9.5mm lift with 235 degrees duration for both.
Not that satified with the camshaft's manufacturer settings, I have decided to phase the intake camshafts to open earlier by 2 degrees or about 1/2 a cam sprocket tooth at TDC.
This has met with rattling above 2000 rpm. So I went on to open at 1 degree earlier. No rattling but idle was slightly off. But the pick up from mid range (3000 rpm) is really fast.
My question is on Alfa's cam variator. Does the variator advance the intake camshafts briefly or permanently above 2000 rpm? Is this advance 6 degrees or 1 sprocket tooth?
Anybody out there changed to high compression piston? 11.5:1 CR? What are your results? Can you share them?
96' 155 16V TS 2.0L