High-Lift Camshaft Timing
Referencing the How to Rebuild and Modify Porsche 911 Engines book. Can someone educate me on:
1. Why there is a separate set of cam timing instructions for High-lift, High-Duration Camshaft Timing?
- Reduced-lift instructions: rotate till your dial indicator reads desired value. Remove pin. Turn crank to Z1.
- High-lift instructions: rotate crank to Z1. Remove pin. Turn cam to desired value.
Won't these both deliver the same result, regardless of reduced-lift or high-lift ?
2. Why "you need to keep the dial indicator pegged on the desired value while you are tightening it (camshaft nut) down"?
- If the pin is installed in the sprocket, it seems to me the position of the sprocket to the cam, and therefore the camshaft relative to the crank, is effectively fixed.
Thank you.
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