Whizzer Cam Timing
On the late model Whizzers the cam installation as delivered from the factory provides an intake closing that is so late the engine doesn't have any dynamic compression. I believe moving the cam one crankshaft tooth moves the cam timing 14-15 degrees. So think about it, if advancing the cam 1 tooth provides 75 deg ABDC IN closing, it had ~ 90 deg ABDC closing as delivered from the factory. This is way to late an IN closing for anything good to ever happen, and for sure kills any chance of having a decent dynamic compression ratio. The 75 deg closing provides very reasonable cam timing. One of you curious sorts that's going to make such a change should measure the cranking compression before and after advancing the cam and let us know how much it increases (perhaps someone already has posted that but I can't recall) .
On the late model Whizzers the cam installation as delivered from the factory provides an intake closing that is so late the engine doesn't have any dynamic compression. I believe moving the cam one crankshaft tooth moves the cam timing 14-15 degrees. So think about it, if advancing the cam 1 tooth provides 75 deg ABDC IN closing, it had ~ 90 deg ABDC closing as delivered from the factory. This is way to late an IN closing for anything good to ever happen, and for sure kills any chance of having a decent dynamic compression ratio. The 75 deg closing provides very reasonable cam timing. One of you curious sorts that's going to make such a change should measure the cranking compression before and after advancing the cam and let us know how much it increases (perhaps someone already has posted that but I can't recall) .
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