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Subject:Re: Cam timing
From:John Rodgers
Date:Mon, 20 Aug 2007 10:06:54 -0500

No valves in a two stroke engine. And I remember correctly, the plug
fires on every crank rotation, unlike a four stroke.

John Rodgers
88 GL Driver

Pensioner wrote:
> Lift and Duration are the two parameters of interest in cam design along
> with the ramp geometry.
>
> Lift is how far the cam pushes the valve open.  Measured in inches.
>
> Duration is how long the cam keeps the valve open.  Measured in degrees.
>
> Overlap is the degree (Degrees/360) of total rotation where both the intake
> and the exhaust valves are open at the same time.
>
> The ramp geometry determines the acceleration of the valve and valve train
> as it is pushed up by the cam lobe.  This attribute helps to determine the
> rpm at which valve 'float' occurs.  When the valve cannot follow the
> oscillation of the cam lobe it is said to 'float'
>
> Why don't 2 stroke engines have valve float? (NVC).
>
> Al (some cats are two stroke)
>
>
>