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Old 12-Oct-2006, 13:25
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andyb andyb is offline
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"getting them synchronised so they open and close together"

well this bit..........

In the first instance, you need to ensure valve clearances are within tolerance and as there is a range with tolerance, you want it i would suggest to the lower end of the scale, as once the follower is riding on the opening or closing slope of the cam the less time its taking to close up a clearance gap the more pedantic it can be about at which point it opens or shuts the valve.

Once that is done it is a question of where you want a particular cam, be it for the inlet or exhaust, horizontal or vertical cylinder, in relation to that particular cylinders piston to crank position, generally spoken as degrees before or after TDC, top dead centre.

Moving the cam position can be achieved with either vernier pulleys, pulleys that have a seperate centre to outside parts so their relevent positions to each other can be adjusted, or the use of an offset woodruff key, the semi circular key that locates the pulley to the end of the cam.

Moving the cams around ie altering the timing can have a dramatic effect on where in the rev range the engines power is made. One trick on this is to have VVT variable valve timing, so under certain revs the engine is tuned for economy, and over a certain revs the engine is tuned for peak power.

I think they are looking at introducing this on the R1 at some point?
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