Asymmetrical cam profiles

[mikengine]

I got several hydraulic cam profile masters in my possesion and I would like to know if I have coordinates (lift and degree data) how can I determine which is the opening side of the cam lobe and the closing side?

Do I make the opening side the side where it opens the valve quicker or slower?

How can I determine if I can use this master for my application, if I know my lifter diameter? I know what specifications I need in terms of max lift and duration at 0.004" as well at 0.050", but how do I know if this cam profile I choose will work with the lifter diameter as well as the valve spring?

Is there a book that explains this info in details?

 

[EngJW]

One reason for an asymmetrical profile is to open the valve faster during the time that the valve train is being pushed against the spring loading. Gentler acceleraton is provided on the closing side where the spring has to keep everything in contact.

While the same lift table may be used for either a flat or roller lifter, the shape of the master or lobe would depend on which it is, and also on the roller diameter.

You have to know things like velocties, accelerations, radius of curvature to really evaluate how the profile will work in a specific valve train. I don't know of any single good book, but Rothbart and the new one by Norton are good places to start.

You could send the masters off to someone like Andrews where they have the measuring equipment and see what they can offer.