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Old January 10th 06, 04:33 PM posted to rec.aviation.ifr,rec.aviation.owning,rec.aviation.piloting,rec.aviation.student
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Default Engine Making Metal (Was: Nasa Icing courses)


Lycoming is starting to offer roller tappets.


Roller tappets however will increase the Herzian compressive stresses
on the cam (and on the roller) when compared to a flat tappet surface.
It isn't necessarily a cure all.

I suspect radial engines use roller tappets because of the
comparatively high velocities between the cam and the tappet.