RideLust

This 1981 video is chock full of gear head goodness: a Cosworth engineer explains the problems of high speed valve operation, then shows what happens to a Cosworth DFV motor when an intake valve spring breaks, Good stuff, and a great example of why we change timing belts punctually on interference type motors.

I love his pitch for desmodromic valve actuation at the end of the video, accompanied by some all-internal Ducati motor porn.

Found on Bangshift