Anyone actually had a timing belt fail

Give a gold star to Vincent. I was wrong, 4 valves per cyl. dates back to at least 1908. Ferrari started to use cup and shim valve followers in the mid 60's, those go back to about the same time. It's a shame it took almost 60 years for them to get on board. I don't wear blinders and look to Ferrari to always lead the way. Some things they do well, others they do not. And if you are claiming that belts are more reliable than chains, that is just silly. And your experiences just prove one thing, some people can break a steel ball.

 

I would like to offer one plus for a chain system. The one used on a Datsun 240Z. It has a spring loaded tensioner and three cam pulley positions to compensate for any variables. Very dependable, never heard of one failing.
They also don't take a 'set' like belts.

It is my understanding that belts are prefered for high performance applications because thay are light weight and have less inertial mass to hamper sudden changes in RPM's.

 

Although we have usurped this thread, didn't mean to do that.

Just to point out that "chains" as used in Ferrari V12 (2 valve for sure) were expensive to maintain in top form and that replacement of the fibre belts by the maintenance schedule is not as big a deal as some make it seem.

I don't look to Ferrari to be the leader in technology either ... seldom have been.

Thanks for the info on F355 didn't know that! I really stopped keeping up with things somewhere around the 308.

And yes, I can F*** Up an anvil!

Best wishes