Hey Pete, thanks a bunch! I read where even the nitrogen pressure will not keep the follower in contact with the cam at high rpm's. As the rpm's increased over the years, they found that they could manipulate this "float" with what they called "ballistic cam design". Variable valve timing along with some very odd cam lobes produce what we have/hear today. This is what I think is so cool about the intricacies of engine design! I love reading this stuff - drives my wife bonkers! Jim
Pete, Thanks for the picture I've never seen one prior to this. Does anyone know why the Desmodromic valve design used by Ducati and others is not adopted in F1? It seems simpler and takes less energy to operate. Andy
Desmo valve are extremely sensitive to tolerances in the valve train. Any clearance at all and the valves don't seal. Too tight and things break. Different materials, wide range of operating temps = One mutha of an engineering problem Erich
Ducati have stuck with their trademark valve operation for the MotoGP Ducati and that thing apparently revs like a F1 engine. Apparently though Ferrari engineers that were consulted by Ducati laughed at them and walked out saying pneumatics was the only way to go ... Pete ps: Over at the Ducati site we discuss desmodromic valve operation here if you are interested.
Thanks for the post, very interesting. I was talking to a salesman at Ferrari of Central Florida several years ago and he said that Renault and Williams were working on magnetic valves, which would allow the engines to rev up to 24,000+ rpm. Has anyone else heard of this? If so, how is this project coming along?
Desmo valve gear was used in racing cars a long, long time ago, the MB 300SLR to name just one. Technology has, for the most part, corrected the valvetrain problems that the desmo system was utilized to overcome, ie. heavy valves, weak valve springs, aggressive cam timing, packaging and metallurgical problems. Like an old 50's racing car, beautiful to look at, warms the heart of us gearheads, fussy to maintain correctly, but no longer leading edge technology.
To much weight at the top of the engine and to much height,if and when they can make it more compact this will be the future valve opperation, The camshafts have a conical shape very hard to grind and have a special coating to reduce friction and stop it wearing so quick, Dale.
Does the F50 have this pneumatic valve system? I was just reading this description and it sounds like it does but it's not clear. http://www.fast-autos.net/ferrari/ferrarif50.html
LOL! You know where else they use ballistic cam design? Briggs & Stratton go kart engines! Actually, B&S makes more racing engines than anyone else in the world...
I very much think not,if you loose the pneumatic system its far worse than loosing your timming belt,there just wire'd valves(springs)reving road car engines to high rpm's is fab but the F50 dosent warrent pneumatics its expensive and risky, Dale.
