Sunday, February 17, 2008

I'm HD You're Desmo




This is my buddy Greg, he's Desmodromic. Sexy and Italian, not Greg the motorcycle. Greg is, well, Greg. The motorcycle is a Ducati Monster. Desmodromic is the name given to Ducati motorcycles valve train. The valve train is not like other non-Italian drive trains. It is a system of levers that teeter totter the valves up and down. No springs here!
Ducati claims that when the engine valves are levered open and then levered closed the action is much more percise than when the valves are pushed open and then left to the vagaries of a spring to snap them closed. This allows much more precise adjustment of the engine timing.
Timing is everything be you a comedian or an engine. Timing is important in most everything we do, but I digress. Everything that happens in an engine as it runs is not digital like on/off, one or zero. Each part of the engine has tolerances that are taken up as the engine runs through a cycle. The spark needs to go off slightly before the piston is at the top of the chamber because by the time the mixture of gasoline and air starts to burn the piston will be at TDC (top dead center). Immagine as the engine speeds up and slows down the timing of the spark needs to be changed accordingly. There is a mechanism for this, it's the spark advance in the distributor or some computer thingy, but again I digress.
But a spring can only close so fast. Bigger springs will close quicker but will also take more force to open, enter Desmodromic. The Desmodromic valve system is a mechanism that will open and close the valves as the engine spins faster in perfect timing, a mechanism. Anyway it works, Ducati engines will rev like there is no limit.
As I mentioned before Greg's bike is Ducati Monster. It has no fairing, you can see all the engine and all the parts. Greg owned a Ducati 999, a beautiful fully faired, bright red, Italian speed freak. The bike not Greg. Greg sold the 999 and got the current ride, a Monster.
I think Ducati should have named the 999 the 666, that way they would have the Monster and the Beast. Greg sees no humor in this.

1 comment:

zziggysgal said...

"That bike makes my toungue hard!"

...that is what my best friend of 20 years named Piper would have said.
(she was a 6'2" fully tatted biker chick, may her soul rest in peace)