Fijnger Followers
Fijnger Followers
(OP)
As a tyre guy my knowledge of engines is a bit sketchy, so I thought I'd post for some advice.
In MotoGP the engine capacity has been reduced from 990 to 800cc. It is already apparent that rev limits are being raised to recover some of the power.
To do this many teams are using pnuematic valve return systems. I understand that these remove any problems with resonance in coil spring valves at high revs, allowing higher redlines.
It has also been suggested that one team will be using finger followers rather than direct acting cams and retaining coil springs.
My question is; what is it about finger followers that might allow higher revs without switching to pnuematic return?
Regards,
Ben
In MotoGP the engine capacity has been reduced from 990 to 800cc. It is already apparent that rev limits are being raised to recover some of the power.
To do this many teams are using pnuematic valve return systems. I understand that these remove any problems with resonance in coil spring valves at high revs, allowing higher redlines.
It has also been suggested that one team will be using finger followers rather than direct acting cams and retaining coil springs.
My question is; what is it about finger followers that might allow higher revs without switching to pnuematic return?
Regards,
Ben





RE: Fijnger Followers
Rod
RE: Fijnger Followers
http://w
Bob
RE: Fijnger Followers
I just thought of another reason, perhaps for street engines, finger tappets are easier to adjust, OEM dealer maintenance, dontchaknow.
Rod
RE: Fijnger Followers
RE: Fijnger Followers
The original concept was to replace poor valve springs of that era.
I will say that you can turn a Ducati cam in the head by hand (less resistance).
A major advantage of rockers is the ratio change I.E. a .382 cam lift with a 1.5:1 rocker ratio will lift the cam .573
and when you use a roller rocker some of the friction loss is cut down,leaving the spring resistance as a major energy loss.
Cheers
I don't know anything but the people that do.
RE: Fijnger Followers
Oh,Oh, how can you say such a thing
You really have to build a Desmo engine for racing, or race one, to appreciate the worth of the system. Valve durations and lift can be extreme, valve to valve clearances, valve to piston clearances, can be set to a minimum, knowing that the two, will never meet.
The rider can abuse the rev counter, miss gears, and over rev on the down change, knowing that the engine is not going to punch the valves into the head.
It is a big sales point now, but because it works. When a twin cylinder wins the World Superbikes, for as long as I can remember, against all the might of Japan.
Maybe the Desmo system is the difference.
Harvey.
RE: Fijnger Followers
Check out Del West: http://ww