Camshaft friction

[Suavemechanic]

i would suggest some research on 50 cc scooter clutches and the auto gearing systems they often have a centrifical hub that expands with rpm to change the gearing. you could possiblbly reverse engineer something to ramp up a cam....and the little fly weights are cool !

[Drew]

I saw the start of this thread & thought of the same idea Bill mentions.
The biggest drama is if its on the exhaust cam of a 4age your dissy or cas will advance or retard with the cam.

[mullett]

Thank you all for the replies! I really appreciate it.

First of all, the reason why I'm looking into it.

I have for a while wanted to develop a concept for vvt mechanism that can work for any engine, that is to say, a straight bolt on camshaft pulley where all the parts and the mechanism itself is conatined within the gear it self. This of course means that the mechanism would have to be powered by any forces wich can be harnessed inside the gear. In my head it would be a mechanical design able to phase the camshaft to smooth out the torque curve. To be able to use any force for this purpose it must change with the rpm of the engine. This is why I'm looking into this particular aspect. If I can come up with a cheap effective design, my plan is to make it into a business, but that is in the future. I'm currently an economics student so I have no resources or workshop to do any experiments, and that is why I have to rely on you fine people.

Which University are you at? You'd probably do very well to take a walk to the Mechanical eng building and find a lecturer in dynamics (or machine dynamics) to talk to: they'll probably be able to help you solve the forces mathematically. To make it truly universal will be very difficult, and I imagine that stepper motors would be the only viable way. Hydraulic pressure is probably too difficult to rig and bulky.

You might do well to find a factory VVT engine or engine paper that you can really get stuck into, I think it will turn out to be very much a black art.