Timing belt CVT Variator? (Concept)

[jonlasaga]

Hello all. I just saw a really interesting video and would like to hear your opinions on it. This channel two stroke stuffing is trying to create the fastest two stroke ever. He runs it in a no ferring class on some salt flats. His channel is super interesting and I highly suggest you check it out if you enjoy engine builds. Anyway though his entire engine is homemade its a 50cc with a billet case, an oko carb, and custom cast internals and head that he has videos of him making at home. On nitro methane it apparently makes 20hp so with the standard single variated cvt from comet that he uses he is experiencing power loss and slip trying to reach a high top speed. His solution is this timing belt cvt variator that he shows in this video here.

https://youtu.be/K0KhU72jewM

Now I dont know much about these cvts as i have not worked with many of them. I have heard that you lose about 20% of your power to these v belt cvts that we commonly use on karts and his solution to this issue is to create a variator that works with a timed belt. In my opinion it sounds like a great idea as it would give you alot more grip than a standard belt but I dont know if this is has been done before. Does anyone know of something on the market that is made like this? And what are your thoughts on this design he shows?

 

[Karts of Kaos]

i watched that video and it seems like a good idea. but i found a problem with is design, i dont see a way to idle.

 

[65ShelbyClone]

I watched...most of it. Idling isn't that big of a problem for a land speed vehicle. They can be push-started and then run into the shutdown area. A big problem is if the engine blows at top speed and locks the drive wheel. Down you go.

One potential problem I see with the design is that the sliding toothed segments are going to create a timing pulley that has nonuniform pitch over large areas of slider travel. His variator design would have to be more like a geared transmission with discrete steps and not constant variation.

 

[jonlasaga]

i watched that video and it seems like a good idea. but i found a problem with is design, i dont see a way to idle.

That is true it would be hard to make it idle but he could put slots in the bottom of the cvt so that the teeth can slide far enough back that its flat and still slips but that might mess up the rubber geared parts on a timing belt.