Mazda has a super interesting way of doing this. When paired with an electric motor/generator, they can speed up/slow down specific parts of the combustion cycl

Mazda has a super interesting way of doing this. When paired with an electric motor/generator, they can speed up/slow down specific parts of the combustion cycle to essentially get vvt. I think they can only really do this as a range extender due to the fact it makes power delivery a little bit weird. https://carbuzz.com/news/mazdas-new-rotary-engine-variable-valve-timing-is-weirder-than-the-wankel-itself/ https://carbuzz.com/news/mazdas-new-rotary-engine-variable-v...