Sakin i think the rotatry engine has a lot more to offer too. If only the gurus put more research into it we know the success this engine got with the rx's so siguro more research lang it'll click.
By it's own design, I think the rotary engine has it's own limits. The engine is too sensitive to pinging so you have to run it richer than it should to prevent it destroying itself. This leads to emissions higher than what would be acceptible.