What I am surprised by is that cams are still used to operate the valves.
Given to how precise these need to be these days, I would've guessed they would've switched to electronically actuated valves.
Given to how precise these need to be these days, I would've guessed they would've switched to electronically actuated valves.
The exact valve timing isn’t really a big factor in emissions as much as temperature control and exact AFR control. I mean valves need precise timing to avoid coming into contact with pistons but if you’re already at that level of precision then you gaining more precision won’t really reduce your emissions.
Of course being able to change the timing of your valves helps with both efficiency and emissions, but VVT does that pretty well.
And here's an example of someone that retrofitted a Miata to use a similar [air-actuated valve system](https://youtu.be/E9KJ_f7REGw)
Kinda, it's all continuous variable valve lift now: