I do not ordinarily spend much time thinking much about the workings of the internal combustion engine. But inexplicably, I woke up yesterday wondering about valves. Why on earth did the people who originally designed and built internal combustion engines go for poppet valves, instead of the much simpler solution of rotary valves? Rotary valves, one might think, would be much simpler and more effective?
Usually, with this sort of thing, it turns out that other people have also looked into the possibility, and it turns out that there are rotary valve engines. There is a chap in New Zealand who successfully developed one some years ago. And a company in North Carolina, Vaztec, working along the same lines.
The principle is pretty straightforward. You have a cylindrical valve with a slot in it; as it rotates it either does or does not let the fuel into the combustion chamber. Or, in the case of the exhaust valve, it either does or does not let the exhaust out. Obviously there are engineering challenges. How to cope with the thermal expansion as the engine gets hot? But one would have thought that these are the sorts of issues that modern engineering could cope with?
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phenell 