"Charles Vincent" wrote in message
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Torn Lawence wrote:
The British made some WWII engines with rotating cylinder sleeves that
had in and out ports cut into them - rotary valves! No poppets. Good
performance, but burned oil and left conspicuous smoke trails, not a good
thing for a warbird to do.

That's what I remember from an engine class, unless I'm hallucinating again.

That was a sleeve valve engine, Harry Ricardo's magnum opus. The Bristol
Hercules and Centaurus. Wear was an issue they never did tackle.

When engines were changed as often as shirts, and as easily as shoes, that isn't
a big issue either, IMHO.

You have always got spares sitting around wherever you stop frequently, and in
an hour or so, you put in a new engine and are on your way.
--
Jim in NC