The Older Gentleman wrote:
... - like many other aero recips
it's limited by 0.9 c at the prop tips at the top end of the tach.

Didn't the Harvard's prop tips go supersonic?

....
Low compression heads on the Merlin
were the choice for civil airliners post war.

Hm. Makes sense. That said, Merlins were hardly used in 'proper' civil
aircraft. The York and the Lancastrian, of course, both of which were
Lancaster variants. And the Tudor, which was a failure.

Can't think of any others, though I'd be delighted to be informed. Most
of the piston-engined civil airliners I can think of used air-cooled
radial engines.


Here's Wiki's idea of the direct uses: not to mention tanks, boats, and
a car (!)

* Armstrong Whitworth Whitley
* Avro Lancaster
* Avro Lincoln
* Avro Tudor
* Avro York
* Boulton Paul Defiant
* Bristol Beaufighter
* Curtis P-40 Kittyhawk
* de Havilland Mosquito
* de Havilland Hornet
* Fairey Barracuda
* Fairey Battle
* Fairey Fulmar
* Handley Page Halifax
* Hawker Hurricane and Sea Hurricane
* Hispano Aviación HA-1112
* North American Mustang X
* Short Sturgeon
* Supermarine Seafire
* Supermarine Spitfire
* Vickers Wellington
* Westland Welkin

Aircraft with sonic tips have a noisy bark....

Brian W