You don't know what a can of worms you've opened up Stuart:glee:
I absolutely LOVE piston engined 1st and 2nd World War aircraft and all the technology that goes into them........but the engines are really special, as they have to develop so much power, though be as light as possible and of course must be reliable too! A difficult thing to achieve I would think, especially back then.
If you want mechanical complexity, take a look at this beauty!
Its a Bristol Hercules, air cooled, double row 14 cylinder, sleeve valve radial engine. It's a 'normal' fixed engine, with the crankshaft turning in the normal way.
But that's where the 'normality' ends!
This engine powered 2nd WW aircraft, such as the Halifax bomber, the Sterling bomber and the Beaufighter and many others.
You will notice that this 4 stroke engine doesn't use poppet valves as found in, again 'normal' engines, but uses sleeves to uncover ports, not unlike the 2 stroke way. But again, that's where the similarity ends.
After this build up, I hope this link works:confusion:
https://www.google.co.uk/search?sou....64.psy-ab..6.10.1442...0i131k1.0.uwDC2KQxiAw