I donno why, but I was on a piston engine kick tonight, and spent too much of my free time researching various WWII engines online. The questions began to mount.

Messerschmidt's ME-109 was particularly interesting. I was reminded of its inverted V12, and wondered if an inverted engine suffers power losses because its power stroke must work against gravity. My armchair engineer imagination tells me that working against gravity on a power stroke is no less costly to overall power than doing the same on a down stroke in a right-side-up engine, to say nothing of the tiny impact gravity might have on the powerful power stroke of an inverted 1500+ engine. After all, some WWII submarine diesels were inverted for some reason, and those things were slow revving and must have had very heavy pistons and rods. But perhaps some of the REAL engineers here can confirm my imagination.

Radial engines have always puzzled me with their seeming complexity. What is the advantage of having, say, 9 cylinders arranged in such away as to have essentially 9 separate banks, thus requiring and equal number of separate valve train and lubricating components? I suppose compact packaging is a major plus, and even necessary with engines over 12 cylinders. And i suppose it would also be impossible to air-cool a many-cylinder V engine.

But still, I'm curious about the inherent advantages and disadvantages of V and Radial designs. Are their any unique solutions to either that have been employed in little-known recip engineering experiments? Thanks for your replies.

O