Spot the oddity

Yes. Airplane isn't even a word.

In a 50+ page document?

Can't really see anything, though I only skipped through the article.

Well, I'm a little surprised they're allowed to release a 1964 document

- but nothing else. Andy

Propellor very small, looks to be variable pitch anti-clockwise and German. (Hoffman stillin business.) May only be there for demonstration purposes.

Also one valve per cylinder four stroke radial engine.

There were several back then. Pic here of similar (differentmake)

Bit here on the engine.

Yes - see figure 3 of a proper aircraft installation.

It's unusual but not unprecedented:it was done on some rotaries, though these, being petrol, had another system for getting an over-rich fuel-air mixture into the cylinders from the crankcase; sometimes through 2T-type transfer ports, sometimes using a valve in the piston crown.

Ah: this says what I just mentioned.

It was used for real, so nt that much of a failure!

Last paragraph of the ma "As a final summary of the author?s analysis of the Packard diesel engine, it must be emphasized that although the engine burned a much cheaper and safer fuel more efficiently than any of its gasoline rivals, it was too unreliable to compete with them. Even if it had been reliable, it was too small to be useful to the large transport operators, to whom its fuel economy would have appealed. In addition, this mechanism operated on the wrong cycle: 4-stroke, rather than the lighter, more compact, and more efficient blown 2-stroke cycle. Lastly, it was doomed by the advent of high octane gasolines, first used while it was still in the development stage. These new fuels reduced the diesel?s advantage resulting from low fuel consumption, and, in addition, gave the gasoline engine a definite advantage from the standpoint of performance. The Packard diesel was a daring design but, for the reasons analyzed in this chapter, it could not meet this competition, and therefore failed to survive."

Which hardly reads as a ringing endorsement.

Ah, the way it was phrased, I read it as referring to the Monosoupape, which wasn't a failure in its day.