America's Round-Engine Warbirds: Airframes & Powerplants of the Military Prop Era | Vintage Aircraft for Collectors & Aviation Enthusiasts

Considering that I was a fan of "America's Round-Engine Airliners," enjoyed Bill Yenne's previous book "Building the B-17 Flying Fortress," and that Specialty Press has a long history of producing detailed and visually stunning aviation references, I had huge expectations for this book. Although it's slightly smaller than the publisher's standard format, and printed on matte, rather than glossy paper, presumably to cut back on publishing costs, it's definitely extremely strong on a visual level. Although there are plenty of photographs of aircraft being assembled, flying, and in close-up, and color photos of restored engines in museums, the main draw is probably the huge number of technical drawings and schematics of all of the engines described within, many of them sourced from original technical documentation. A quick browse reveals an ignition wiring diagram for the Wright Cyclone, sectional views of the Twin Wasp's oil system, an exploded view of the R-1820's propeller shaft and reduction gearing, a sectional view of the Twin Cyclone's supercharger, and a color schematic of the Wright R-3350's fuel injection system.Unfortunately, as a reading experience, it's suffocatingly dry and lacks the charm and narrative drive of "Round-Engine Airliners." Although Bill Yenne definitely feels in his element when he's discussing the origins of aircraft and engine manufacturers, he feels out of his league when describing the evolution and technical details of aircraft and engines. Much of the main text reads like a maddeningly repetitive form letter; paragraph after paragraph essentially boiling down to "(engine model) was rated at XXXX horsepower at XXXX rpm at XXXX feet. It had a compression ratio of X.XX:1 and used an XXXX or XXXX carburetor. The (Engine model) weighed XXXX pounds and was XX inches long with a diameter of XX inches." Descriptions of aircraft variants don't go much beyond "this variant was powered by this engine and this many were produced by this plant in XX blocks."Of course, a lot of technical histories tend to be dry affairs, but many of them are incredibly fascinating at the same time. Compared with its companion volume, there's a serious lack of narrative glue and very little sense of why aircraft and engine variants were forced to evolve with changing circumstances. We're frequently told that a particular engine model generated 50 more horsepower than its predecessor or used a different type of carburetor, or had a slightly different compression ratio. However, we're never really told exactly why these changes were necessary, what kind of innovations made them possible, or what impact they had on the aircraft's performance.What we're left then is a book that's visually stunning (seriously, I could spend hours studying all of the intricately detailed diagrams), but plods along much more than its 216-page length would suggest. Despite having two authors with wildly different tones, "Round-Engine Airliners" is definitely a LOT more well-rounded, cohesive, and enjoyable. For all the talent involved, I'm amazed at how mediocre this book turned out to be.