Continental
Thanks to their complex and high-pressure nature, diesel (Jet A-burning) piston engines are premium devices full of expensive parts, and their penetration into the amateur-built world is essentially non-existent. Some sophisticated, powerful and very fuel-efficient Jet A reciprocating engines such as the R.E.D. V-12 and exciting but currently in hiding Graflight V-8 have been developed, but their high purchase price and their makers’ reticence to sell to individuals (not well-connected in aviation) due to the complexity of properly integrating them into an airframe mean they’re really not in our game.
Meanwhile, Continental has a surprisingly well-populated line of certified diesels as they’ve bought diesel programs started by Thielert, Austro and other European outfits. At least technically these engines are suited to larger homebuilt aircraft (they’ve been used on Cessna 182s, for example), but their economics make them viable only after flying many hours, not the typical sport plane operating profile.
