Well....
Thielert made an entry into Gen-Av with a Diesel(s) and had problems and I believe were bought out. Both Honda and Porsche have dabbled with Gen-Av. Honda showed off a letter of Memorandum Engine with Teledyne Continental a number of years back @ Oshkosh and Porsche designed and certified for production a version of the 911 engine with not a lot of success and got out of the business. If my memory is correct the Thiehert entry was esentially a Mercede's auto engine with a limit on TBO, i.e. new engine @ overhall. What is going on here is China gets a Diesel Gen-Av type engine which is required for UAV's via NATO Heavy Fuel Requirements.
What is disturbing is China also bought Teledyne Continental Piston Engines as well a while back. They are buying up everything they can get their hands on, in this arena. Not Good, IMHO...
http://www.flyingmag.com/news/continental-motors-acquires-thielert-aircraft-engines