Achates Opposed Piston 2 Stroke
 

Thoughts anyone on a aeronautical application?

Numbers being talked about are double the efficiency over the best diesel engines today.

I stopped listening when he said "rather unique".

Presumably they have spent the two years since that video was made studying their history books ...

Hugo Junkers would be rolling in his grave. Concept already widely used on trains and ships, google "Deltic".

https://oldmachinepress.com/2015/09/...rcraft-engine/

I think he probably means “rather unusual” because something is unique, or it’s not unique.

Anyway, a child I used to enjoy the sound of the Commer “knocker” truck engines (and in some buses). A Deltic locomotive ran through our village just a few days ago, the sound is very distinctive.

Superior Air Parts had a proposal to market two versions of a three cylinder opposed piston aircraft uncerified engine as recently as 2015 rated at 100 and 125HP, seems now to have been withdrawn as their web site now makes no reference. As for unusual or unique, no, I wouldn't call sleeve or desmodromicvalves, or turbo compounds unique or unusual either. Perhaps I've lived too long and seen these "unique and unusual" pieces of machinery in daily use earning some body a living.

It seems this engine will be in the next version of the Abrams tank. Uncle sam is picking up the tab for the development.