Now
this is an engine I'd like to get my hands on. V2 860 cc, 25 hp, 45 Nm diesel. There are 22 hp versions as well. These engines seem to be made by a few companies in China, eg. Longfar ('LongPower'). As to whether they are clones of some or other more well-known engine or a fresh Chinese design I don't know but I do know that one of these in an Ural would look fine. It reminds me a bit of a Moto Guzzi engine. Knowing that the Guzzi engine started life as an industrial engine for cement mixers and such this comes as no surprise as that is one of the intended applications for these Chinese diesels as well.
These engines sell for between $700 and $850 FOB Shanghai or some other Chinese port. Minimum order quantity seems to be 5 though, maybe they will agree to selling an evaluation engine...