Mr Porche designed it well .
The longest production run of any engine, to my recollection, in the world .
Only needed " electronically controlled ignition " , to bring it to modern specifications.
Cheap to run & maintain.
Half a litre of oil per change , and six litres of fuel per hour to fly .
" 10,000 miles is recommended oil change for cars " .
but most change at 7,500 miles .
If you object to VW-Porche look at Subaru . If you can carry that weight . 150 to 200 klgm
38.5 kgs " air-cooled VW " ( 2 cylinder ) 36 hp .
spacesailor