The Generac "Big Twin" generator engine has been adapted for aviation, installing a toothed belt PSRU.

“Front view of an installed Big-Twin”

-The engine has two air-cooled cylinders in V.

“Big-Twin side view”

From Appendix 10: This brand builds 2V, OHV (Over Head Valves) industrial engines, in concrete the four-stroke Big-Twin for a new application, currently in progress.

"Generac 2V on a new construction"

-It is used by Valley Engineering, as we said it is a Generac industrial engine, which is adapted by belt reduction gear.

"A Generac engine with belt reduction"

-Some applications keep the cylinder bodies surrounded by baffles for cooling and in others they are disassembled, relying on the air from the propeller or the advance of the aircraft.

"Reduction belt with a tensioner"

--It is easy to confuse a "Briggs & Stratton" with a "Generac" if you do not know the minimum details.