Neat video. That uses the same basic principal as the Lycoming XR-7755 engine, which was made in 1944, only it used axial switching of cams. Guess it's an old idea.
"Lycoming XR-7755 This behemoth is the largest piston aircraft engine ever built in the free world. From 7,755 cubic inches (bore of 6.375", stroke of 6.75") and 7,050 lbs it gave 5,000 horsepower under test in 1944; 7,000 horsepower was the development target. Nine liquid cooled inline four cylinder engines about a common crankshaft. Two contra-rotating prop shafts. The camshafts each consisted of two sets of lobes. One set of lobes for takeoff, the other for economy cruise. The camshafts were shifted axially to switch lobe sets. 580 gallons of fuel per hour at takeoff power, BSFC of 0.43 at cruise. Paul McBride of Lycoming says it was for the B-36 but political pressures caused the B-36 to be fitted with the Pratt & Whitney R-4360 instead. Awesome. A survivor still exists at the Smithsonian's Garber facility. See it if you can. Circa 1944."