This Riggle 4-cylinder inline prototype engine was made by Jim Riggle, of North Dakota, in the 1980s. Jim’s first DOHC racing engine is machined from aluminum and steel bar stock. The engine is 9.5″-long, 7″-wide, 7.5″-inches tall, and is mounted on a running stand that houses all necessary accessories to run and monitor the engine. The setup weighs 27 lbs. It sports a water pump, fuel pump, and a pressurized dry sump lubrication system with a peristaltic oil pump. His custom engineered, fully adjustable, methanol carburetors were typically constructed as singles but often used in pairs. Test results on a dynamometer proved it to produce about 4.5 hp at 15,500 revolutions per minute.
Subsequent engines, resembling the Offy style, were constructed from his aluminum mono-block castings, and each bore the name “RIGGLE” on the cam covers. He used his creations to power his radio-controlled race cars and boats, Eventually, he built a radio-controlled Sprint car complete with his version of a NOVI V8 engine. Engine courtesy of Wayne and Nyla Kilber.