By Randy Dufault
William Piper introduced his J-3 Cub with a Continental A-40 engine. And as often is the case, that first powerplant just did not have enough horsepower to make the Cub perform as its designer believed it should.
But up front on WAAAM's Cub at this year's EAA AirVenture Oshkosh is a Lenape Papoose LM-3 three-cylinder radial engine, a part of what the organization believes to be the largest collection of flyable three-cylinder-powered airplanes in the world.
"The A-40 makes 37 hp," said Western Antique Aeroplane and Automobile Museum (WAAAM) chief pilot and curator Ben Davidson. "When Lenape came up with this engine that made 50 hp, Piper put one on [a Cub]. Fifty hp is actually quite an increase, and this performs pretty good.
"The biggest problem with this engine is that Lenape recommends an overhaul every 200-300 hours. It didn't turn out to be the most reliable [option]."
Papoose-powered Cubs carry the designation J-3P. Piper typically suffixed J-3 models with the first letter of the engine manufacturer's name. A Cub with the J-3L designation already denoted a Lycoming-powered craft, so the Lenape-powered planes invoke the engine model J-3P, for Papoose.
Piper built between 13 and 30 Cubs with the little radial. Three remain on the FAA's registry, with WAAAM's being one of two known to be in flyable condition.
Prompted by the 75th Anniversary of the Cub design being celebrated here at EAA AirVenture Oshkosh 2012, WAAAM decided to bring its rare bird. Only it hadn't flown in 21 years.
But the engine started right up, and after a few test flights, the plane was disassembled for a road trip to Hartford, Wisconsin.
When asked why WAAAM chose not to fly it all the way here from its home in Hood River, Oregon, Lee Borchers, a WAAAM pilot who flew the plane in the Cub mass arrival this past Sunday, pointed at the windshield.
"This is 45 miles," Borchers said. The windshield was almost completely obscured by oil. "They are so rare...it would be taking quite a chance. It could have been done, but I think it might have taken the same amount of time (as driving)."
It took 10 hours of concerted effort to assemble the plane in Hartford.
"I don't know how many people worked on this airplane with me [last Saturday], at least eight to 10," Borchers said. "But I tried to let all of them fly it before it got dark. I had a lot of help."
WAAAM founder Terry Brandt acquired the Cub in the 1980s. A core feature of the museum's collection of 82 flyable aircraft is a number of unique powerplants like the three-cylinder radials.
Engine reliability and a reputation for excessive vibration likely contributed to the model's short life, though Davidson doesn't believe the power option is much different than other Cub versions.
"I think it is a pretty good-running airplane," he said. "When you take off, it performs just as good as a stock 65-hp Cub."
Davidson went on to say Beverly (Bevo) Howard used a Lenape Cub in an air show routine. Howard is credited with executing the first ever Cub outside loop with the Papoose-powered version.
WAAAM's J-3P is parked just east of the V Red Barn.