According to Hummel associate Scott Casler, "We take a 4-cylinder VW engine, cut it in half and use the front two cylinders. We make three engines: 28-hp, 32-hp and 37-hp models. The only difference between the engines is the displacement. The cases for the engines are purchased reconditioned or are available new. All the other parts - cylinders, pistons, heads, cams, etc. are new."
The engine uses the standard VW wet sump oil system. A Zenith updraft carburetor is used with a unique heating system to help prevent carb icing. The oil lines are wrapped around the fuel intake.
Ignition is supplied by a single magneto. The prop is spun direct drive. Total weight of the 1/2 VW engine is 85 pounds. According to Casler, the engine is suitable for ultralight and light Experimental aircraft. The engine can currently be found installed on miniMAXes, Hummel Birds and Skyraiders, and of course the new Hummel Ultra Cruiser.
"With regular maintenance and oil changes you can go 1,500 hours between rebuilds," continues Casler. "Rebuilds are very cheap, you're looking at about $250 in parts. These are all off-the-shelve VW parts."
The engines are currently priced at $3,250 for the 37-hp model, $2,700 for the 32-hp model and $2,400 for the 28-hp model. These prices are for ready-to-run engines. They can also be built from plans and parts available from Casler. Phone: (419) 335-2147 (419) 335-2147
The Ultra Cruiser
While the Ultra Cruiser uses the same all-aluminum construction as the older Hummel Bird, it is a completely redesigned aircraft. It has been lengthened and lightened for better ground stability and to fit into the U.S. ultralight category, according to Hummel Aviation.
The Ultra Cruiser uses 6061-T6 aluminum rivet-together construction. Currently the plane is only available as plans-built, but preformed parts should soon be available.
The average builder constructing from plans should be able to complete the project in about 800 hours, using standard metal tools. A construction and flying video is available. It is anticipated the plane will be available ready-to-fly in the near future.
According to Hummel, the Ultra Cruiser can be operated under FAR Part 103 when powered by the 4-stroke 1/2 Volkswagen engine. The plane has a canopy and cabin heat for all-weather flying. The canopy can be quickly removed for summer flying. The wings are detachable for storage.
Wingspan of the Ultra Cruiser is 25 feet, with a length of 17 feet. Stall comes in between 25-28 mph, empty weight is 249 pounds, and gross weight with a 170-pound pilot is 450 pounds.
Info: Hummel Aviation, 509 East Butler, Dept. UF, Bryan, OH 43506. Phone: (419) 636-3390