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Hummel Engines

Hummel Engines

Based in Coolidge Arizona, US. Hummel Engines is modifying the original Volkswagen air-cooled engine for use in small, personal aircraft.

Morry Hummel's 1/2 VW engine conversion plans have become a trusted standard in the aviation community. The original Hummel conversion has been refined over time, allowing larger displacement and the options of NiCom aluminum cylinders, dual ignition, alternator and electric start.

VW Derived Engines

2 & 4 Cylinder Engines

Hummel Two Cylinder Engines

The Hummel two cylinder VW engine is powering the Hummelbird, Ultra Cruiser and other experimental amateur built and ultralight aircraft, these engines have become the standard in the experimental aviation community.

Scott Casler's VW conversions are available for many popular homebuilts and Light Sport Aircraft. Hummel Engines have powered aircraft designs like the Sonerai, Sonex, Ultracruiser Plus, Aerosport Quail, Avid Flyer, Corby Starlet and others. They are now building TEAM SuperMax.

Engine ModelHorsepowerBore x StrokeDisplacement
2 Cylinder Models28 hp88 x 69 mm840 cm3
32 hp92 x 69 mm917 cm3
37 hp92 x 78 mm1037 cm3
45 hp94 x 86 mm1200 cm3
4 Cylinder Models50 hp85.5 x 69 mm1600 cm3
60 hp92 x 69 mm1835 cm3
76 hp92 x 82 mm2180 cm3
85 hp94 x 86 mm2400 cm3

Engine weight for the two cylinder varies between 81 and 103 lbs, the four cylinder weighs between 135 and 167 lbs.

Machining Services

Hummel Engines has the capability to perform the machining operations required for VW conversions, maintenance and upgrades. Contact the owner, Scott Casler, with your requirements for a price quotation.

Engine Seminars

Speaking in forums and clinics at several national and regional aviation events, Scott Casler has established himself as the leading source of half VW conversion information and related products. With hundreds of hours of VW based flight time and a full line of parts and services, he has the experience and knowledge required to support your VW conversion.


More detailed information and history about the VW air cooled engine can be found at its Wikipedia page.

Company information

Hummel Engines can be visited and reached at:

Hummel Engines, Scott Casler
5464 East Storey Road
Coolidge, AZ 85128 USA
+1 520-723-5283
See contact page

Text and images used with permission (pending) of Hummel Engines.

Written by EAI.

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