The heart of every Pietenpol is its engine. Chemical energy is converted to kinetic turning an airfoil (the prop), this produces thrust, thrust opposes drag and our mighty craft is propelled through the air bringing us to exciting and far away destinations at the break neck speed of about 69 knots (80mph). Originally Piet's were powered by a 45 horsepower converted Model A Ford engine which although sounds cool is grossly underpowered and unreliable. Most Aircampers using the Model A engine end up being donated to a museum. Also popular is a converted 100 horsepower Chevy Covair engine. Although this powerplant has ample power, my research found they are plagued with cracked crankshafts and I don't have the time to find and rebuild one. Some folks use four cylinder 60 or 80 hp Continentals or Lycomings with good success. These engines were used mostly in Piper, Cessna and Aeronca aircraft of the late 40's and 50's. They are fine engines but are unable to power an aircraft electrical system and are slightly underpowered.
An excellent candidate was 110 hp. water cooled converted Honda Fit engine made by Viking. These engines are reliable, quiet, affordable and at 3.5 to 4.5 gallons per hour sip auto fuel. The negatives are the Viking has a gear reduction system that requires the use of a special three bladed prop. Also, it would require a modern streamline cowl that would not fit the look of an airplane from the 1930's
The most likely choice for our powerplant was made by my wife and daughter. They requested a "round" engine. After some research I found the Rotec R-2800. The 2800 is a modern 110 hp. air cooled 5 cylinder radial aircraft engine made by Rotec form Australia. It's not quiet, not cheap and burns about 5.5 to 6 gph... but man does it look and sound cool. Finished off with a KitFox bump cowling, along with a wooden prop and our little plane should look like it came straight out of the art-deco era of the fabulous 30's.
