Scale Model Running Challenger Flathead V8 By Ron Colonna
Challenger V8 Ignition: Spark Bore: 1 in. Stroke: 1 in. Displacement: 100 cc Max RPM: 6,000 This engine was built early in my gasoline engine building career. I received the castings and drawings as a Christmas gift from my wife. I had it running about five months later. This is the engine that creates the most interest at the shows. So much so that I've had to rebuild it twice because of wear. As designed, it had some major shortcomings. The conrods were bronze castings which promptly wore grooves in the crank. These were replaced with rods machined from 2024 aluminum. Pistons were remade and the engine fitted with rings made from the George Trimble method. Oil control rings are a necessity as the engine smokes badly without them. An electric start system was added and the engine now runs with the push of a button.
4 Cylinder OHV Engine
A short video showing the new stainless collector/header that I made. I had wanted to do this for some time but didn't have much luck bending the tubing. I built a tubing bender and finally made the parts. It is silver soldered together. The sound has changed somewhat but the video doesn't do it justice. This movie clip is from the carburetor/distributor side of the engine. You can see the distributor advance when the throttle is opened.
Scale Running Model Harley Panhead Engine by Ron Colonna
V-Twin Panhead Ignition: Spark Bore: 1 5/16 in. Stroke: 1 1/2 in. Two Cylinder Four Cycle No Castings Used This engine was scratch built to a scale of 2/5ths or 40% of full size. The bottom end was taken from a drawing of a Knuckelhead engine that I puchased on e-bay. The top end was patterned after photos taken from e-bay of Harley parts for sale. I also bought a Harley repair manual that helped with the oil system. The crankcase was split into three sections instead of the usual two for ease of machining. The ignition is solid state and I use a GM coil which fires the two plugs simultaneously. Timing is advanced and retarded with the timer body. Two rotating magnets fire a Hall effect device at the proper times as per full sized points. The engine is large enough to produce that lovely V-twin sound.