Radial Engines

A Radial Engine is a type of reciprocating internal combustion engine. Not all round engines are radial engines, so don’t let looks fool you. The cylinders are arranged to point outward from a central crankshaft like the spokes on a wheel. The reason for this design was mainly for cooling. A radial engine with all the cylinders out front can use air to cool the cylinders as opposed to the inline type of engine which relied on water to cool the engine. The inline type required a radiator and coolant which contributed to extra weight. This and other factors gave the radial engine a greater power to weight ratio. The radial was popular largely due to its simplicity and power to weight ratio over the inline water cooled engines.

Additionally, radials offered higher mechanical efficiency than inline engines, as they had shorter and stiffer crankshafts, a five-cylinder radial needing only two crankshaft bearings as opposed to the seven required for a six-cylinder inline engine. The shorter crankshaft also produced less vibration and hence higher reliability. Another advantage of the air-cooled radial is that all cylinders receive equal cooling airflow.

Four stroke radial engines always come in odd numbers of cylinders because so that a consistent every-other-piston firing order can be maintained, providing a smooth running engine.

We have three radial engines in our collection. This does not include the radial engines powering our aircraft collection.

• Kinner B1
 
• Lenape Papoose
 
• Lenape Chief Experimental