Duke Engines – 5 Cylinder 4 Stroke 3 Injector Valveless Axial Engine

Duke Engines are in an advanced stage of developing a unique high-speed, valve-less 5 cylinder, 3 injector axial internal combustion engine with zero first-order vibration, significantly reduced size and weight, very high power density and the ability to run on multiple fuels and bio-fuels. The Duke engine is suited for many uses including marine, military, automobile, light aircraft and range extender applications.

The Duke’s nutating reciprocator leads to very low angles of con rod articulation resulting in a near sinusoidal reciprocating motion. This combined with the counter-rotating cylinder group and crankshaft in the Duke engine delivers near perfect mechanical balance resulting in a very low vibration engine.

Duke Engines reciprocator and crankshaft

The pistons are all attached by their connecting rods to a reciprocator which rotates as a result of the movement of the pistons and is itself attached to the crankshaft which rotates in the opposite direction. As the pistons move through their strokes, they also move past the ports, injectors and spark plugs, eliminating the need for valves. It’s a very ingenious arrangement.

Duke Engines internal components

The axial engine has a number of interesting features:

  • The counter rotating components generate very low vibration
  • Only 3 injectors and plugs for 5 cylinders plus no valve train reduces the parts count
  • It is designed to run on a wide variety of fuels
  • Lighter and more compact than similar displacement conventional engines

Watch the videos to see the internals in motion and how it works and also note the balanced coin on the running engine as it is repeatedly revved.

Source: Duke Engineering