GRAHAM WARWICK / WASHINGTON DC
Dyna-Cam plans to develop range of products with reduced noise, almost zero vibration and lower fuel consumption
A new engine type entering production for kitplanes could find its way into production aircraft. The Dyna-Cam is a cam-drive free-piston engine which is more compact, lighter and smoother, and produces higher torque than conventional reciprocating powerplants.
The conventional crankshaft and piston rods are replaced by two engine blocks, each with six cylinders arranged around a main shaft. Six double-ended, free-floating pistons shuttle back and forth between the cylinder blocks, and fit over a sinusoidal cam which is keyed to the central shaft.
Torrance, California-based Dyna-CamEngine plans to develop a series of powerplants. The first, designated the DC-375, is a 150kW (200hp) engine 330mm (13in) in diameter, just under 1m long and weighing 135kg (300lb). The engine is lighter than the equivalent IO-470 piston powerplant and produces twice the torque.
The Dyna-Cam produces its maximum torque at a lower RPM than a conventional engine, and can drive a larger, slower-turning propeller that produces less noise. MT Propeller has developed a four-blade unit for one of the engine's first applications, a Lancair kitplane, says Dyna-Cam chairman PatWilks.
Other potential advantages of the Dyna-Cam engine include "almost zero vibration", says Wilks, and lower fuel consumption compared with conventional piston powerplants.
The Dyna-Cam has its origins in a torpedo motor design. "Close to $10 million" has been spent so far developing the engine, estimates Wilks. While production has started for the kitplane community, plans to enter the certificated aircraft market were set back when aircraft modifier Riley Superskyrockets withdrew from an agreement to replace the front engine on a Cessna 337 piston twin with the DC-375.
Dyna-Cam may proceed with plans to re-engine a Cessna 185, but admits that installing the DC-375 in a piston single will require a more expensive certification effort.
Source: Flight International
