For well over 40 years, general aviation aircraft have depended almost entirely upon the air cooled horizontally opposed piston engine as the primary means of propulsion. Although a dependable powerplant, this type of engine has seen little change over nearly half a century of usage. To meet the challenge of future general aviation requirements, a new liquid cooled version of the horizontally opposed internal combustion aircraft engine has been developed by the Teledyne Continental Motors Aircraft Products Division. The Voyager engine is a liquid cooled high performance powerplant incorporating a patented lightweight liquid cooled cylinder assembly which provides improved cooling, reduced cooling drag, lower fuel consumption, better wear characteristics, longer life and TBO, and higher altitude capability. This paper presents the detail design of the liquid cooled 4.06 inch bore high compression ratio engine with emphasis on the unique design features and reviews the results of a comprehensive test and development program which has accumulated well over 5500 hours test time to date.
The Voyager 200 is a four cylinder liquid cooled 200 cubic inch engine with a 4.06″ bore capable of producing 110 BHP at 2750 RPM with a high turbulence HTCC combustion chamber at 11.4:1 CR for minimum fuel consumption. This engine has already made aviation history by powering the Voyager aircraft on the historic record breaking non-refueled, nonstop flight around the world in late 1986. A six cylinder 300 cubic inch version utilizes the same cylinder assembly and is capable of being rated at 170-190 BHP at 2700-3000 RPM. Both engines are capable of providing a .375 BSFC across a broad operating range with minimal heat loss to coolant and oil. A brake thermal efficiency as high as 36% has been attained at lean cruise with specific heat loss to coolant and oil limited to only 16% of available fuel energy at best power mixture. A .345 BSFC has been demonstrated on the 300 cubic inch engine under conditions simulating advanced turbocharging techniques at high altitude.
Design and development of the 4.06 inch bore engine served as a technology demonstrator. The basic concept was validated and an experience base was established which will enable the development and introduction of a new family of aircraft piston engines capable of meeting the needs of future general aviation aircraft.