Compact tuned exhaust system for aircraft with reciprocating engines

Abstract

A tuned exhaust system for a multi-cylinder, reciprocating, internal combustion engine is disclosed. Each exhaust tube has approximately the same overall length resulting in a predetermined resonant frequency. The overall length includes the sum of the header tube length and the internal length of the collector assembly portions of the exhaust channels in the heat exchanger box. Calculating the correct length and bending the pipes to fit in the space available resulted in increased horsepower, reduced fuel consumption, cooler cylinder head temperatures, reduced noise and vibration for four-cylinder and six-cylinder aircraft engines.