Microwave Diagnostics of Intake and Exhaust Valves

The object of microwave diagnostics is to provide accurate, noninvasive measurements upon engine. This paper deals in particular with experiments performed upon the valves of a Buick V-6 engine. A microprocessor controlled data processing system is described that (1) collects and stores, in digital form, the microwave signal developed during several engine cycles (2) produces a very high resolution computer print out of the stored signal correlated with engine crank angle, and (3) outputs a printed analysis of every microwave resonance found in the signal. Exhaust valve motion produces a directly related shift in the crank angle position of a resonance. The magnitude of the shift in the TE111 mode resonance is 7 degrees for one cycle in the change of this valve. The maximum displacement of this valve into the cylinder is .200 inch. A displacement of .005 inch can be measured.