VALVE TRAIN INVESTIGATION FOR CNG ENGINE APPLICATION

Abstract

Compressed natural gas (CNG) beyond doubt has better emission byproduct as compared to
pe trol f or compress ion igni tion eng ines [1]. For greener environment retrofitted or converted
vehicle was introduced into the automotive market. This work inv estigates whether the valve
overlap pe riod affects the vehicle eng ine performance. From the study, it was f ound that for a
single overhead camshaft eng ine, the valve overlap period does affect the engine performance.
The results show that retrofitting the pre sent veh icle without modifying the valve overlap period is not suitable fo r CNG. It reduces the eng ine performance by about 9% f or part open throttle conditions as compared to petrol. The present overlap duration should be increased fo r better performance.