Search Results

For upgrading/new engine development, the piston and cylinder head are the most exposed members due to amplified mechanical and thermal loadings. Mechanical loading is basically due to the combustion gas pressure in the combustion chamber and its scale can be judged in terms of peak cylinder pressure. Thermal loading is due to temperature by heat flux acting on the piston surface, cylinder liner and the cylinder head. The importance of the various loads applied on the head and cylinder block in operation was assessed and a method of predicting their influence on the structural integrity of the components described by doing actual test on engine test bench. Therefore, it’s very important to have thermal survey of the engine. The engine thermal survey test was primarily developed to measure the temperature in the head of the engine to determine if the temperatures that are measured are within the design guidelines for appropriate engine operation.

There is a two-step migration in the Indian automotive industry from Bharat stage IV to Bharat stage VI emission norms. This emission regulatory migration demands substantial engineering efforts to design, develop and validate engine, engine components, and complete exhaust after-treatment system. In this context, cylinder bore distortion plays a vital role in engine blow-by, oil consumption, and its effect on DPF ash loading. For Bharat stage VI engines, overall thermal loading is increased which exerts higher mechanical and thermal stresses over the engine and subsequent components. Increased engine bore distortion has ill effects on the engine and after-treatment devices. Reduction of bore distortion helps piston rings to confirm with the bore, which results in low oil passing through rings towards the combustion chambers which finally results in low oil burn off in the combustion chamber.

Injector nozzle coking can severely limit engine performance by limiting the amount of fuel delivered to the combustion chamber and altering the spray pattern. Injector nozzle coking is also one of the most sensitive measures of diesel fuel quality. Formation of deposits within the holes of the injector nozzle or on the outside of the injector nozzle may have an adverse effect on overall system performance. There is no single factor that results in nozzle coking but can be classified in four major areas e.g. spray hole geometry, application duty cycle, nozzle localized temperature and the fuel quality. This paper provides a critical review of the current understanding of the main factors affecting the deposit formation. Engine was tested by motoring dynamometer using test cycle generated by Cummins Inc, as an attempt to try to simulate field conditions.