In the present experimental work a computerized Single cylinder Diesel engine with data acquisition system was used to study the effects of oxygen enriched air intake on Ignition delay and Heat release curves. Increasing the oxygen content with the air leads shorter Ignition delay, elevated heat release curves and the ability to burn more fuel at the same stoichiometry. Added oxygen in the combustion air offers more potential for burning diesel. Engine test have been carried out in the above said engine for different loads and the range of ignition delay and Heat release curves with respect to different percentage of oxygen enrichment was discussed.