in four stroke engine there is one power stroke for every ___ revolutions' of the cranks shaft 1 2 3 4. What is the full form of SI engine Surya Idiot Suction induction Slightly increasing None of the above. What is the compression ratio of petrol engine 2-3 4-5 18-33 16-20. In four stroke diesel cycle during suction stroke Only air is suck Fuel Air fuel mixture None of the above.