in four stroke engine there is one power stroke for every ___ revolutions' of the cranks shaft 1 2 3 4. Full form of SI Engine Shruti Idiot Suction induction Super ignition None of these. Compression ratio of Petrol engine is... 16-20 17-22 9-12 6-7. In a four stroke diesel cycle during suction stroke Only air is suck Air fuel mixture Fuel All of the above.