Extracted text: 4. Why do multi-cylinder éngines have smaller flywheels than single-cylinder engines? 5. What systems are commonly seen on an engine? What additional systems are needed to use an engine as a tractor? 6. Why does a cam shaft run at half the speed of the crankshaft? Illustrate. 7. How do you designate the size of an engine? 8. What will be the total piston displacement in a two-cylinder l100 mm x 130 mm engine? 9. If each cylinder of the above engine has a clearance volume equal to one fifth of the total cylinder volume, then compute: a) the clearance volume; b) the compression ratio. 10. Sketch the. operation of a four-stroke petrol engine, explaining the events at each stage. How will the events differ from those of a diesel engine? 11. Why is there a power stroke for every down stroke of piston'travel in a two-stroke engine? At what interval does the power stroke occur in a four-stroke engine? 12. Assuming a firing order of 1 3.-4-2 for a four-cylinder engine, complete the events in the other cylinders if the events for cylinder l'are as shown in Table 2.3.