n - heptane

iso - octane

benzene

alcohol

higher

lower

same

depends on fuel quality

bigger flywheel

smaller flywheel

same size of flywheel

no flywheel

automatic ignition of the charge at the end of compression

ignition induced by the passage of a spark

ignition of the charge before the passage of flame front

ignition induced to supplement the process of normal combustion

reduce the resistance to sliding that occurs between the cam and the tappet.

allow for lengthening of the valve owing to the heat of combustion

increase the speed at which the valves move up and down

make the crankshaft turn smoothly