Howstuffworks.com
More displacement means more power becauseyou can burn more gas during each revolutionof the engine
This can be accomplished by making cylindersbigger or by adding more cylinders
Higher compression ratios produce morepower, up to a point.
The more you compress the air/fuel mixture,however, the more likely it is to spontaneouslyburst into flame (before the spark plug ignitesit).
more air (and therefore fuel) into a cylinder
the same way that you would by increasing thesize of the cylinder
Turbochargers and superchargers
Compressing air raises its temperature
you would like to have the coolest air possible
the hotter the air is, the less it will expandwhen combustion takes place
intercooler is a special radiator through whichthe compressed air passes to cool it off before itenters the cylinder
Air resistance can be lessened dramatically byputting two intake valves in each cylinder
Some newer cars are also using polished intakemanifolds to eliminate air resistance there
Bigger air filters can also improve air flow.
Air resistance can be lessened by adding asecond exhaust valve to each cylinder
If the exhaust pipe is too small or the mufflerhas a lot of air resistance
High-performance exhaust systems useheaders, big tail pipes and free-flowingmufflers to eliminate back-pressure in theexhaust system
Lightweight parts help the engine performbetter
Fuel injection allows very precise metering offuel to each cylinder
improves performance and fuel economy