Internal Combustion Engine Examples
- Gasoline (2 Stroke / 4 Stroke)
- Diesel (2 Stroke / 4 Stroke)
- Wankel Rotary
- Gas Turbine
What is Internal Combustion?
The generation of pressurized gas occurs inside the engine
External Combustion Engine Examples
- Steam Turbine
- Rankine Cycle
4 Stroke Cycle - Gasoline
- Intake
- Compression
- Power
- Exhaust
Intake Stroke - Gasoline
Mixture of fuel and air is sucked in through the intake port
Compression Stroke - Gasoline
Air-Fuel mixture is compressed and temperature of the mixture rises by several hundred degrees
Power Stroke - Gasoline
Compressed air-fuel mixture is ignited by the spark plug
Exhaust Stroke
spent fuel-air mixture goes out through the exhaust valves
TDC versus BDC position in 4 stroke
- Intake: TDC to BDC
- Compression: BDC to TDC
- Power: TDC to BDC
- Exhaust: BDC to TDC
When are valves open and closed during 4 stroke?
Open: Intake and Exhaust
Closed: Compression and Power
Arrangements of 4 Stroke Gasoline
- Inline
- Flat
- V
Advantages of 4 Stroke Engine gasoline
- Relatively efficient to external
- Relatively inexpensive to gas turbine
- Relatively easy to refuel to electric car
- Cleaner Emissions to 2 stroke
What is the entrance and exit sites in a 4 stroke gasoline engine?
Valves
What is the entrance and exit sites in a 2 stroke gasoline engine?
Ports
Advantages of 2 stroke engine gasoline
- no valves, simpler construction and lower weight
- fire once every rotation rather than every other
- can work in any orientation
Disadvantages of 2 stroke engine gasoline
- lack of lubrication system –> wear quickly
- doesn’t use fuel efficiently, less MPG
- increased pollution
What step is different is 4 stroke diesel compared to gasoline?
- Power Stroke
- fuel injector injects fuel into compressed air, which immediately ignites
Gasoline v Diesel - Intake
Gas - Intakes gas and air mixture
Diesel - Intakes Air, compresses it, then injects fuel
Gasoline v Diesel - Compression Ratio
Gas - 8:1 to 12:1
Diesel - 14:1 to 25:1
Gasoline vs Diesel - Carburetion
Gas - Mixes air and fuel outside of the cylinder (carburation or port fuel injection)
Diesel - direct fuel injection
