Automotive Internal Combustion Engine Classifications

1
Automotive Internal Combustion Engine
Classifications

• Engine Design
• Cylinder Arrangement
• Camshaft Location and Number
• Ignition Systems
• Combustion Chamber Designs

2
Engine Design

• Reciprocating (piston)
• 4 stroke cycle
• 2 stroke cycle (not currently used in automotive
  applications)
• Miller cycle differs from traditional 4 stroke
  by keeping intake valve open much longer
• Rotary

3
Cylinder Arrangement

• Inline
• 3/4/5/6 cylinder configurations
• V-type
• 6/8/10 cylinder configurations
• Horizontally Opposed
• 4/6 cylinder configurations

4
Cylinder Arrangement

• Firing Order sequence in which cylinders fire
• Cylinders are numbered from front to rear
• Determined by number of cylinders and arrangement
  of crankshaft throws

5
Camshaft Location and Number

• Overhead Cam (OHC) cam located in cylinder head
• SOHC one cam for both intake and exhaust valves
• DOHC separate intake and exhaust cams
• Pushrod cam located in engine block

6
Ignition Systems

• Method for igniting air/fuel mixture
• Spark Ignition (SI)
• Gasoline
• LNG
• CNG
• Alternative fuels
• Compression Ignition (CI)
• Diesel

7
Combustion Chamber Designs

• Wedge
• Intake and exhaust valves set in a plane
• Spark plug located above or below valve plane
• Cheaper manufacturing cost
• Hemispherical (hemi)
• Valves set in two planes
• Spark plug located between valves
• More efficient
• Higher output
• Higher manufacturing cost

8
Combustion Chamber Designs

• Non-interference (freewheeling)
• Clearance between open valves and piston at TDC
• Interference
• No clearance between open valves and piston at
  TDC
• Major engine damage if cam or crank is turned
  independently