Diesel Engine Cylinder Head-A Complete Overview




Cylinder head installed between cylinder liners and rocker arm cover. It connects intake and exhaust manifold, through expansion bellows. The components of cylinder head are Intake and Exhaust valves, Fuel injector, Safety valves, starting air valve etc. Cylinder head also facilitates completing different systems of power plant.

Different components Installed in cylinder head
  • Intake valve: Admits charge air into the combustion chamber
  • Exhaust valve: Evacuate exhaust gas from the combustion chamber
  • Fuel injector: Inject the fuel into the combustion chamber
  • Safety valve: Relief excess combustion pressure
  • Starting air valve: Admits starting air into the combustion chamber during starting
  • Different studs: Helps to secure different components
  • Indicator cock: Indicator cock installed to take peak /firing pressure
  • Sensor: Exhaust gas sensor installed to measure exhaust gas temperature
Diesel Engine Cylinder head components-MAN B&W Engine
Diesel Engine Cylinder head components-MAN B&W Engine
Different Systems Connected With Cylinder Head
  • Fuel System: Fuel oil through fuel injection valve injected into the combustion chamber.
  • HT Cooling Water System: To cool down cylinder head, Exhaust valve seat ring
  • Nozzle cooling Water: To cool down fuel injection nozzle.
  • Lubrication Oil System: To lubricate rotocap bearing or axial thrust bearing.
  • Starting Air System: Starting air and pilot airline connected with cylinder head.
  • Intake air system: Charge air from the charge air manifold admits into the combustion chamber through the cylinder head.
  • Exhaust Gas System: Exhaust gas due to combustion of fuel evacuates from combustion chamber to exhaust gas manifold through the cylinder head.
Cylinder head components MAN B&W Engine
Cylinder head components MAN B&W Engine
Material used in the cylinder head



Most common materials used to cast (generally casting process used) cylinder head is cast iron. Cast iron heads are inexpensive, durable, but weight is heavy. Aluminum also used to cast cylinder head. Aluminum heads are light weighted (about 50% of cast iron head), maintenance is easy, but the cost is higher and needs very careful attention during tightening studs and bolts (to avoid damage).

Different problems of cylinder head

Cylinder head acts as top cover of the combustion chamber of an inter combustion engine. It experience high temperature, pressure and corrosion. Most common problems arise with cylinder head are given below

  • Cylinder head crack
  • Inlet and Exhaust valve seat burnt
  • Inlet and exhaust valve burnt
  • Sticky valves
  • Hot and Cold Corrosion
  • Damaged sealing surface
  • Carbon deposit formation

Leave a Reply

Your email address will not be published. Required fields are marked *