Cylinder heads function as the brain 🧠 of the engine—sitting on top of the engine block, they control how air, fuel, and exhaust gases move in and out of the combustion chamber. Without them, pistons would just pump up and down with nowhere for air to flow or power to escape.
🔍 What Cylinder Heads Do
- Seal the top of the cylinders with the help of a head gasket.
- Hold valves (intake & exhaust) that control airflow.
- Contain passages for coolant and oil to keep the engine cool and lubricated.
- House spark plugs (in gasoline engines) or injectors (in diesels).
- Work with the camshaft(s) to time valve opening and closing.
⚙️ Main Components
- Combustion Chambers – where the fuel-air mix ignites.
- Intake Valves – let air-fuel mixture into the chamber.
- Exhaust Valves – let burnt gases out.
- Valve Springs & Retainers – keep valves in place and ensure proper closing.
- Camshaft(s) – sometimes built into the head (OHC/DOHC engines).
- Coolant & Oil Passages – internal channels for temperature control and lubrication.
🛠️ Types of Cylinder Heads
- Flathead (side-valve) – old design, simple but less efficient.
- Overhead Valve (OHV / Pushrod) – valves in the head, camshaft in the block.
- Overhead Cam (OHC/DOHC) – camshaft(s) in the head, better performance and efficiency.
⚠️ Common Problems
- Warping or cracking (from overheating).
- Blown head gasket (leads to coolant-oil mixing, white smoke, overheating).
- Valve wear (causing loss of compression or rough running).
- Carbon build-up (reduces airflow efficiency).
