This document discusses various ways that internal combustion engine valves are cooled to withstand high temperatures, including air cooling, oil cooling, sodium filling, and valve seat inserts. It focuses on how sodium-cooled valves remain at low temperatures by using sodium's high thermal conductivity to rapidly absorb heat from hot gases and efficiently transfer it away from the valve head. The document also explains the function of hydraulic valve lifters in maintaining proper valve clearances and their self-adjusting operation using engine oil pressure to compensate for wear.

1. Internal Combustion Engine
PRESENTATION
Name No matrix
TANG KAI ZONG 01DAD21F1020
YEAP YIN HANG 01DAD21F1025
KOH YONG HONG 01DAD21F1029
MANVIR SINGH SANDHU A/L LAKBIR SINGH 01DAD21F1032

2. Sketch and label hot zones on an exhaust valve.

3. Ways to Cool Intake and Exhaust Valves
● Air Cooling: In most engines, valves are cooled by the flow of cool air around
them, facilitated by the cylinder head design and valve placement, as the
movement of the pistons and crankshaft generates airflow that dissipates heat
from the valves.
● Oil Cooling: Some engines cool the valves by circulating engine oil through
passages in the cylinder head, where it absorbs heat from the valves, and then
the heated oil is cooled in the engine's oil cooling system before being
recirculated, effectively controlling valve temperatures.
● Sodium Filling: High-performance engines, especially in racing or high-stress
applications, may fill the valves with sodium for its superior heat transfer
properties, where the hollow valves absorb heat, and the heated sodium transfers
it to the valve stem, facilitating effective heat dissipation through contact with the
cooler valve guide and cylinder head.
● Valve Seat Inserts: Valve seat inserts, typically made of heat-conductive
materials like bronze or beryllium copper, are placed around the valve seats in
the cylinder head, allowing the heat from the valves to be conducted into the
inserts, which then transfer and dissipate the heat to the surrounding cylinder
head.

4. How Sodium-Cooled Valves Remain at Low
Temperature
● Sodium-cooled valves use the properties of sodium to maintain lower
temperatures.
● Valve is hollow and filled with sodium.
● Sodium has excellent heat transfer capabilities.
● When the valve head comes into contact with hot gases, sodium rapidly
absorbs the heat.
● Sodium efficiently carries heat away from the valve head to the valve stem.
● Valve stem is in contact with the cooler valve guide and cylinder head.
● Heat is dissipated from the valve stem to the surrounding components.
● Sodium's high thermal conductivity enables effective heat transfer.
● Valve movement aids in circulating sodium for enhanced heat transfer.
● Sodium cooling prevents overheating, reduces wear, and enhances engine
performance and durability.

5. Function of Hydraulic Valve Lifter
• Hydraulic valve lifter is a crucial component in internal combustion engines.
• Its main function is to maintain proper valve clearances.
• Prevents excessive valve clearance, which can cause noise and poor engine
performance.
• Ensures consistent contact between the camshaft and the valve.
• Hydraulic valve lifter compensates for wear and expansion in the valve train components.
• It eliminates the need for periodic adjustment of valve clearances.:
• The lifter consists of a cylinder with a plunger.
• Engine oil pressure creates a hydraulic cushion within the lifter.
• As the camshaft rotates, it pushes against the plunger.
• The plunger, in turn, opens the valve, allowing proper airflow.
• The hydraulic cushion helps maintain constant contact between the camshaft and the
valve.
• It automatically adjusts to take up any slack or clearance changes.

6. THE CONSTRUCTION
OF HYDRAULIC VALVE
LIFTER

7. The operation of Hydraulic Valve Lifter
Hydraulic valve lifter is
a component in internal
combustion engines
that ensures proper
valve operation.
The lifter is positioned
between the camshaft
and the valve.
It consists of a cylinder
and a plunger inside.
Engine oil pressure is
used to operate the
lifter.
As the engine runs, oil
is pumped into the lifter.
The oil fills the cylinder,
creating a hydraulic
cushion.
The camshaft pushes
against the plunger of
the lifter.
The plunger, under the
force of the camshaft,
opens the valve.
The hydraulic cushion
ensures constant
contact between the
camshaft and the valve.
If there is excessive
valve clearance, the
lifter automatically
adjusts to compensate
for it.
The self-adjusting
nature of the lifter helps
maintain proper valve
clearances.
This operation ensures
efficient airflow and
combustion in the
engine.

8. THANK YOU