Objectives: ➢Identify and Explain the Engine Components; ➢Classify the two types of Engine Cycle Operation; ➢Value the importance of Engine Operation. What is Engine? ➢A machine that converts electrical and chemical energy into mechanical energy thru internal combustion. What part of Automotive Engine is shown? A. Cylinder Head B. Engine Block C. Piston Assembly Components of Engine Engine/ Cylinder Block – is the main structural component of an engine. It supports and helps maintain alignment of internal and external components. The cylinder block is the engine component that consists of the cylinder bore, cooling fins on air cooled engines, valve train components, depending on the engine design. What is the correct term that describe the image given? A. Cylinder Head B. Engine Block C. Piston Assembly Components of Engine Cylinder Head – is a cast aluminum alloy or cast iron engine component fastened to the end of the cylinder block farthest from the crankshaft. A head gasket is the filler material placed between the cylinder block and cylinder head to seal the combustion chamber. Head gaskets are made from soft metals and graphite layered together. What part of Automotive Engine is shown? A. Cylinder Head B. Engine Block C. Crankshaft Components of Engine Crankshaft – is an engine component that converts the linear (reciprocating) motion of the piston into rotary motion. The crankshaft is the main rotating component of an engine and its commonly made of ductile iron. Features of crankshaft include the crankpin journal, throw, bearing journals and counterweights What part of Automotive Engine is shown? A. Cylinder Head B. Crankshaft C. Piston Assembly Components of Engine Piston and piston rings – a piston is a cylindrical engine component that slides back and forth in the cylinder bore by forces produced during the combustion process. The piston acts as a movable end of the combustion chamber. Pistons are commonly made of a cast aluminum alloy for excellent and lightweight thermal conductivity. Components of Engine Connecting rod – is an engine component that transfers motion from the piston to the crankshaft and functions as a lever arm. Connecting rods are commonly made from cast aluminum alloy and are designed to withstand dynamic stresses from combustion and piston movement What part of Automotive Engine is shown? A. Bearings B. Crankshaft C. Piston Assembly Components of Engine Bearings – a bearing is a component used to reduce friction and to maintain clearance between stationary and rotating components of the engine. Bearings, or bearing surfaces are located on the crankshaft, connecting rod, and camshaft and also in the cylinder block. What part of Automotive Engine is shown? A. Cylinder Head B. Flywheel C. Piston Assembly Components of Engine Flywheel - is a cast iron, aluminum, or zinc disk that is mounted at one end of the crankshaft to provide inertia for the engine. Inertia is not a force, it is a property of matter. During the operation of a reciprocating engine, combustion occurs at distinct intervals. The flywheel supplies the inertia required to prevent loss of engine speed and possible stoppage of crankshaft rotation between combustion intervals. What part of Automotive Engine is shown? A. Cylinder Head B. Piston Assembly C. Valve Valves – allow the flow of air-fuel mixture into the cylinder, and the flow of exhaust gases from the cylinder. Intake Valve ➢A types of Valve that allows Air & Fuel Mixture to enter the combustion chamber Exhaust Valve ➢A types of valve that allow the burned gasses to go outside the combustion chamber Components of Engine Valve Train – the valve train of internal combustion engine includes components required to control the flow of gases into and out of the combustion chamber. This includes valves and related components required to allow the air fuel mixture to enter the combustion chamber, seal the combustion chamber during compression and combustion, and evacuate exhaust gases when combustion is complete. Engine Cycle Operation What is Cycle? Cycle ➢It is an event happen repeat themselves ➢In an internal combustion engine there are several cycle happen and these are: ➢Intake stroke ➢Compression stroke ➢Power stroke ➢Exhaust stroke What is stroke? ➢It is a piston movement form TDC to BDC ➢TDC- Top Dead Center ➢BDC- Bottom Dead Center Two Types of Engine Cycle Operations: 4-Stroke Cycle Engine Operation ADVANTAGES 1.More torque :- In general, 4 stroke engines always make extra torque than 2 stroke engine at low RPM. Although 2 stroked ones give higher torque at higher RPM but it has a lot to do with fuel efficiency. 2.More fuel efficiency :- 4 stroke engines have greater fuel efficiency than 2 stroke ones because fuel is consumed once every 4 strokes. 3.Less pollution :- As power is generated once every 4 strokes & also as no oil or lubricant is added to the fuel; 4 stroke engine produces less pollution. 4.More durability :- We all know that more the engine runs, quicker it wears out. 2 stroke engines are designed for high RPM. If an engine can go for 10000 rpm’s before it wears out; a 4 stroke engine with 100 rpm will run for 100 minutes than the other 2 stroke engine which has a higher rpm of 500 & will run for only 20 minutes. 5.No extra addition of oil :- Only the moving parts need lubrication intermediately. No extra oil or lubricant is added to fuel. DISADVANTAGES 1.Complicated design :- A 4 stroke engine has complex valve mechanisms operated & controlled by gears & chain. Also there are many parts to worry about which makes it harder to troubleshoot. 2.Less powerful :- As power gets delivered once every 2 rotations of crankshaft(4 strokes), hence 4 stroke is less powerful. 3.Expensive :- A four stroke engine has much more parts than 2 stroke engine. So they often require repairs which leads to greater expense. 2-Stroke Cycle Engine Operation ADVANTAGES 1.Simple design & construction :- It doesn’t have valves. It simply has inlet & outlet ports which makes it simpler. 2.More powerful :- In 2 stroke engine, every alternate stroke is power stroke unlike 4 stroked one in which power gets delivered once every 4 strokes. This gives a significant power boost. Also, the acceleration will be higher & power delivery will be uniform due to same reason. 3.Position doesn’t matter :- 2 stroke engine can work in any position as lubrication is done through the means of fuel (as the fuel passes by through whole cylinder & crankcase). DISADVANTAGES 1.Less fuel efficiency :- For every alternate power stroke, fuel gets consumed every alternate stroke. This makes the engine less fuel efficient although it results in uniform power delivery. 2.Oil addition could be expensive :- Two-stroke engines require a mix of oil in with the air-fuel mixture to lubricate the crankshaft, connecting rod and cylinder walls. These oils may empty your pockets. 3.More pollution :- 2 stroke engine produces a lot of pollution. The combustion of oil added in the mixture creates a lot of smoke which leads to air pollution. 4.Wastage of fuel :- Sometimes the fresh charge which is going to undergo combustion gets out along with the exhaust gases. This leads to wastage of fuel & also power delivery of the engine gets effected. 5.Improper combustion :- The exhaust gases often get trapped inside the combustion chamber. This makes the fresh charge impure. Therefore maximum power doesn’t get delivered because of improper incomplete combustion. 2-Stroke Cycle Engine Operation What have you observed? Intake Stroke ➢A stroke where the Air & Fuel Mixture enter the combustion chamber, at this stroke the movement of piston is downward to create a certain vacuum. And the intake valve are open. Compression Stroke ➢A process where the Air and Fuel Mixture is being compressed into smaller space, at this point the movement of piston if upward. And both valves are closed. Power Stroke ➢A stroke where the compressed air & fuel mixture are burned with the used of spark plug, and the movement of piston are downward. This is the start of the second revolution of the cycle Exhaust Stroke ➢A stroke where the piston once again returns to top dead centre while the exhaust valve is open. Assignment Running Mate Firing Order Valve Over-Lap Piston no. 1 Piston no. 2 Piston no. 3 Piston no. 4 Intake Compression Exhaust Power Compression Power Intake Exhaust Power Exhaust Compression Intake Exhaust Intake Power Compression PISTON NO. 1 PISTON NO. 2 POWER PISTON NO. 3 PISTON NO. 4 PISTON NO. 1 PISTON NO. 2 PISTON NO. 3 INTAKE PISTON NO. 4 Quiz 1.1 1. A machine that converts electrical and chemical energy into mechanical energy thru internal combustion. 2. It is an event happen repeat themselves 3. It is a piston movement form TDC to BDC 4. A stroke where the piston once again returns to top dead centre while the exhaust valve is open. 5. A stroke where the compressed air & fuel mixture are burned with the used of spark plug, and the movement of piston are downward. This is the start of the second revolution of the cycle 6. A stroke where the Air & Fuel Mixture enter the combustion chamber, at this stroke the movement of piston is downward to create a certain vacuum. And the intake valve are open. 7. A process where the Air and Fuel Mixture is being compressed into smaller space, at this point the movement of piston if upward. And both valves are closed. 8. A types of Valve that allows Air & Fuel Mixture to enter the combustion chamber. 9. A types of valve that allow the burned gasses to go outside the combustion chamber 10. What is TDC?
