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Home , Combustion chamber, Connecting rod, Crankshaft, Crank (mechanism), Cylinder (engine), Cylinder (locomotive)

Internal T Alrayyes Internal Combustion Engine

Total Credits 3 credits Course Type Optional Name of Instructor Dr. Taleb BakrAlrayyes Email:[email protected] Text Book Pulkrabek, Willard W. Fundamentals of the Internal Combustion Engine , Prentice Hall Topics covered

• Operating characteristics • Engine Standard and real Cycles • Thermochemistry and fuel • and exhaust • Combustion • Emissions and air pollusion • Heat transfer in

Engine main strokes Early history • Huygens (1673) developed , Papin (1695) first to use steam in piston mechaanism • Lenoir Engine (1860): driving the piston by the expansion of burning products - first practical engine, 0.5 HP later 4.5 kW engines with mech efficiency up to 5%. several hundred of these engine • Otto-Langen Engine (1867), Mechanical Efficiency 11%. • Otto was given credit for the first built 4 internal combustion Engine • the internal combustion engine first appeared. • Also in this decade the two-stroke cycle engine became practical and was manufactured in large numbers. • 1892: noisy, large, single . • 1920s multicylinder engines where introduced • Daimler/Maybach (1882) Incorporated IC engine in automobile Single cylinder Otto Engine Engine parts

Valves: Minimum Two pre Cylinder

• Exhaust lets the exhaust gases escape the . (Diameter is smaller then Intake valve)

• Intake Valve lets the air or air fuel mixture to enter the combustion chamber. (Diameter is larger than the exhaust valve • Shaft: The shaft that has intake and Exhaust for operating the valves • Cam Lobe: Changes rotary motion into . • Valve Springs: Keeps the valves Closed. Different arrangements of valve and cam shaft

Valve damage • The valves can be damaged in two ways: • Bent Valves • The most common failure in valves • result of contact with the piston (The valves contacting the top of a piston is due to incorrect engine synchronization caused by timing chain/ breakage and incorrect fitting of new belts and chains.) • it is crucial not to attempt to start the engine as this may result in more costly damage being caused to the , and cylinder bores. • Burnt valve • Essentially this is caused by combustion gases escaping between the valve and valve seat when they are not sealing correctly. The hot combustion gases are forced past the valve which starts to burn away the edge of the valve • It is caused by • Excessive localized heat • Combustion gases escaping past the valve and concentrated at only one point • Irregular valve sealing with cylinder head valve seat. Carbon residues generated by irregular combustion (poor mixture) will appear at the seat region and will jeopardize the sealing between the valve and its seat Bent Valves Burnt Valves Spark plugs

It provides the means of ignition when the engine’s piston is at the end of compression stroke, close to Top Dead Center(TDC)

The difference between a "hot" and a "cold" is that the ceramic tip is longer on the hotter plug. Signs of faulty spark plug

• Engine has a rough idle • Having trouble starting your • Your engine misfires • High fuel consumption • Lack of acceleration

Foundation of the engine and contains pistons, shaft, cylinders, timing sprockets and sometimes the cam shaft. Engine crack Usually happened at area where there is thin casting It can start small then propagate as a result of thermal stress and strain cycles Cause of Engine crack

1. Engine full of water in very cold weather. The ice will crack the block. 2. Engine has inadequate oil when running. The heat can cause the block to crack. 3. Over heating, due to the lack of of failure of the cooling . Minor causes including 1. Bad in causes it to break. This can cause the block to break as the connecting rod goes through it. 2. Broken valve springs can drop a valve into the piston, causing the piston and/or connecting rod to crack the block. 3. Broken cam drive chain can cause the valves to be open at the wrong time and cause the pistons or con rods to break the block Piston

• A movable part fitted into a cylinder, which can receive and transmit power. Through connecting rod, forces the crank shaft to rotate. Causes of damages for Piston

• Un complete combustion, damage From Running Unmixed Fuel • Damage From Debris Getting Through the • Damage From Bearing Failure • Damage From Detonation, Knock Connecting (conn.) Rod • Attaches piston (wrist-pin) to the crank shaft (conn. Rod caps). is the main reason for the damage in the connecting rod • It happens when the volume of that’s entering the combustion chamber (water or fuel) exceeds the chamber’s volume. • Can happen if coolant leaked to the cylinder either due to engine head crack or driving through a deep water • Although it’s rare, sometimes a bad ECM/PCM or fuel can cause too much fuel to enter a cylinder, causing hydrolocking and resulting in a bent rod. Piston rings

• Four stroke: Three rings Top two are compression rings (sealing the compression pressure in the cylinder)and the third is an oil ring (scrapes excessive oil from the cylinder walls) • Two Stroke: Two Rings Both the rings are Compression rings. Common Symptoms of Damaged Piston Rings

The piston rings are damaged for the same reason as piston Common symptoms are • White or gray exhaust smoke • Excessive oil consumption • Low power for acceleration • Overall loss of power or poor performance Cylinder head

• Part that covers and encloses the Cylinder. • It contains cooling fins or water jackets and the valves. • Some engines contains the cam shaft in the cylinder head. Damage in the cylinder head

• The following symptom's could be due to either a crack in the cylinder head or failure in the head • Mix in oil and water

Crank shaft • Converts up and down or reciprocating motion into circular or rotary motion. Reason for failure or misalignmentvin Crank shaft • Fatigue failure • Insufficient : • Vibration (Loose engine foundation) • Over Pressurised Cylinder (Hydrolock) • Crack in the bearing saddle or Loose bolt leading to damage of main bearing • Very high bending moment on the due to excessive force from piston assembly

Starter pan, oil , and oil pump Water pump, radiator and Water circulation Engine Classification

1. Type of Ignition a) Spark Ignition Engine (SI Engines) • Mixture is uniform (conventional engines), mixture is non-uniform (stratified-charge engines) • Ignition is by the application of external energy (to spark plug) b) Compression Ignition (CI Engines). • By compression in conventional engine (Diesel engine), • Pilot injection of fuel in gas engines (eg, natural gas and diesel fuel – dual fuel engines) Engine Classification

2. By application • , scooters, 0.75 – 70 kW, SI, 2- and 4-stroke • passenger , 15 – 200 kW, SI and CI, 4-stroke • light commercial , 35 – 150 kW, SI and CI, 4-stroke • Heavy commercial vehicles, 120 – 400 kW, Diesel, 4 stroke • , 400 – 3 000 kW, CI, 4-stroke • ships, 3 500 – 22 000 kW, CI, 2- and 4-stroke • airplanes, 45 – 3 000 kW, SI, 4-stroke • stationary engines, 10 – 20 000 kW, CI, 2- and 4-stroke Engine Classification

3. Engine Cycle 3. Four-Stroke Cycle. • A four-stroke cycle experiences four piston movements over two engine revolution for each cycle. • complete cycle in 720 OCA • naturally aspirated, supercharged, turbocharged 4. Two-Stroke Cycle. • A two-stroke cycle has two piston movements over one revolution for each cycle. • complete cycle in 360 OCA • supercharged, turbocharged Engine Classification 4. Basic Design • Reciprocating. • Rotary . • (Felix Wankel, prototype in 1929, patented double rotor in 1934). • Engine is made of a block (stator) built around a large non-concentric rotor and crankshaft. The combustion chambers are built into the nonrotating block. Rotary Engines

http://www.animatedengines.com/wankel.html Engine classification

Mazda Rx-8 250 hp engine Triple rotor engine by Mazda Engine Classification 5. Position and Number of Cylinder: • Single cylinder • In-Line: The cylinders are arranged in a line, in a single bank. (2 to 11 cylinders, L4 and L6 are the most common ones • V-Engine: : The cylinders are arranged in two banks, set at an angle to one another. (2 to 20 cylinders more, V6, V8 and V12 are the most common ones) • Opposed Cylinder Engine (): The cylinders are arranged in two banks on opposite sides of the engine. Commonly used in small aircrafts and some automotive Engine classification

Opposed Cylinder Engine (flat engine): Engine Classification Engine Classification Engine classification Engine Classification

• : • Same as a except with three banks of cylinders on the same crankshaft. • Usually 12 cylinders with about a 60° angle between each bank.

• Opposed Piston Engine: • Two pistons in each cylinder with the combustion chamber in the centre between the pistons. • A single-combustion process causes two power strokes at the same time, with each piston being pushed away from the centre and delivering power to a separate crankshaft at each end of the cylinder. • Engine output is either on two rotating oron one crankshaft incorporating complex mechanical Engine Classification • • Engine with pistons positioned in a circular plane around the central crankshaft. • Always has an odd number of cylinders ranging from 3 to 13 or more. Operating on a four- stroke cycle, • every other cylinder fires and has a power stroke as the crankshaft rotates, giving a smooth operation. Many medium- and large-size -driven use radial engines. For large aircraft, two or more banks of cylinders are mounted together, one behind the other on a single crankshaft, making one powerful, smooth engine. Very large ship engines exist with up to 54 cylinders, six banks of 9 cylinders each. Engine Classification 6. Air Intake Process: • Naturally Aspirated. • Supercharged: Intake air pressure increased with the drivenoff of the engine crankshaft • Turbocharged : Intake air pressure increased with the turbine-compressor driven by the engine exhaust gases • Compressed: Two-stroke cycle engine which uses the crankcase as the intake air compressor. Limited development work has also been done on design and construction of four-stroke cycle engines with crankcase compression. with EGR system Engine Classification 7. Fuel used, • gasoline engines • diesel engines • natural gas (CNG and LNG), • methane, • LPG engines • alcohol engines • • Dual Fuel. Some, usually large, CI engines use a combination of methaneand diesel fuel. These are attractive in developing third-world countries because of the high cost of diesel fuel. Combined gasoline-alcohol fuels Engine Classification 8. Type of cooling, • Air Cooled. • Liquid Cooled, Water Cooled. Method of Fuel Input for SI Engines

• (a) Carbureted. • (b) Multipoint Port . One or more at each cylinder intake. • (c) Body Fuel Injection. Injectors upstream in intake manifold. ENGINE EMISSIONS AND AIR POLLUTION

• The exhaust of automobiles is one of the major contributors to the world's air pollution problem. • Recent research and development has made major reductions I engine emissions, but a growing population and a greater number of automobiles means that the problem will exist for many years to come. • During the first half of the 1900s, automobile emissions were not recognized as a problem, mainly due to the lower number of vehicles. As the number of automobiles grew along with more power plants, home furnaces, and population in general, air pollution became an ever-increasing problem. Main Pollutants

• Four major emissions produced by internal combustion engines are: • hydrocarbons (He), • carbon monoxide (CO), • oxides of nitrogen (NOx), • and solid particulates. Pollution reduction

• Two methods are being used to reduce harmful engine emissions: • One is t improve the of engines and fuels so that better combustion Occurs and fewer emissions are generated. • The second method is aftertreatment of the exhaust gases. This is done by using thermal converters or catalytic converters that promote hemical reactions in the exhaust flow. These chemical reactions convert the harmful emissions to acceptable CO2, H20, and N2

Laws and polution

• During the 1940s, the problem was first seen in the Los Angeles area due to the high density of people and automobiles, as well as unique weather conditions. By the 1970s, air pollution was recognized as a major problem in most cities of the United States as well as in many large urban areas around the world. Euro emissions regulation