Four stroke, two stroke, diesel, wankel lesson

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Start...
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Four Stroke, Two StrokeDiesel, Wankel Engine
Theory and Operation
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Four Stroke, Two Stroke,Diesel, Wankel
TheoryPresentation Outline

• 1.0 Four Stroke Engine Theory
• Internal combustion principles
• Valve operation
• Four cycles
• Valve timing
• 2.0 Two Stroke Engine Theory
• Two cycle operation
• Lubrication
• Variations
• Advantages/ limitations

more...
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• 3.0 Diesel Engine Theory
• Operation
• Variations
• Advantages/limitations
• 4.0 Wankel Engine Theory
• Operation
• Variations
• Advantages/limitations

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1.0 Four Stroke Engine Theory

• Intake
• Compression
• Power
• Exhaust

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Intake Stroke
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Compression Stroke
Valves closed
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Power Stroke
Valves closed
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Exhaust StrokValve Timing Diagram
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2.0 Two Stroke Engine Theory

• Up stroke
• Down stroke

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2 Stroke Up Stroke
Compression occurs
Transfer Port
Crank Case
Reed Valve
Carburetor
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2 Stroke Down Stroke
Intake Power Exhaust Occurs
Transfer Port

Reed Valve
Carburetor
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Fuel Mix

• Uses a premix of gas and oil
• Oil injectors used in some
• Normal mixes range from 161 to 501
• Typical hot engines 161
• Typical cool engine 501
• CHECK OWNERS MANUAL !!!

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Advantage of Two Strokes

• Runs in any position
• More horsepower for size
• Fewer moving parts
• Lighter

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Limitations of Two Strokes

• Uses more fuel than four strokes
• Fuel and oil must be mixed
• Plugs foul easily
• Poor emissions

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3.0 Diesel Engine Theory
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Introduction

• Invented by Rudolf Diesel between 1892 and 1893
• Internal Combustion Engine
• Reciprocating Engine
• Intermittent Combustion Engine
• Utilizes liquid fuel
• Compression Ignition vs. Spark Ignition
• Heavy Duty Applications

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Diesel Compression Ratio

• 201 up to 251 common
• Needed to ignite fuel
• No spark plugs

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Compression Ratios

• Squeeze on air/fuel mixture before combustion
• Efficiency increases with higher CR
• About 91 on gas autos
• 171 to 241 for diesel engines
• About 241 CR max
• too high compression for starting
• limiting strength of materials
• power loss- leakage around valves

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Advantages of the Diesel Engine

• High reliability
• Low fuel cost
• High power / lb. of engine
• Low fuel consumption
• Low fire hazard
• High torque at low RPM
• Greater heat efficiency- 30 (25 gas)
• Longer service intervals

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Disadvantages of Diesel Power

• Expensive to repair
• Hard starting in cold weather
• Higher initial cost

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Gasoline and Diesel Engine Comparison

• Gasoline power stroke 460 psi Diesel 1200psi
• Diesel heat efficiency about 5 higher than
  gasoline

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Induction System
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Glow Plugs

• Resistance unit to heat cold engines
• Installed in cylinder head, sometimes in special
  pre-combustion chamber
• Some use intake heaters
• In addition, block heaters for cold weather

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Typical Diesel Engine
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4.0 Wankel Engine Theory
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History of RCE(Rotary Combustion Engines)

• 1924 - Wankels idea for RCE
• 1933 - patent was applied
• 1936 - patent received
• 1957 - engine runs

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Epitrochoidal Bore
Apex Seal
Intake Port
Rotor
Spark Plugs
Exhaust Port
One of Three Chambers
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Rotor and Apex Seals

• Sometimes called a Rotary Piston
• Receives power impulse from fuel air mixture
• Rotor has three faces
• Apex seals at tips-like rings

Apex Seal Location
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Epitrochoidal BoreE-Bore

• Same purpose as the cylinder walls of the piston
  engine
• Epitrochoid curve, generated by rolling a circle
  around another circle

Basic shape of epitrochoid curve
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Rotors
Eccentric Shaft
E-Bore
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How a RCE Works

• Fuel air mix admitted into the peripheral housing
  through the intake port
• Ignition of the fuel air mix begins rotation of
  rotor through epitrochoid curve
• One face of rotor is compressing fuel air mix,
  another face is receiving mix

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How a RCE Works

• Otto cycle engine
• Intake, compression, power, and exhaust happen in
  three chambers of epitrochoid curve
• Rotor and eccentric shaft continuously rotate in
  same singular motion
• Gases exhausted through exhaust port

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Two Types of RCE

• KKM
• Kreiskolbenmotor or planetary rotation motor
• One statonary peripheral housing
• Rotor moves in orbit and propels eccentric shaft
• Most modern rotary engine

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Two Types of RCE

• DKM
• Drehkolben Maschine
• First RCE
• Inner rotating housing and rotor moving around a
  fixed shaft
• Disassemble engine to change spark plugs
• Achieves speeds of 25,000 rpm

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Advantages and Limitations

• Fewer moving parts
• Single motion allows smoother running
• Compact engine, allows for more space
• Few manufacturers produce this engine any longer

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Summary

• Name the four cycles of a four stroke
• Intake
• Compression
• Power
• Exhaust

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Summery (Cont)

• What are the major differences in parts between a
  2 stroke 4 stroke?
• Ports vs. Valves
• Reed valve vs. Valves
• How is the fuel ignited in a deisel engine?
• Compression

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Summery (Cont)

• The Rotory (Wankel) engine uses what type of
  bore?
• E- Bore
• What act like rings in a rotory engine?
• Apex seals
• Air can be __________, while water can not?
• Compressed

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The End