Piston Engine

RECIPROCATING ENGINE

•DESIGN AND CONSTRUCTION *  Type of Reciprocating Engine–Radial Engine–In Line Engine–V-Type Engine–Opposed Engine •REC. ENGINE REQUIREMENT •Reliability  à  Handal; bisa terbang selama 33 jam dari New York ke Paris th 1927.•Durability  à  The Curtis OX-5 pd era W.W I … TBO hanya 100 jam, modrn engine diharapkan bisa sampai 2000 jam TBO-nya •Operating Flexibility  à  Dapat run smoothly dan  dpat memberikan desire performance pd semua kecepatan dari idle sampai full power. • •Specipic Weight  à  The ratio of the weight of  an aircraft engine to the brake horsepower.   Engine used in the Wright Flyer … 14 pound per horsepower ;  FAA certificated horizontal opposed engine under two pounds per horsepower.•Streamlineability  à  Successful approaches to reducing the drag.•TYPE OF RECIPROCATING ENGINE • • *  Engine Components–Crankcase–Crank shaft–Connecting Rod–Piston–Cylinder–Valve •ENGINE COMPONENT •CRANKCASE OPPOSED ENGINE •CRANKCASE RADIAL ENGINE •CRANKSHAFT •Crankshaft à  Merupakan tulang punggung dr reciprocating engine dg tugas utama merubah gerakan bolak-balik dr piston dn connecting rod menjadi gerakan berputar utk memutar propeller.•Karena crankshat hrs menahan stress yg besar biasanya dibuat dr bhn campuran yg kuat spt chromium  - nickel molybdenum steel.•Bagian -bagian dr Crankshaft à  Main bearing journal, crankpin dn crank cheek.  Sbg tambahan ada  counterweights dn dampers utk me-reduce vibration • •Bearings  à  Adalah setiap bhn/barang yg mendukung dn me-reduce  friction dr dua barang yg bergerak.• •Macam2 bearing   :  -   Plain bearing  -   Ball bearing  -   Roller bearing •CONNECTING RODS •Connecting Rods  à  Adalah sambungan yg melanjutkan gaya/tenaga yg dihasilkan piston ke crankshat.•Type of connecting rod  :  -  Plain type  -  Master and articulated rod type  -  Fork and blade type •PISTON •Piston head•Piston skirt•Piston pin boss•Piston pin•Ring groves •PISTON •CYLINDER •Choke bore cyl. à Diameter  top cyl < Diameter skirt cyl.•Cyl. Hardened à  -  Nitriding        -  Crome platingNitrided Cyl.  à  Warna biru àCyl. Base / FinChrome plated à  Warna Orange à Cyl base / Fin                 
•CYLINDER & CYLINDER NUMBERING •RAD. CYL. NUMBERING & VALVE •BASIC VALVES COMPONENT •Valves head•Valve face
•Valve neck•Valve stem•Valve tip• •Some Valves are filled with metallic sodiumto reduce their operating temperatures. •VALVE SEAT & VALVE OPR. MECHANISM •CAM RING SPEED & RAD.ENG. VALVE MECHANISM •PROPELLER REDUCTION GEARS •Permits a Propeller to turn slower than the engine•Reduction gear sys. Utilize spur gears, planetary gears or combination of two•A quill shaft à  Hardened steel shaft  dipasang antara prop shaft dan crank shaft utk meredam torsional vibration.•Gear Ratio =  Teeth Ring gear+Teeth Sun gear
             Teeth  Ring Gear•PROPELLER SHAFTS •Tapered propeller  shaft•Splined propeller shaft•Flanged propeller shaft•Tapered shaft -à  Used on low power engine•Splined shaft   à  Used on high power radial engine•Flanged shaft à  Modern hor. Opposed engine •ENGINE IDENTIFICATION •O - Horizontally opposed engine•R - Radial engine•I - In-Line engine•V - V- type engine•T - Turbocharged•I - Fuel Injected
•S - Supercharged•G - Geared nose section (prop reduction gear) • •L- Left hand rotation (for multi engine install)•H - Horizontal mounting (for helicopters)•V - Vertical mounting (for helicopter)•A- Modified for aerobatic •*  OPERATING PRINCIPLE   =  Energy Transformation  =  Energy Transformation Cycles    -  Four Stroke Cycle      +  Intake Stroke    +  Compression Stroke      +  Exhaust Stroke    +  Valve Timing    +  Firing Order  =  Two Stroke Cycle•ENERGY TRANSFORMATION •Chemical energy  fuel à Heat energy à Tekanan gas meningkat  dlm Cyl  à Mechanical energy  krn gerakan piston “down ward”•Karena fuel yg digunakan menghasilkan panas yg dibakar dlm cylinder maka aircraft engine  termasuk  “internal combustion engine” •ONE STROKE & 4 STROKES CYCLE •VALVE TIMING •FIRING ORDER •TWO STROKE CYCLE • =  Work - Power Consideration   -  Work     Work (W) = Force (F) x Distance (D)   -  Power
    Power  =  Force x Distance
                           Time 
  -  Horsepower    Horsepower  =  Force x Distance                              33.000 X Time • -INDICATED HORSEPOWER                                             PLANK  Indicated Horsepower = ---------------                                              33.000  P = Indicator Mean Effective Pressure (IMEP) inside the  
            cylinder during power stroke.  L  = Length of the stroke in feet or fraction of a  foot.  A  = Area of the piston head in square inches.N = Number of power strokes per minute for one cylinder, Or a four stroke engine, this is found by dividing the Rpm by two.K  = The Number of Cylinder or the engine • -Brake Horsepower                                      2π    x Torque x Rpm  Brake Horsepower  = --------------------------                                            33.000-Piston Displacement  Total Piston Displacement = A X L X N  A  =  Area of piston head in square inches  L  =  Length of the stroke in inches  N  =  Number of Cylinder• FACTORS AFFECTING POWER- -Manifold pressure-Detonation and Preignition -Compression Ratio-Ignition Timing • •Man Pressure à Absolute pressure of the fuel/air mixture at apoint just outside a cylinder intake port.•Detonation à Uncontrolled explosive ignition of the fuel/air mixture in the cylinder.•Preignition à The fuel/air mixture ignites too soon, it is caused by hot spots in cylinder that ignite the fuel/air mixture before the spark plug fire. • •Compression Ratio à The ratio of cylinder volume with the piston at the bottom of its stroke to the volume with the piston at the top of its stroke.•Ignition Timing à  When the ignition event is properly timed, complete combustion and maximum pressure occur  just after the piston passes top dead center at the beginning of the power stroke. • •Penyebab detonation  :  a.  Lower fuel grade  b.  Wrong ignition timing  c.  Heavy engine load at low Rpm  d.  Fuel/Air mixture too lean  e.  High Compression ratio• •Akibat dari Detonation :  a.  High  cyl temp & pressure  b.  Rough engine running  c.  Overheating  d.  Power loss •   Bentuk Hot Spot  :   a.  Adanya Carbon Particle  b.  Overheated valve edges  c.  Silica deposits on spark plug electr.
  Penyebab  Hot Spot  a.  Poor engine cooling  b.  Dirty intake air filters  c.  Shutting down engine at high rpm •DETONATION •COMPRESSION RATIO •DISTRIBUTION OF POWER –EXHAUST  à  45  %–FRICTION  à  5    %–COOLING  à  20  %–PROPELLER LOSSES  à  3    %–USEFUL WORK  à  27  % •RECIPROCATING ENGINE FUEL METERING =   Type of Metering Devices=   Metering Principles=   Fuel / Air Chemistry     -   Atmosphere Contens      -   Fuel / Air Ratio=   Mixture Ratio Terminology=   Leaning Techniques=   Specipic Fuel Consumption• •FUEL METERING à  Fuel metering adalah bagian dari fuel system utk mengontrol jumlah fuel yg dikirim ke engine.   Utk mendapatkan best engine performance dan fuel economy, fuel metering  hrs mampu mencampur fuel dan udara yg tepat dihadapkan dg pengopera-sian yg luas dan kondisi lingkungan.•Fuel metering jg hrs mampu mengatomisasi dan  mendistribusikannya sehingga dpt dibakar dg sempurna dalam cylinder. •TYPE OF METERING DEVICES •Carburator •Fuel Injection Unit• •Carburator à  a.  Float type carburator    b.  Pressure Injection Carb. •METERING PRINCIPLES •MIXTURE RATIO TERMINOLOGY •Rich indicates that air has been removed or fuel has been added to a given mixture.• •In other words, a mixture ratio of 8 : 1 is richer than a mixture ratio of 10  :  1. • =   Detonation and Preignition =   Backfire and Afterfire =   Carburetor=   Carburetor Venturi Principles=   Carburetor System=   Float Type Carburetor     -   Main Metering     -   Air Bleed=   Float Type Carburetor Maintenance • •BACKFIRE à  Apabia fuel/air mixture too lean,  terjadi penyalaan sebelum intake valve close, di induction manifold, fuel metering unit dan diluar induction air filter.   Backfire selalu terjadi dalam induction system.• •AFTERFIRE à  Apabila fuel/air mixture exce-ssively rich , pembakaran didalam cylinder blm sempurna sebelum exhaust valve open, pem-bakaran berlanjut dalam exhaust system, dlm hal ini biasanya timbul nyala api keluar dari ex-haust pipe. • •CARBURATOR  à  Mix fuel and air to establish an optimum fuel /air ratio.•In addition  à  Semua Carburator membuat atomisasi fuel dan menghasilkan campuran fuel dan udara kemudian mendistribusikannya semerata mungkin kepada setiap cylinder.•All carburators are equipped with a throttle valve, the throttle valve sometimes referred to as a butterfly valve, consist of a flat, circular piece of metal that is always installed between venturi and the engine. •CARBURATOR VENTURI PRINCIPLES •CARBURATOR SYSTEM •Carburator sys  à  Diberikan utk supaya engine beroperasi dg baik dibawah engine loads, speeds and air densities yg bervariasi.•Carburator system antara lain terdiri dari  :  -  Main metering  -  Idling  -  Mixture control  -  Accelerating  -  Power enrichment or economizer • •Two type Carburetor yg akan kita diskusikan  :  -  Float type Carburator   -  The Pressure Injection Carburetor
Float type  à  Menggunakan float utk mengatur sejumlah fuel yg masuk ke dlm Carburetor, dlm float type carb. Fuel disimpan dlm float chamber.  Sejumlah fuel yg masuk ke dlm float chamber diatur oleh needle valve. •FLOAT TYPE CARB. & MAIN METERING •MAIN METERING •Guna Main Metering à  Utk men-supply sejumlah fuel yang tepat ke dlm engine utk semua kecepatan diatas idle.•Main metering system terdiri dari  :•One or more venturi tube•Main metering jet•Discharge nozzle•Throttle valve• •FUEL METERING HEAD  à Beda permukaan fuel di float chamber dan dischard nozzle – 1/8  inch•KEGUNAAN à Untuk mencegah tumpahan fuel dari Nozzle ketika engine shut down• •SURFACE TENSION à Secara pisik milik fluida, merupakan daya menyatu dari molekul-mole-kul, dg adanya cohesiveness fluida bertendensi menyatu dp menyebar/pecah. •DISCHARGE NOZZLE •AIR BLEED •IDLING SYSTEM •IDLING SYSTEM •IDLING SYSTEM • •AS GENERAL RULE  à  MIXTURE YG DIBE-RIKAN OLEH IDLING SYSTEM  ADALAH KAYA JIKA DIBANDINGKAN DG MAIN METERING SYSTEM, HAL INI DIPERLUKAN UNTUK ENGINE COOLING KRN ALIRAN UDARA PD SAAT IDLING TDK CUKUP EFEKTIF UTK  PENDINGINAN.•MIXTURE CONTROL  à  REGULATE THE RATIO OF FUEL AND AIR SUPPLIED TO THE ENGINE, TO ALLOW  THE ENGINE TO OPERATE EFFICIENTLY AT VARIOUS ALTITUDES  AND VARIETY OF CONDITIONS.. • •MIXTURE CONTROL  :  1.  VARIABLE ORIFICE MIX. CONTROL  2.  BACK SUCTION MIX. CONTOL.*  VARIABLE O.M.C.  à  POSISI IDLE CUT OFF NO FUEL FLOW TO THE MAIN METERING JET.  WHEN VALVE FULLY OPEN THE AMOUNT OF FUEL ALLOWED TO FLOW TO THE DISCHARGE NOZZLE  IS RESTRICTED ONLY BY  THE MAIN METERING.   WHEN PLACE IN AN INTERME-DIATE POSITION à  FUEL FLOW TO DISCHARGE NOZZLE DETERMINE BY SIDE OF OPENING IN MIXTURE VALVE. •VARIABLE ORIFICE MIX. CONTROL • •BACK SUCTION MIX. CONTROL.  à  LOW PRESSURE IS USED TO CONTROL THE PRESSURE DIFFERENTIAL BETWEEN THE VENTURI AND FLOAT CHAMBER, LOW PRESSURE IS TAKEN FROM VENTURI AND ROUTED THROUGH A MIXTURE CONTROL VENT VALVE INTO THE FLOAT CHAMBER.•CARBURATOR USE BACK SUCTION MIX. CONT. THE FLOAT CHAMBER IS VENTED TO THE ATMOSPHERE AND TO A LOW PRESSURE NEAR THE VENTURI •BACK SUCTION MIX. CONTROL • •AUTOMATIC MIXTURE CONTROL  à  A FEW FLOAT TYPE CARBURETOR UTILIZE A MIXTURE CONTROL SYSTEM THAT AUTOMATICALLY MAINTAINS THE PROPER FUEL/AIR MIXTURE DURING FLIGHT.•ACCELERATION SYSTEM  à  PROVIDES AN IMMEDIATE, BUT BRIEF, INCREASE IN FUEL FLOW IN THE THROAT OF CARBURETOR TO ENRICHEN THE MIXTURE •ACCELERATION SYSTEM •ACCELERATION WELL•ACCELERATION PUMP SYSTEM• •Acceleration Well  à  When the throttle is rapidly advance, the excess fuel in the accele-ration well is drawn out through the discharge nozzle so ample fuel is available to produce a rich mixture. • •Accelerator Pump  à  When the throttle valve is opened quickly, the piston moves down and forces the stored fuel past a discharge check valve and through a separate discharge nozzle into airstream. •ACCELERATION WELL •ACCELERATOR PUMP • •POWER ENRICHMENT/ECONOMIZER SYSTEM  à  ONE WAY OF DISSIPATING  EXCESS HEAT IS TO INCORPORATE A POWER ENRICHMENT SYSTEM THAT PROVIDES  A RICH FUEL/AIR MIXTURE AT HIGH POWER SETTINGS.   THIS WAY THE EXCESS FUEL IN THE MIXTURE HELP COOL YHE CYLINDERS.
•ALTHOUGH POWER ENRICHMENT  SYTSEM INCREASES FUEL FLOW AT HIGH POWER SETTING IT DOES PERMIT AN OPERATOR  TO USE A LEANER MIXTURE  DURING NORMAL CRUISE OPERATIONS.   FOR THIS REASON A POWER ENRICHMENT SYSTEM IS SOMETIMES REFERED TO AS AN ECONOMIZER SYSTEM.• •POWER ENRICHMENT/ECONOMIZER SYSTEM :
  a.  NEEDLE TYPE  b.  AIR BLEED TYPE•NEEDLE TYPE  à  Needle valve is installed upstream of the enrichment jet and is operated by the throttle shaft.•AIR BLEED TYPE  à  If the size of the air bleed is decreased, the fuel/air mixture becomes richer.   Based on this, if you can control the size of the air bleed, you can control the mixture ratio. •ECONOMIZER SYSTEM •AIR BLEED ECONOMIZER •FLOAT TYPE CARB. LIMITTATIONS •LOW OPERATING PRESSURE, CAN RESULT IN COMPLETE VAPORIZATION AND INADEQUATE FUEL FLOW FROM DISCHARGE NOZZLE•DOES NOT RESPOND WELL TO SUDDEN A/C MANEUVERS AND UNUSUAL A/C ATTITUDE•TENDENCY TO ACCUMULATE ICE •TWO CATEGORIES OF CARB. ICING •FUEL EVAPORATION ICE•THROTTLE ICE •FLOAT TYPE CARB. MAINTENANCE •EXACT TYPE OF MAINTENANCE DEPEND ON :  1.  PROFICIENCY LEVEL  2.  THE AVAILABILITY OF REPLACEMENT
  PARTS  3.  THE AVAILABILITY OF REQUIRED   SERVICE EQUIPMENT • •BASIC TYPE OF CARB. MAINTENANCE INCLUDE PERIODICALLY CHECKING ALL CONTROL LINKAGES FOR FREEDOM OF MOVEMENT THROUGH THEIR  FULL RANGE OF MOTION. IN ADDITION YOU SHOULD EXAMINE THE FUEL LINES  AND AIR HOSES FOR KINKS, DISTORSION, OR INDICATIONS OF LEAKAGE•IDLE MIXTURE ADJUSMENTS•IDLE SPEED ADJUSMENTS •CARBURETOR OVERHAUL •DISASSEMBLY•CLEANING•INSPECTION•REASSEMBLY•INSTALLATION •PS7BD PRESSURE CARBURETOR •PRESSURE INJECTION CARBURETORS •DO NOT UTILIZE A FLOAT CHAMBER TO STORE FUEL•FUEL IS DELIVERED UNDER PRESSURE BY FUEL PUMP THROUGH THE CARBURETOR AND OUT THE DISCHARGE NOZZLE•NO NEED TO PLACE THE DISCHARGE NOZZLE DIRECTLY IN VENTURI. • •OPERATION AND DESIGN PRESSURE INJEC-TION CARBURETOR BERBEDA JIKA DIBANDING DG  FLOAT TYPE CARBURETOR NAMUN INDIVIDUAL SYSTEM MASIH DIPERLUKAN SPT  :    -  FUEL METERING  -  MIXTURE CONTROL  -  IDLING    -  ACCELERATION    -  POWER ENRICHMENT •MAIN METERING •THE FUEL REGULATOR/FUEL CONTROL UNIT•MAIN METERING JET•THROTTLE VALVE• •FUEL REGULATOR/FUEL CONTROL UNIT IS DEVICE RESPONSIBLE FOR METERING THE APPROPRIATE AMOUNT OF FUEL FOR ENGINE OPERATION.   A TYPICAL FUEL REGULATOR UNIT CONSISTS OF FIVE DISTICNT CHAMBERS, AN INNER AND OUTER DIAPHRAGM, A POPPET VALVE ASSEMBLY, AND A MAIN METERING JET ( FIG. 7-41)       •FUEL REGULATOR UNIT •IDLE NEEDLE VALVE •MIXTURE CONTROL •ACCELERATION SYSTEM •DOUBLE STEP IDLE VALVE •POWER ENRICHMENT SYSTEM • •FLOAT TYPE CARBURETOR DAN PRESSURE INJECTION CARBURETOR EXTREMELY RELIABLE NAMUN DEMIKIAN MASIH PUNYA KELEMA-HAN YAITU  :  1.  INTAKE MANIFOLD BERBEDA DALAM   PANJANG DAN BENTUK.  2.  RAWAN TERHADAP TERJADINYA    CARBURETOR ICING.• FUEL INJECTION SYSTEM •DIRECT FUEL INJECTION SYS.  à  FUEL IS
  INJECTED DIRECTLY INTO ENGINE CYLINDER . •KEUNTUNGAN  à   -  DISTRIBUSI MERATA          -  MENGURANGI BACK              FIRING *  KERUGIAN  à  -  TOLERANSI YG SANGAT        KETAT DARI PABRIK   -  COMPONENTNYA RUMIT   -  TDK PRAKTIS DAN MAHAL• •TYPE FUEL INJECTION YG PALING SERING DIGUNAKAN ADALAH  CONTINUOUS FLOW  FUEL INJECTION SYSTEM  à  FUEL INJECTED AND MIXED WITH AIR DALAM SETIAP INTAKE PORT SEBELUM INTAKE VALVE.   FUEL  IS CONTINUOUSLY INJECTED SELAMA COMBUS-TION CYCLE SBG PENGGANTI HANYA SELAMA INTAKE STROKE. •TYPES OF CONTINUOUS FLOW FUEL INJECTION 1.  PRECISION AIRMOTIVE RSA SYSTEM2.TELEDYNE CONTINENTAL SYSTEM   RSA FUEL INJECTION SYSTEM CONSISTS OF FIVE PRIMARY COMPONENTS  :  a.  Ventury housing  b.  Fuel metering unit  c.  fuel regulator  d.  Flow divider  e.  Several fuel nozzles• • •RSA FUEL INJECTION SYSTEM •BASIC COMPONENTS TELEDYNE CONTINENTAL SYSTEM 1.ENGINE DRIVEN INJECTOR PUMP2.FUEL / AIR CONTROL UNIT3.FUEL M,ANIFOLD VALVE4.INJECTOR NOZZLE •TYPICAL WET-SUMP SYSTEM •DRY –SUMP LUBRICATION •OIL RESERVOIR & GEAR TYPE OIL PUMP •GEROTOR TYPE PUMP & PRESS. RELIEF VALVE •LOCATION OF TYP. SERVICE ITEM ON DRY SUMP SYSTEM •BENDIX PS7BD PRESSURE CARBURETOR •REC. ENG. STARTING SYSTEM •INERTIA STARTER  à  ONE OF THE FIRST TYPES OF MECHANICAL ENGINE STARTING DEVICES USED IN AVIATION•DIRECT CRANKING STARTER  PROVIDES INSTANT AND CONTINUAL   CRANKING WHEN ENERGIZED.    THIS   ELIMINATES THE NEED TO STORE PRE-  LIMINARY ENERGY IN A FLYWHEEL •DIRECT CRANKING STARTER •SIDE MOUNTED STARTER •REC. ENG. IGNITION SYSTEM •BATTERY IGNITION SYSTEM  à  MENGGU-NAKAN BATTERY SBG SUMBER TENAGA LISTRIK.• •MAGNETO IGNITION SYSTEM  à  MENGGU-NAKAN ROTATING MAGNIT SBG PENGGANTI BATTERY • •BATTERY IGN. SYSTEM CONSISTS OF :  =  BATTERY  =  IGNITION COIL  =  BREAKER POINT  =  CAM  =  CAPACITOR  =  DISTRIBUTOR  =  SPARK PLUG •BATTERY IGNITION SYSTEM • •BASIC COMP. HIGH TENSION MAGNETO :  =  SINGLE HIGH TENSION MAGNETO  =  A WIRING HARNESS  =  SET OF SPARK PLUG•SINGLE MAGNETO  à  Consists of permanent magnit having two, four, or eight foles that are fixed to a single rotating shaft.•DUAL MAGNETO  à  Containts two indepen-dent ignition system that share a common ro-tating magnit.   In other word containts two of everything except rotating magnit and cam. • •FLASHOVER  à  Is term used to describe an occurrence inside a high tension magneto where a spark jumps to the wrong electrode in the distibutor block.•HIGH TENSION MAGNETO  à  Consists of mechanical system and three distinct circuit; a magnetic circuit, a primary electrical circuit, and secondary elactrical circuit. •HIGH TENSION MAGNETO SYSTEM •A SINGLE MAGNETO • •MAGNETO SPEED  à  Distributor rotor in a magneto always rotates at one-half the engine crankshaft speed.•   MAGNETO SPEED =  NUMBER OF CYLINDERS
   2 X NUMBER OF POLES   COMING IN SPEED  à  The speed at which a magneto must rotate to produce enough voltage to fire a spark plug.