AMT 614: Aircraft Powerplant 1 PDF

# AMT 614: Aircraft Powerplant 1 (System and Components) ## WCC: Aeronautical & Technological College North Manila | CEAT: College of Engineering and Aeronautical Technology **Instructor:** R-D Angelo G. Garcia **CAAP License no.:** 101883-AMT **Rating:** Airframe & Powerplant ## Topic: Induction...

# AMT 614: Aircraft Powerplant 1 (System and Components) ## WCC: Aeronautical & Technological College North Manila | CEAT: College of Engineering and Aeronautical Technology **Instructor:** R-D Angelo G. Garcia **CAAP License no.:** 101883-AMT **Rating:** Airframe & Powerplant ## Topic: Induction System ## Resources and Disclaimers: * **JEPPSEN A&P TECHNICIAN POWERPLANT** * Chapter 5 Induction Systems * I do not take credit for any pictures, videos or diagrams attached in this presentation unless stated. ## Induction System The primary purpose of an induction system in a reciprocating engine is to provide air in sufficient quantity to support normal combustion. Reciprocating engine induction systems can be broadly classified as normally aspirated, super- charged, and turbocharged. ## Introduction * The induction system is designed to supply air to the engine. * Outside air passes through an air intake and is then routed to a carburetor or other fuel metering device. * Fuel/air mixture is delivered into an intake manifold where it is ducted to the cylinders for combustion. ## Normally Aspirated Systems * A typical induction system on a normally aspirated engine consists of four major components, or sections: * Air intake * Induction air filter * Fuel delivery system * Induction manifold * Additional subsystems such as: * Alternate air source * Ice removal or prevention system * Temperature indicating system, are typically included to support the operation of the four primary components. ## Air Intakes * Sometimes referred to as an air scoop, is designed to direct outside air into a carburetor or other fuel metering device. * Generally located to take advantage of ram air pressure as much as possible. * Usually found in the propeller slipstream because of the extra velocity. * Because of this pressure rise, a well-designed intake scoop can have a substantial effect on an engine's power output. ## Air Filtering * Typically installed in air intake ducts. * To prevent dust, sand, abrasive materials, or other contaminants from entering the engine. * Provide reliable operation and a long service life. ### Dust * Serious source of trouble for an aircraft engine. * Dust consists of small particles of hard, abrasive material. * Can cause: * Accelerated wear on cylinder walls and piston rings. * Silicon fouling of spark plugs. * Contaminate the oil. ### Once in the oil: * Further wear on bearings and gears. * In extreme cases, dust accumulation can clog an oil passage and cause oil starvation. * Dust may also collect in a fuel metering device and upset its ability to provide the proper mixture ratio at all power settings. ## Fuel Delivery System * Normally aspirated engine can be either a: * Carburetor * Fuel injection system * The purpose of a fuel delivery system is to meter the amount of fuel and air that is delivered to the cylinders. A complete discussion as to how the fuel and air are metered is covered in fuel system and metering. ## Intake Manifold * Typically consists of ducting. * Goes from the fuel metering device to the individual cylinders. * Connecting point of all the individual pipes which deliver air or fuel/air mixture to the cylinders. * One end of each cylinder's intake pipe is typically bolted to the cylinder intake port on each cylinder while the other end is attached to the manifold with a short section of synthetic rubber hose or rubber packing and packing nut. * Both of these methods permit some movement between the intake pipes and manifold as the cylinders expand and contract. * In some installations, the intake manifold goes through the oil sump before it branches out to go to each cylinder. * This increases the temperature of the fuel/air mixture which, in turn, promotes better fuel vaporization. ## One Very Important Characteristic of an Intake Manifold is that it must maintain a gastight seal. * If a seal is not maintained, air will leak into the intake manifold and lean out the mixture. * This, in turn, will cause an engine to run rough. * Small induction leaks are most noticeable at idle because the pressure differential between the manifold and atmosphere is greatest at low rpm.