Reciprocating Engines

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29 Νοε 2013 (πριν από 3 χρόνια και 11 μήνες)

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Reciprocating Engines

Recips


Romans invented the reciprocating engine in
Saw mills that lined rivers.


The concept was adapted to the heat engine
and ultimately the steam engine.


Around the late 1800’s some German guys get
the picture.

First Options

Back to Reality

Lets Brake It Down


Engine Case


Holds everything that
makes up the engine


Accessories and items
are either bolted on,
or held in via bearings.


Made of aluminum


Cylinders


Cylinders house
pistons, rods, valves


Cylinders are made of
steel


Cylinder integrity is of
the utmost
importance

Pistons


Made of Steel


Provide the
resistance and force
in combustion.


Connect to the
crankshaft via a
connecting rod.


Crankshaft


Steel forged unit of the engine which
transmits lateral force into rotary force.


The key to the reciprocating engines design

Camshaft


Used to ensure proper engine timing


Gear driven by the crankshaft

Valves


The camshaft controls the lifters which in turn
control the valve timing.


Exhaust valves and intake valves have different
angles and sizes



Spark Plugs


Create the ignition
event

Bearings


Allow for a thin film
of oil to separate two
metal bodies


Several Types


Ball


Roller


Thrust


Radial


Plain


Accessory Case


All gear driven accessories come off of either
the front of rear of the engine.

Two Stroke Engine

Otto Cycle


You may know
more provocative
terminology but for
our case
Nikolaus

Otto invented the
first practical use 4
cycle engine.


Broken Down

http://
flash.aopa.org/asf/engine_prop/swf/flash.cfm?WT.mc_id
=100806epilot&WT.mc_sect=sap

What’s in a Name


AEIO 540 L1B5


Aerobatic


Horizontally Opposed


Fuel Injected


540 Cubic Inch Displacement



IOF

240 B5B


Fuel Injected


Horizontally

Opposed


Fadec

Controlled


240

Cubic Inch Displacement


Identifiers


H


Helicopter


R


Radial


T


Turbocharged


S


Supercharged


V


Vertical


E


Experimental


L


Left Turning


F


Fan Cooled


Displacement


Stroke
x

(.5
x

Bore)
2
x

π

x

Number of Cylinders

Compression Ratio


The pressure difference between TDC and BDC


Finding Engine compression is generally the
easiest way to determine the health status of
an engine


Compression testing is done every 100Hr or
Annual

Compression Test


Mechanics

use
differential pressure to
determine how good
the cylinder is
retaining pressure.


Shop pressure

is set to
80psi, the piston is
brought to TDC


We

read the prevailing
pressure on the
other
gauge


We

want as close to
80psi as possible


Engine

should be
warm

Trouble

Making Metal

Bad


Aluminum flakes will not be picked up


Steel will be picked up

Lean while Taxiing

Detonation Vs. Pre Ignition


Pre Ignition is the burning of the fuel air
mixture prior to the desired



Detonation is an uncontrolled fuel
burn

Hot Stuff


Don’t Lean too Much