Reciprocating Engine Induction and Cooling Systems

Carburetor air scoop

During full power output of an unsupercharged engine equipped with a float-type carburetor, in which of the following areas will the highest pressure exist?

density of air in the cylinder increases.

As manifold pressure increases in a reciprocating engine, the

It is possible to exceed 100 percent volumetric efficiency of some engines by the use of superchargers of the proper type

Which of the following statements regarding volumetric efficiency of an engine is true?

Improper adjustment of carburetor heat valve control linkage

Which of the following would be a factor in the failure of an engine to develop full power at takeoff?

30 "Hg

Boost manifold pressure is generally considered to be any manifold pressure above

maximize the aerodynamic efficiency of the inlet.

The purpose of a bellmouth compressor inlet is to

Sharp airflow directional change to take advantage of inertia and/or centrifugal force, and filters or engine inlet screens.

What method(s) is/are used to provide clean air to the engines of helicopters and turboprop airplanes that have particle (sand and ice) separators installed?

Continue cranking the engine

If a fire starts in the induction system during the engine starting procedure, what should the operator do?

circulating the fuel and air mixture through passages in the oil sump.

On small aircraft engines, fuel vaporization may be increased by

Too much cooling fin area broken off

Which of the following defects would likely cause a hot spot on a reciprocating engine cylinder?

Exhaust valve port

What part of an air-cooled cylinder assembly has the greatest fin area per square inch?

A fan mounted on the engine

Reciprocating engines used in helicopters are cooled by

Carried out with the exhaust gases

The greatest portion of heat generated by combustion in a typical aircraft reciprocating engine is

may be filed to smooth contours if damage and/or repair limits are not exceeded.

A broken cooling fin on a cylinder head

Idle RPM

An engine becomes overheated due to excessive taxiing or improper ground runup. Prior to shutdown, operation must continue until cylinders have cooled, by running engine at

Thermocouple sensing device

Cylinder head temperatures are measured by means of an indicator and a

A very lean mixture at high power settings

High cylinder head temperatures are likely to result from

foreign material buildup on spark plugs

Prolonged idling of an engine will usually result in

Machining fins directly on the outside of the barrel

The most common method and generally the best conduction of heat from the inside of a cylinder barrel to the cooling air is accomplished by

A device to cool an engine accessory.

What is the function of a blast tube as found on aircraft engines?

Part-throttle operation

Which of the following results in a decrease in volumetric efficiency?

provide for greater heat transfer to the engine oil.

The undersides of pistons are frequently finned. The principal reason is to

Decrease

Increased engine heat will cause volumetric efficiency to

In the induction system or the exhaust system

When a fireguard is standing by during an engine start, they should be watching for potential fires that could start

Preheat the intake air

A method commonly used to prevent carburetor icing is to

a. preheat the intake air.

b. mix alcohol with the fuel.

c. electrically heat the venturi and throttle valve.

Air temperatures between 30 and 40 degrees Fahrenheit

Carburetor icing is most severe at

The airstream ahead of the carburetor.

Into what part of a reciprocating engine induction system is deicing alcohol normally injected?

A decrease in manifold pressure with a constant RPM

Carburetor icing on an engine equipped with a constant-speed propeller can be detected by

Carburetor

What part of an aircraft in flight will begin to accumulate ice before any other

Alcohol spray and heated induction air

Carburetor icing may be eliminated by which of the following methods?

A transient increase in engine power

Bootstrapping of a turbocharged engine is indicated by

all the exhaust gases are directed through the turbine.

If the turbocharger waste gate is completely closed,

Limits the maximum manifold pressure that can be produced by the turbocharger at full throttle.

What is the purpose of the density controller in a turbocharger system?

Controls the rate at which the turbocharger discharge pressure will increase

What is the purpose of the rate-of-change controller in a turbocharger system?

Waste gate

What directly regulates the speed of a turbocharger?

Compresses air to maintain manifold pressure constant from sea level to the critical altitude of the engine.

What is the purpose of a turbocharger system for a small reciprocating aircraft engine?

Exhaust bypass assembly, density controller, and differential pressure controller

What are the three basic regulating components of a sea-level boosted turbocharger system?

reduces bootstrapping during part-throttle operation.

The differential pressure controller in a turbocharger system

Upper deck pressure

The pressure between the turbocharger and the throttle valve is called

limit the amount of air that can flow from the turbocharger into the cabin for pressurization.

The purpose of a sonic venturi on a turbocharged engine is to

The aircraft will not be able to reach its critical altitude

If a turbocharger waste gate is not able to close fully,

Cause engine surges due to an erratic manifold pressure

A malfunction that causes the turbocharger waste gate or controller to fluctuate will

To aid in cooling the engine

What is the purpose of an augmenter used in some reciprocating engine exhaust systems?

May be repaired by removing the affected area and contour filing within limits

Cracks in cooling fins that do not extend into the cylinder head

Engine manufacturer's service or overhaul manual

Which of the following should a mechanic consult to determine the maximum amount of cylinder cooling fin that could be removed when cracks are found?

left alone if no crack has formed.

A bent cooling fin on an aluminum cylinder head should be

Cylinder head, cylinder barrel, and inside the piston

Where are cooling fins usually located on air-cooled engines?

May be stop drilled

Generally, a small crack just started in a cylinder baffle

True

Some aircraft exhaust systems include an augmenter system to draw additional air over the engine for cooling?

1 multiple choice option

True

Augmenter systems are used to create a low pressure area at the lower rear of the aircraft engine cowling.

1 multiple choice option

Gear train from the crankshaft.

What is used to drive a supercharger?

Silicon fouling of spark plugs

In addition to causing accelerated wear, dust or sand

ingested by a reciprocating engine may also cause

system will automatically allow warm, unfiltered air to be drawn into the engine.

In an airplane equipped with an alternate air system, if the main air duct air filter becomes blocked or clogged, the

The engine to not start and a loss of engine power

if an engine air filter element is not routinely cleaned and becomes excessively dirty, it can cause

None is required

Where would a carburetor air heater be located in a fuel injection system?

Ice was forming in the carburetor

An increase in manifold pressure when carburetor heat is applied indicates

A decrease in power and possibly detonation

The use of the carburetor air heater when it is not needed causes

Mixture will become richer

If carburetor or induction system icing is not present when carburetor heat is applied with no change in the throttle setting, the

COLD

When starting an engine equipped with a carburetor air heater, in what position should the heater be placed?

Decrease the weight of the air-fuel charge

The application of carburetor heat during engine operation will

The mixture will become richer

The application of carburetor heat will have which of the following effects?

Enriching the mixture until the AMC can make a compensation.

When operating an engine, the application of carburetor heat will have what effect on the air-fuel mixture?

Loss of power and possible detonation

A carburetor air pre-heater is not generally used on

takeoff unless absolutely necessary because of the

Exhaust gases

One source commonly used for carburetor air heat is

It controls all positions of the waste gate except at fully open position

Which of the following is a function of the differential pressure controller?

Increase the pressure of the incoming air by ram effect

The action of a carburetor airscoop is to supply air to the carburetor, but it may also

Controls the amount of air flowing around the cylinders

How do cowl flaps aid in cooling a horizontally opposed aircraft engine?

Closed

The position of the cowl flaps during normal cruise flight condition is

Fully open

During ground operation of an engine, the cowl flaps should be in what position?

Flap actuator motor circuit breaker

During an operational check of an electrically powered radial engine cowl flap system, the motor fails to operate. Which of the following is the first to be checked?

Full open at all times

What is the position of the cowl flaps during engine starting and warmup operations under normal conditions?

force cooling air into close contact with all parts of the cylinders.

The primary purpose of baffles and deflectors installed around cylinders of air-cooled aircraft engines is to

cooling

Aircraft reciprocating engine cylinder baffles and deflectors should be repaired as required to prevent loss of

A baffle and cowl arrangement

Which of the following assists in removing heat from the metal walls and fins of an air-cooled cylinder assembly?

air entering the carburetor from the turbocharger.

The purpose of an intercooler when used with a turbocharger is to cool the