My Powerplant 8001-8050

If the crankshaft runout readings on the dial indicator are plus .002 inch and minus .003 inch, the runout is

.005 inch

A nine-cycliner engine with a bore of 5.5 inches and a stroke of 6 inches will have a total piston displacement of

1,283 Cubic Inches

Using the following information, determine how many degrees the crankshaft will rotate with both the intake and exhaust valves seated.

245 degree

Ignition occurs at 28 degrees BTDC on a certain four-stroke cycle engine, and the intake valve opens at 15 degrees BTDC. How many degrees of crankshaft travel after ignition does the intake valve open? (consider one cylinder only.)

373 degrees

The volume of a cylinder equals 70 cubic inches when the piston is at bottom center. When the piston is at the top of the cylinder, the volume equals 10 cubic inches. What is the compression ratio?

7:1.

What will be the likely result if the piston ring gaps happen to be aligned when performing a differential-pressure compression check on a cylinder?

A worn or defective ring(s) indication.

1)Cast iron piston rings may be used in chrome-plated cylinders. 2) Chrome-plated rings may be used in plain steel cylinders.

Both No. 1 and No. 2 are true.

How is proper end-gap clearance on new piston rings assured during the overhaul of an engine?

By placing the rings in the cylinder and measuring the end-gap with a feeler gauge.

What is a characteristic of a thrust bearing used in most radial engines?

Deep-groove ball.

What are factors in establishing the maximum compression ratio limitations of an aircraft engine

Degree of supercharging

An aircraft reciprocating engine using hydraulic valves liftersis observed to have no clearance in its valve operating mechanism after the minimum inlet oil and cylinder head temperatures for takeoff have been reached. When can this condition be expected?

During normal operation

On which strokes are both valves on a four-stroke cycle reciprocating aircraft engine open?

Exhaust and intake.

The operating temperature valve clearance of a radial engine as compared to cold valve clearance is

Greater

What is a condition that can occur in radial engines but is unlikely to occur in horizontally opposed engines is

Hydralic lock.

What will decrease volumetric efficiency in a reciprocating engine?

Improper valve timing, Sharp bends in the induction system and High carborator air temperatures.

The five events of a four-stroke cycle engine in the order of their occurrence are

Intake, compression, ignition, power, exhaust

What is the condition that would be the least likely to be caused by failed or failing engine bearings

Low oil tempatures.

What is least likely to be a roller or ball bearing?

Master rod bearing (radial engine)

What statement is correct regarding engine crankshafts?

Moveable couterweights serve to reduce the torsional vibrations in an aircraft reciprocating engine.

On which part of the cylinder walls of a normally operating engine will the greatest amount of wear occure?

Near the top of the cylinder

Master rod bearings are generally what type?

Plain

Grinding the valves of a reciprocating engine to a feather edge is likely to result in

Preignition and burned valves.

What will be caused by excessive valve clearance of a cylinder on a reciprocating aircraft engine?

Reduced valve overlap period.

When is the fuel/air mixture ignited in a conventional reciprocating engine?

Shortly before the piston reaches the top of the compression stroke.

What is statement is correct regarding a four-stroke cycle aircraft engine?

The intake valve closes on the compression stroke.

Why does the smoothness of operation of an engine increase with a greater number of cylinders?

The power impluses are spaced closer together.

If the hot clearance is used to set the valves when the engine is cold, what will occur during operation of the engine?

The valves will open late and close late

What is benefit regarding bearings used in high-powered reciprocating aircraft engines

There is less rolling friction when ball bearings are used than when roller bearings are employed

What tool is generally used to measure the crankshaft rotation in degrees?

Timing disk.

What is the purpose of a power check on a reciprocating engine?

To determine satisfactory performance.

What is the principle advantage of using propeller reduction gears?

To enable the engine RPM to be increased with an accompanying increase in power and allow the propeller to remain at a lower, more efficient RPM.

What is the purpose of the safety circlet installed on some valve stems?

To prevent valves from falling into the combustion chamber.

During overhaul, reciprocating engine exhaust valves are checked for stretch with

a contour or radius gauge

The valve clearance of an engine using hydraulic lifters, when the lifters are completely flat, or empty, should not exceed

a specified amoutn above zero

If an engine with a stroke of 6 inches is operated at 2,000 RPM, the piston movement within the cylinder will be

at maximum velocity 90 degree after TDC.

If the intake valve is opened too early in the cycle of operation of a four-stroke engine, it may result in

backfiring into the induction system

Full-floating piston pins are those which allow motion between the pin and

both the piston and the small end of the connecting rod

The actual power delivered to the propeller of an aircraft engine is called

brake horsepower

If the exhaust valve of a four-stroke cycle engine is closed and the intake valve is just closed, the piston is on the

compression stroke.

Compression ratio is the ratio between the

cylinder volume with piston at bottom dead center and at top dead center.

Valve overlap is defined as the number of degrees of crankshaft travel

during which both valves are off their seat

The purpose of two or more valve springs in aircraft engines is to

eliminate valvespring surge.

If fuel/air ratio is proper and ignition timing is correct, the combustion process should be completed...

just after top center at the beginning of the power stroke.

Some cylinder barrels are hardended by

nitriding

The primary purpose in setting proper valve timingand overlap is to

obtain the best volumetric efficiency and lower cylinder operating temperatures.

Cam-ground pistons are installed in some aircraft engine to

provide a better fit at operating temperatures

Some aircraft engine manufacturers equip their product with choked or taper-ground cylinders in order to

provide a straight cylinder bore at operating temperatures.

The primary concern in establishing the firing order for an opposed engine is to

provide for balance and eliminate vibration to the greatest extent possible.

When cleaning aluminum and magnesium engine parts, it is inadvisable to soak them in solutions containing soap becuase

some of the soap will become impregnated in the surface of the material and subsequently cause engine oil contamination and foaming.

During overhaul, the disassembled parts of an engine are usually degreased with some form of mineral spirits solvent rather than water-mixed degreasers primarily becuase

water-mixed degreaser residues may cause engine oil contamination in the overhauled engine.