A&P Prepware Powerplant Exam Questions
and Answers
If an engine operates with a low oil pressure and a high oil
temperature, the problem may be caused by a -
correct answer ✅leaking oil dilution valve.
At what speed must a crankshaft turn if each cylinder of a four-
stroke cycle engine is to be fired 200 times a minute? -
correct answer ✅400 RPM.
By use of a differential pressure compression tester, it is
determined that the No. 3 cylinder of a nine-cylinder radial engine
will not hold pressure after the crankshaft has been rotated 260
degrees from top dead center compression stroke No. 1 cylinder.
How can this indication usually be interpreted? -
correct answer ✅A normal indication.
Which condition would be least likely to be caused by failed or
failing engine bearings? -
correct answer ✅Low oil temperatures.
An increase in manifold pressure with a constant RPM will cause
the bearing load in an engine to -
correct answer ✅increase.
,A&P Prepware Powerplant Exam Questions
and Answers
Excessive valve clearance in a piston engine -
correct answer ✅decreases valve overlap.
The primary purpose in setting proper valve timing and overlap is to
-
correct answer ✅obtain the best volumetric efficiency and lower
cylinder operating temperatures.
Valve clearance changes on opposed-type engines using hydraulic
lifters are accomplished by -
correct answer ✅push rod replacement.
If metallic particles are found in the oil filter during an inspection, -
correct answer ✅the cause should be identified and corrected
before the aircraft is released for flight.
What is the principal advantage of using propeller reduction gears?
-
correct answer ✅To enable the engine RPM to be increased with
an accompanying increase in power and allow the prop to remain
at a lower, more efficient RPM.
,A&P Prepware Powerplant Exam Questions
and Answers
Full-floating piston pins are those which allow motion between the
pin and -
correct answer ✅both the piston and the small end of the
connecting rod.
What conditions will cause an engine to have an increased
tendency to detonate? -
correct answer ✅High manifold pressure, high intake air
temperature, and engine overheated.
Which of the following is a characteristic of a thrust bearing used in
most radial engines? -
correct answer ✅Deep-groove ball.
Some cylinder barrels are hardened by -
correct answer ✅nitriding.
Master rod bearings are generally what type? -
correct answer ✅Plain.
, A&P Prepware Powerplant Exam Questions
and Answers
Direct mechanical push-pull carburetor heat control linkages should
normally be adjusted so that that the stop located on the diverter
valve will be contacted -
correct answer ✅before the stop at the control lever is reached in
both HOT and COLD positions.
The purpose of two or more valve springs in aircraft engines is to -
correct answer ✅eliminate valve spring surge.
Cam-ground pistons are installed in some aircraft engines to -
correct answer ✅provide a better fit at operating temperatures.
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? -
correct answer ✅7:1
If the ignition switch is moved from BOTH to either LEFT or RIGHT
during an engine ground check, a normal operation is usually
indicated by a -
correct answer ✅slight drop in RPM.
and Answers
If an engine operates with a low oil pressure and a high oil
temperature, the problem may be caused by a -
correct answer ✅leaking oil dilution valve.
At what speed must a crankshaft turn if each cylinder of a four-
stroke cycle engine is to be fired 200 times a minute? -
correct answer ✅400 RPM.
By use of a differential pressure compression tester, it is
determined that the No. 3 cylinder of a nine-cylinder radial engine
will not hold pressure after the crankshaft has been rotated 260
degrees from top dead center compression stroke No. 1 cylinder.
How can this indication usually be interpreted? -
correct answer ✅A normal indication.
Which condition would be least likely to be caused by failed or
failing engine bearings? -
correct answer ✅Low oil temperatures.
An increase in manifold pressure with a constant RPM will cause
the bearing load in an engine to -
correct answer ✅increase.
,A&P Prepware Powerplant Exam Questions
and Answers
Excessive valve clearance in a piston engine -
correct answer ✅decreases valve overlap.
The primary purpose in setting proper valve timing and overlap is to
-
correct answer ✅obtain the best volumetric efficiency and lower
cylinder operating temperatures.
Valve clearance changes on opposed-type engines using hydraulic
lifters are accomplished by -
correct answer ✅push rod replacement.
If metallic particles are found in the oil filter during an inspection, -
correct answer ✅the cause should be identified and corrected
before the aircraft is released for flight.
What is the principal advantage of using propeller reduction gears?
-
correct answer ✅To enable the engine RPM to be increased with
an accompanying increase in power and allow the prop to remain
at a lower, more efficient RPM.
,A&P Prepware Powerplant Exam Questions
and Answers
Full-floating piston pins are those which allow motion between the
pin and -
correct answer ✅both the piston and the small end of the
connecting rod.
What conditions will cause an engine to have an increased
tendency to detonate? -
correct answer ✅High manifold pressure, high intake air
temperature, and engine overheated.
Which of the following is a characteristic of a thrust bearing used in
most radial engines? -
correct answer ✅Deep-groove ball.
Some cylinder barrels are hardened by -
correct answer ✅nitriding.
Master rod bearings are generally what type? -
correct answer ✅Plain.
, A&P Prepware Powerplant Exam Questions
and Answers
Direct mechanical push-pull carburetor heat control linkages should
normally be adjusted so that that the stop located on the diverter
valve will be contacted -
correct answer ✅before the stop at the control lever is reached in
both HOT and COLD positions.
The purpose of two or more valve springs in aircraft engines is to -
correct answer ✅eliminate valve spring surge.
Cam-ground pistons are installed in some aircraft engines to -
correct answer ✅provide a better fit at operating temperatures.
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? -
correct answer ✅7:1
If the ignition switch is moved from BOTH to either LEFT or RIGHT
during an engine ground check, a normal operation is usually
indicated by a -
correct answer ✅slight drop in RPM.
