Engine Fundamentals & Operating Cycles
What is considered the foundation of an aircraft engine?
The Crankcase
What is another name for a piston pin?
Wrist Pin
What color indicates a chrome-plated cylinder barrel?
Orange
What is used to help prevent valve surge or valve float?
Two or more springs are used on each valve
What is the measurement shown in Figure A?
.666
What are the five operational events of a four-stroke (Otto Cycle) engine?
Intake
Compression
Ignition
Power
Exhaust
Full-floating piston pins allow motion between which components?
The piston and the connecting rod
What color are nitrided cylinder barrels painted?
Blue
What type of tappets are needed for the valve mechanism assembly in Figure 11?
Hydraulic
What is the measurement shown in Figure B?
.545
What is a compression ratio?
Ratio of the volume of the cylinder at TDC and BDC
What material are most piston rings made from?
Gray cast iron
What is a choked-bore cylinder?
Narrow at the top of the cylinder and wide at the bottom
Why are some exhaust valves filled with metallic sodium?
Heat Dissipation
What is the measurement shown in figure C?
.627
What is the first valve action after the ignition event?
Exhaust valve opens
What test is being performed in Figure #6?
Piston Diameter
What test is being performed in Figure #4?
Diameter of Bore
What is the purpose of valve overlap?
It allows better volumetric efficiency and lowers cylinder operating temperatures
When checking the diameter of a cylinder bore, how many measurements should be taken?
At least two, 90 degrees apart
With an exhaust valve lead of 55 degrees and a lag of 15 degrees, how long is the valve open using the power "W"?
250 degrees
What test is being performed in Figure #2?
Ring side clearance
Why are many cylinders choke-bored?
Because of differential Thermal Exanpsion
The contour gauge, or Micrometer, shown in Figure #5 is being used to check for what?
Valve Stretch
What type of cylinder is shown in Figure 10?
Choke cylinder