Recip Midterm Mod 1-6

Question 1

what are the two types of cylinder valves

Answer 1

Intake - where air/fuel mixture enters the piston

exhaust - where exhaust gasses leave the cylinder

Question 2

what is the otto cycle

Answer 2

the standard compression cycle in a piston engine. 4 or 2 stroke

Question 3

what is compression ratio

Answer 3

comparison of the volume of space in a cylinder when piston is at BDC and TDC.

increase in manifold pressure = increase in compression ratio

Question 4

TDC

Answer 4

top dead centre

Question 5

BDC

Answer 5

bottom dead centre

Question 6

2 main types of oil pumps

Answer 6

gear pump and Gearotor pump

Question 7

how do you calculate compression ratio

Answer 7

volume of cylinder at BDC divided by volume of cylinder at TDC

Question 8

what is horsepower? how do you calculate it

Answer 8

horsepower is standard unit of mechanical power

1HP = foot-pounds divided by 33,000

Question 9

what is plank

Answer 9

P = IMEP
L = Length of stroke in feet
A = area of piston  
N = # of power strokes per minute
K = Number of cylinders

Question 10

what is the difference between break and indicated horsepower

Answer 10

Indicated HP - theoretical, does not account for friction.

Break HP - actual horsepower delivered by the engine to the propeller

Question 11

what are the 6 functions of oil

Answer 11

reduce friction
absorbs heat
seals
cushions
cleans
protects against corrosion

Question 12

flash point

Answer 12

temp when oil gives off ignitable vapors

Question 13

cloud point

Answer 13

temp when wax separates and solidifies into crystals

Question 14

fire point

Answer 14

temp when there are sufficient vapors to support a flame

Question 15

pour point

Answer 15

lowest temp at which oil can flow or be poured

Question 16

how is oil classified

Answer 16

classified by a number that indicates viscosity. higher number = higher viscosity

Question 17

viscosity

Answer 17

a liquids ability to flow. higher viscosity means thicker liquid that is more resistant to flow

Question 18

what are the 4 types of oil

Answer 18

Straight mineral oil
ashless dispersant
multi viscosity
synthetic

Question 19

2 types of oil systems

Answer 19

wet sump - all oil held within crankcase of the engine. more simple system

dry sump - separate oil tank. most common in radial engines. requires more components such as scavenge pump

Question 20

what is a pressure relief valve

Answer 20

a valve that maintains a constant pressure in the oil system. adjusted by screw or washer thickness

Question 21

3 types of check valves

Answer 21

ball
cone
swing

Question 22

bypass valves

Answer 22

used to allow oil to bypass oil cooler until the oil is brought up to temperature

Question 23

2 types of oil filters

Answer 23

full flow and bypass

Question 24

what is SOAP

Answer 24

Spectrometric Oil Analysis Program

Question 25

what are the different types of icing

Answer 25

throttle ice - forming neat butterfly valve

fuel evaporation ice - causes moisture released by evaporation to freeze i

impact ice - visible moisture striking an aircraft and freezing