190201a Engine Fundamentals

Question 1

who and when did they developed the 4 stroke cycles and what are they?
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Answer 1

in 1862 Beau De Rochas developed the 4 stroke cycles

• intake
• compression
• power
• exhaust

Question 2

who had a patent awarded to them for designing the compression ignition engine? and when?
when did he build the first successful 4-stroke cycle compression ignition engine?
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Answer 2

• It was Dr. Rudolf Diesel in 1892

- 1895 he was able to build the first 4-stroke compression ignition engine

Question 3

what did Thomas Gaff achieve and when?
what does Vickers LTD develop and when?
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Answer 3

• in 1913 Thomas Gaff tries the first solenoid-operated diesel fuel injectors
• in 1913 Vickers LTD develops the first common rail fuel system

Question 4

when did EGR (exhaust gas recirculation) begin?

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Answer 4

2004

Question 5

when did EPA (environmental protection agency) regulations state that on-highway engines manufactures must comply with tier 3 emissions?

when was the introduction of DPF (diesel particulate filters) and ULSF (ultra low sulphur fuel @15 ppm)?
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Answer 5

2007

Question 6

when are Interim Tier 4 emissions regulations implemented and the use of DEF (diesel exhaust fluids)?
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Answer 6

2010

Question 7

what year do all on-highway and off-highway engines must meet Tier 4 emissions regulations.
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Answer 7

2015

Question 8

what is the principal on witch a diesel engine operates?

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Answer 8

compression ignition - diesel fuel is injected into highly compressed air and the heat of compression ignites the fuel.

Question 9

Explain what compression ratio is.

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Answer 9

compression ratio is comparison of the volume above the piston when it is at BDC to the volume above the piston when it is at TDC

formula is CR = piston displacement + clearance volume / clearance volume

Question 10

explain clearance volume (CV).

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Answer 10

clearance volume is the volume remaining about the piston when it is at TDC (found in a service manual… not calculated by tech)

Question 11

explain Mean effective pressure (MEP).

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Answer 11

Mean effective pressure is the difference between pressure on the compression stroke vs cylinder pressure on the power stroke.

Question 12

explain volumetric efficiency (VE).

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Answer 12

volumetric efficiency is expressed as a percentage and is comparison between actual amount of air taken into a cylinder during the intake stroke divided by the actual cylinder volume. VE is limited to approx. 85% in naturally aspirated engines. A factor that effects volumetric efficiency is speed (less is better)

formula is volume of air taken in / actual cylinder volume X 100 = ____% VE

Question 13

explain thermal Efficiency.

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Answer 13

thermal efficiency is the ability of an engine to convert heat energy of a fuel into useable heat energy to push the piston down. 36% efficiency approx.

Question 14

explain horse power. and what are the imperial and metric units.
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Answer 14

horsepower is the amount work done in a given period of time.
imperial = hp
metric (SI units) = W or KW

one horsepower is 33,000 lbs x 1 foot x 1 sec
one watt is 1 Newton meter of work in 1 second (1 w = 1 N*m x 1 second

Question 15

explain mechanical efficiency.

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Answer 15

mechanical efficiency is the difference between indicated horsepower and brake horsepower. this indicates how much of the engine’s theoretical power is lost to overcome internal friction.

formula is brake horsepower / indicated horsepower x 100 = ___% ME