Lesson 3

Measuring Engine Components and Specifications

Next Generation Science/Common Core Standards Addressed!

CCSS.ELA Literacy.RST.9‐10.1 Cite specific textual evidence to support analysis of science and technical texts, attending to the precise details of explanations or descriptions.

CCSS.ELA Literacy.RST.9‐ 10.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks, attending to special cases or exceptions defined in the text.

CCSS.ELA Literacy. RST.11‐12.2 Determine the central ideas or conclusions of a text; summarize complex concepts, processes, or information presented in a text by paraphrasing them in simpler but still accurate terms.

CCSS.ELA Literacy.RST.11‐12.3 Follow precisely a complex multistep procedure when carrying out experiments, taking measurements, or performing technical tasks; analyze the specific results based on explanations in the text.

HSNQ.A.3 Choose a level of accuracy appropriate to limitations on measurement when reporting quantities. (HS‐PS1‐2),(HSPS1‐4),(HS‐PS1‐5),(HS‐PS1‐7)

HSSIC.B.6 Evaluate reports based on data. (HS‐LS2‐6)

Bell Work / Student Learning Objectives

Identify measuring and testing equipment for internal combustion engines.

Identify the specifications of an internal combustion engine.

Explain four major specifications to be checked on small engines.

Terms

Compression gage

Dial indicator

Flat feeler gage

Inside micrometer set

Micrometer caliper

Plastigage

Round-wire gage

Tachometers

Telescoping gage

Torque wrench

Interest Approach

How are internal combustion engine specifications determined?

Tools used in measuring engine components

Inside micrometer – determines the inside of a cylinderMicrometer caliper – precision measuring tool for taking outside measurements. Flat feeler gage – recognizes the spacing between two surfacesDial indicator – recognizes the spacing between two surfaces and records readings of the dial needle

Engine Tools (continued)

Round-wire gage – used in measuring the electrode gap of spark plugs

Plastigage – a thin, plastic, threadlike material used to measure the clearance between the bearing journal on a crankshaft and the bearing rod cap

Engine Tools (continued)Compression gage – helps in determining if there is a problem with the cylinder or piston rings.

Compression gauge It measures compression pressure inside the cylinder in pounds per square foot.

Torque wrench –a wrench designed to measure turning force (torque) placed on fittings.

Engine Tools (continued)

Telescoping gage – a tool used for measuring inside diameter

Tachometers – used for reading revolutions per minute

Telescoping Gage

Specifications of an internal combustion engine

Charts detail the exact specification to increase performance and prolong life

Related to engine size and work requirements

Clearances of the intake and exhaust valves

Four major specifications on small engines

Fuel

Oxygen

Compression

Ignition

Fuel

Use the fuel recommended by the manufacturer

Guidelines for older engines with carburetor adjustments:

Turning valve clockwise creates leaner fuel mixture

Turning valve counter clockwise creates richer fuel mixture

OxygenEngines need to take in clean air in order for combustion to occur.

Air filters should be routinely checked and cleaned

Compression

Not having compression indicates a serious problem in the engine

Quick test method with a small engine: pull the starter rope. If there is no resistance against the starter rope, the engine lacks compression

Ignition

Routinely check spark plugs

Clean the electrodes with a wire brush

If reinstalling spark plugs, the plug gap should be adjusted properly

Review/SummaryWhat are some of the instruments used for measuring internal combustion engines?What are the specifications of an internal combustion engine?What are four major specifications that are commonly checked on small engines?

The End!