Using Small Engines. Next Generation Science/Common Core Standards Addressed! CCSS.ELA...
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Transcript of Using Small Engines. Next Generation Science/Common Core Standards Addressed! CCSS.ELA...
• Using Small Engines
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.
Agriculture, Food and Natural Resource Standards Addressed!
PST.02.01. Perform preventative maintenance and scheduled service to maintain equipment, machinery and power units used in AFNR settings.
PST.02.01.01.b. Develop a preventative maintenance schedule for equipment, machinery and power units used in AFNR power, structural and technical systems.
Bell Work / Student Learning Objectives
Identify the reasons why small engines are widely used.
Describe how small engines can be classified.
Identify common service jobs performed on small engines.
Terms
Blow-by
Degreaser
Dry-filter type air cleaners
Horizontal crankshaft engine
Oiled-filter type air cleaners
Service intervals
Vertical Crankshaft engine
Interest Approach
How could we accomplish lawn tasks without small engines?
Small engines
Implements with less than 25 horsepower.
Several million are now in use in the U.S., both two and four cycle
Accomplish tasks that other equipment cannot do. New items are continually being developed.
Small engine popularity
Compact
Lightweight
Easy to service and repair
Affordable
Reasons for small engine trouble
Dirt and dust leads to rapid wear if not serviced properly.
Abuse by overloading.
Do not receive proper service or regular maintenance.
Small engines usually operate at top speed continuously. That would be comparable to you car traveling at 85 mph continuously.
Classifying small enginesBy the position of their crankshafts
By the number of power strokes per crankshaft revolution
Position of crankshafts
Vertical crankshaft engine – its cylinder is in a horizontal position
Horizontal crankshaft engine – may have its cylinder in a vertical, horizontal, or intermediate position
Multi-position crankshaft engine – operates in any position
CrankshaftPositions
Number of power strokes
Four stroke cycle engines – intake, compression, power, exhaust
Two-stroke cycle engines – compression & intake, power & exhaust
Extremeanglesof operationand oilsupply
Common service jobs
Cleaning the engine
Inspect and clean the exhaust system Degreaser – solvent good for cleaning hard to reach places
Inspect cooling system for obstructions
Servicing carburetor air cleaners
Oil-filter type air cleaner – made of a sponge-like filtering material called polyurethane
Dry-filter type air cleaner – consists of a porous filtering material made of paper or fiber
Types ofair cleaners
Lubricating small engines
Engine oil is vital to engine lifeBlow-by – gases under pressure that leak by the piston rings during combustion and the power stroke
Four cylinder engines are lubricated from an oil reservoir
Two-cycle engines are lubricated by specific types of oil mixed in the fuel
Lubrication Systems.
Servicing spark plugs
Anything that inhibits the flow of current through the spark plug and across the spark plug gap will affect the operation of the engine.
Sparkplugoperation
Review/Summary
Why are small engines so widely used?
How are small engines classified?
What are some of the common service jobs performed on small engines?
The End!