Small Engine Basics I

SMALL ENGINES

HISTORY  Scottish inventor, James Watt – developed concept of

horsepower

 Namesake of “watt” unit of power  Expanded Newcomen steam engine (late 1700s)  1800s – first crude internal combustion engines developed in

Western Europe

 Evolved to run on gasoline and kerosene  Early 1900s – Briggs & Stratton developed revolutionary

stationary Type “P” engine

 Game changer for 4-cycle gas engines; set course to

become world’s largest manufacturer of air-cooled gasoline engines  Engine powered washing machines, garden tractors,

cultivators, and generators  1953 – Briggs & Stratton revolutionized lawn and garden

industry by developing 1 st lightweight, air-cooled aluminum engine  Further advanced in 1958

 1970s – development of electric motors and one of the 1 st

gas/electric hybrid car prototypes (Briggs & Stratton)

SMALL ENGINES  All shapes and sizes  Used to power:  Outboard motors  Weedwackers/mowers  Motorcycles  Small generators  Chainsaws  Concrete mixers

IMPORTANT SMALL ENGINE PARTS  Cylinder head  Spark plug  Carburetor  Muffler  Crankshaft  Dipstick  Starter  Air-filter  Crankcase  Fuel tank  Camshaft  Piston  Valves  Connecting Rods  Flywheel

SMALL ENGINE PARTS

SMALL ENGINE PARTS

HOW ENGINES WORK  Power and energy made by

burning mix of fuel and air in cylinder

 As fuel burns, it explodes and

pushes piston down in the cylinder

 Piston is attached to crankshaft

that turns as the piston moves up and down

HOW ENGINES WORK

ENGINE CYCLE  Common in most all engines:  Intake: fuel and air pushed/sucked into cylinder  Compression: fuel-air mix compressed as piston moves up  Ignition/Power: spark ignites fuel-air mix; explosion pushes the piston down  Exhaust: burnt gasses are pushed out through exhaust

 https://www.briggsandstratton.com/na/en_us/support/videos/browse/4-cycle-th

eory.html