INTERNAL COMBUSTION ENGINES EXTERNAL VS INTERNAL external combustion

INTERNAL COMBUSTION ENGINES

EXTERNAL VS INTERNAL external- combustion engine typically steamed powered heated water would produce steam to increase pressure in a piston therefore pushing it to turn a wheel

EXTERNAL VS INTERNAL CONT. Internal- powered by controlled explosions Multiple cylinders turn a crank shaft to produce rotary force that turns the wheel

BASICS OF INTERNAL COMBUSTION ENGINE Gas and oxygen are pumped into cylinder as piston goes down Gas and oxygen are compressed as piston moves up Spark plug ignites, creating explosion and pushing piston down Exhaust is pumped out as piston goes back up Four stroke engine

BASICS CONTINUED Why four strokes? Why not just one cylinder?

HOW IS A TWO STROKE DIFFERENT? Both input and output valves are open at the same time Less efficient, unused gas is let out Lightweight Less parts

PARTS WORKING IN UNISON Timing belt allows everything to work in unison

CARBURETOR VS FUEL INJECTION Carburetor in older model cars. Puts fuel into engine by creating pressure differences. mechanical

CARBURETOR VS FUEL INJECTION CONTINUED Modern way of getting fuel into engine More efficient Electronically controlled

OCTANE RATING Measurement of “knockback resistance” When compression of piston happens, temperature increases, and can possibly cause premature explosion. This is how diesel engines work (minus the premature part). Messes up piston cycle. Higher octane means greater tolerance for higher temperature via higher pressure