Other Internal Combustion Engines Without Spark Plugs
Many model airplanes use very simple "glow" and "Diesel" engines. Glow engines use glow plugs. "Diesel" model airplane engines have variable compression ratios. Both types depend on special fuels (easily obtainable in such limited quantities) for their ignition timing.
Some 19th-century or earlier experimental engines used external flames, exposed by valves, for ignition, but this becomes less attractive with increasing compression. (It was the research of Nicolas Léonard Sadi Carnot that established the thermodynamic value of compression.) A historical implication of this is that the Diesel engine would eventually have been invented without the aid of electricity.
See the development of the hot bulb engine and indirect injection for historical significance.
Famous quotes containing the words spark, internal, combustion and/or engines:
“Thou waitest for the spark from heaven!”
—Matthew Arnold (18221888)
“I believe that there was a great age, a great epoch when man did not make war: previous to 2000 B.C. Then the self had not really become aware of itself, it had not separated itself off, the spirit was not yet born, so there was no internal conflict, and hence no permanent external conflict.”
—D.H. (David Herbert)
“The night has been unruly. Where we lay,
Our chimneys were blown down, and, as they say,
Lamentings heard i th air, strange screams of death,
And prophesying with accents terrible
Of dire combustion and confused events,
New-hatched to the woeful time.”
—William Shakespeare (15641616)
“America is like one of those old-fashioned six-cylinder truck engines that can be missing two sparkplugs and have a broken flywheel and have a crankshaft thats 5000 millimeters off fitting properly, and two bad ball-bearings, and still runs. Were in that kind of situation. We can have substantial parts of the population committing suicide, and still run and look fairly good.”
—Thomas McGuane (b. 1939)