In a four-stroke engine, during the suction (or intake) stroke (1) the piston moves from the top of the cylinder toward the bottom. ... Both the four-stroke and two- stroke engines types discussed so-far use spark ignition to achieve combustion.
|Title||:||Airplane Aerodynamics and Performance|
|Author||:||Jan Roskam, Chuan-Tau Edward Lan|
|Publisher||:||DARcorporation - 1997|