Toro 303447 - Four-Stroke Stroke Details

INTAKEstrok e:ontheintakeorinductionstrokeofthepiston,thepistondescendsfromthetopofthe
cylindertothebottomofthecylinder,reducingthepressureinsidethecylinder.Amixtureoffuelandair,
isforcedbyatmosphericpressureintothecylinderthroughtheintakeport.Theintakevalve(s)then
close.Thevolumeofair/fuelmixturethatisdrawnintothecylinder,relativetothevolumeofthe
cylinderiscalled,thevolumetricefficiencyoftheengine.
Detail
PistonmovesfromTDCtoBDC
Intakevalveopen
Exhaustvalveclosed
Pistonmovementcausesanareaoflow
pressuretodevelopinthecombustionchamber.
Higherambientatmosphericpressureforcesairthroughtheintakesystem.
Ingascarburetedenginetheairpicksupthefuelasitpassesthroughthecarburetor.
Ingasfuelinjectedenginesthegasisaddedtotheairthroughaninjector.
InDiesel
enginesthefuelisinjectedintothecylinderattheendofthecompressionstroke.
180degreesofrotation
Anythingthatrestrictstheflowofairwillreduceengineperformance.