This slight opening and closing creates {HEAD ~ a shock wave} that aids {TAIL ~ the atomizing air and fuel mixing} in the intake system prior to normal intake valve opening and enhances the scavenging of combustion gases during the exhaust cycle 
aids
This slight opening and closing creates { HEAD ~ a shock wave } that aids { TAIL ~ the atomizing air and fuel mixing } in the intake system prior to normal intake valve opening and enhances the scavenging of combustion gases during the exhaust cycle
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