( Automotive engineering : Vehicle components , Engine, transmission, and exhaust )
The maximum compression pressure in the piston is controlled by the clearance volume.
When the piston is at top dead center, the clearance volume is at a minimum. When the piston moves to bottom dead center, it is at a maximum.
The nominal volume of the combustion chamber above the piston when it is at the top
dead center is the clearance volume.
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