engine port and polish (PnP)

engine porting and polish (PnP)

porting n polish (PnP) is a manual hand work that aim to improve the volumetric efficiency of a machine.

volumetric efficiency is a quantity in percentage (%). it's a mixture of air & gas that obtained on the engine.

example : for a 2000cc engine with 70% volumetric efficiency mean : each cylinder (500cc) engine they will be charged 70%x500cc mixture of air and gas.

volumetric efficiency of the N/A engine will not reach 100% due to the number of barriers from the flow of mixture of air and fuel from the intake manifold,valve,air intake,throttle body,etc.

standart engine from the factory usually only 70% volumetric efficiency, with PnP the volumetric will more improved up to 80%-85%.

because of more efficient, that's mean will produce better performance. so,the assumption that the PnP become wasteful is wrong (if the PnP do correctly), because usually aftar the PnP, the driver is so happy to open the throttle deeply and make the car more wasteful. but if using the car with normal condition, fuel consumption would be more efficient because more efficient engine performance.

if you want Volumetric efficiency more than 100% can be obtained by force induction (turbo, supercharge)