Originally Posted by therotaryrocket

why would polishing the intake be bad? I guess it depends on the car. My autotech teacher rebuilt the 3 cylinder engine in his geo metro and polished everything including the intake manifold, throttle body, pistons, combustion chambers, head, he's getting like atleast 75 mpg and alot more power. i guess your saying polishing would take out the turbulence in air flow, which you want, but i would guess from the spiral intake tracts/runners on a briggs and straton engine (lawnmower?) that the velocity increase is just as important so wouldn't the air entering the engine enter at a higher velocity if the intake had less turbulence? please inform me