i never questioned why he polishes the internals. i questioned the pointless random cuts under the boost port. very mild polishing is fine, but extreme polishing isnt a good thing its mostly done for photos and stuff like that. I know of a modder who mods engines and he does a rough polish around the intake ports. He doesnt polish it much at all nor polish it in other areas as it will remove material and the tolerance of the sleeve in the case more loose. After a few tanks of fuel the sleeve will turn dull looking. Rougher surfaces make the air more turbulant when in the motor this increases Fuel atomization which is a good thing. but there is a difference in that and a interuption of airflow. I dont like the fact mark polishes what looks like the entire sleeve and makes the cuts i seen but oh well thats his game and what he does and i respect him like i do all modders, i just use the one i like and fits my need the best.