porting polishing facts?

[225DXfreak]

how does porting and polishing increase hp or make things run better in the engine? i'd like to know how this fancy stuff works because it sounds interesting.
the only thing that i know, and i dont know if its true is that polishing helps keep the heat inside the chamber instead of dissipating out through the head, which helps the fuel combust or something

[smokinwrench]

Porting is the process of removing material from the intake and exhaust ports, so the engine can breath easier. This alows more air to enter and exit the engine faster, in turn you can install bigger carbs and beter exhaust to give more power.

Polishing is just shining up the ports so the air/fuel mixture flows easier and faster with less turbulance.

[BIG BAD RED]

but less turbulance also makes less atomization...there is a art to doing it...and it is not just taking big chuks of meat out of it...

[$"|"I|\|G|2@?]

increased airflow, exhaust porting allows exhaust gasses to leave easier creating less back pressure. intake porting removes rough spots providing a freeer smoother surface for the atomized mixture to flow through adding horsepower.

[225DXfreak]

him, very interesting... how do you polish inside those ports?

[Mr. Richard]

WELL ,, I will tell you, if you opened up your motor took a dremel and messed around for a couple of hours grinding and polishing ,,, when you got done it might run worse,,, a general "cleanup" usually won't do enough to even notice,, that is something best left up to those motor builders that specialize in that,,,,, sometimes making ports smaller builds more horsepower too,,, so if you want a ported head let a pro do it,,,,,,

[225DXfreak]

ok thanks for the info

[Black Sheep]

Originally posted by kasey
WELL ,, I will tell you, if you opened up your motor took a dremel and messed around for a couple of hours grinding and polishing ,,, when you got done it might run worse,,, a general "cleanup" usually won't do enough to even notice,, that is something best left up to those motor builders that specialize in that,,,,, sometimes making ports smaller builds more horsepower too,,, so if you want a ported head let a pro do it,,,,,,

well said Kasey. thank you. if i had said that i would have gotten an ear full. so i kept my mouth shut. i would like to add that if your talking about a four stroke motor a proper port job cannot be done without a flow bench. a two stroke is differant. to add to Kasey's statement of a general cleanup. all that does it basically bring the ports to factory spec. after many castings of cylinders and heads the molds get dirty and the ports are not perfect from when the mold was designed. a cleanup removes casting flaws.

[82atc110]

If I were you I would leave my head alone until I did more research. That being said, go to www.sa-motorsports.com/diyport.htm . This is an automotive focused site but a lot of knowlege is to be had. I think anyone is capable of a basic cleanup+.

P.S. you don't have to use a flow bench although it helps, and two strokes are as important as four strokes. Ever hear of port timing and intake velocity?