have ?'s on porting

[F.BEJARANO]

What is the difference between port/polish and boring? when ever you port ive seen that the area where the reeds go into gets opened bigger but what else is done. will i have to buy new pistons or do you only have to do it when you bore? boring just makes the cylinder holes where the head goes onto bigger right? sorry for the dumb questions but have no idea on how this works and want to port my bike in about 2-3 months. thanks

[Wildcardracing]

The cylinder bore is where the piston goes, you only want to have your cylinders bored if it's necissary to clean them up for a rebuild. Port and polish is completely different, This is where metal is removed from the ports (holes in the cylinder that the intake and exhaust charges flow in and out of) to increase performance. The polishing should only be done to the exhaust side.

[chevrolet banshee]

Yes wen you bore you increace the size of thr hole that the piston is in, also you have to get bigger pistons. To port you make the holes in the cylender (the ports) larger and diffrent shapes, It depends on what kinda power you want to make. Polishing is not needed on the intake and some times a ruff port can help (I have no clue why but it dos). a bore will not gane you power but a port job will be night and day.

 

Chevshee

[dajogejr]

You don't polish the intake side because it will cause gas to bead up on the metal, rather than atomize into the cylinder.

 

You only bore a cylinder if you had a no no (broke piston, etc.) or if it is outside of clearance specs.

 

Porting is, as said, changing the shape and often size to get air and fuel in and out of the motor more efficiently.