Porting?
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
Porting?
It means you grind out some metal to increase the size of the intake & exhaust journals (ports) in the cylinder head to increase the flow (decrease pressure) thru them. You have to be VERY careful not to remove too much metal because you can weaken the head or cause hot spots if you don't know the thickness of the casting and how heat flows thru the metal.
You'll usually hear "porting & polishing" used together. Since the factory does as little machining as it can (to keep costs down), they leave the surfaces of the ports rough, just like they are after the sand casting process that forms them. It's common to smooth out these surfaces, especially after a porting job, to further reduce the friction against the air & exhaust flowing across them.
You'll usually hear "porting & polishing" used together. Since the factory does as little machining as it can (to keep costs down), they leave the surfaces of the ports rough, just like they are after the sand casting process that forms them. It's common to smooth out these surfaces, especially after a porting job, to further reduce the friction against the air & exhaust flowing across them.
