port and polish?

[harro_VR]

hey everyone im just wondering what a port and polish does and if it has any advantages and also a rough price on getting it done. as one of my mates was talking about it. i have a 94 vr berlina auto.

thanx harro

[WILD VR CLUBBY]

it smooths out the air intake and polishes it up so you get a nice even air flow im preety sure u can get it done to the water jackets as well. you could also do a rougth job your self but it aint wise unless u know what your doin

[hoarey85]

i hav a very little amount of expience with this, but it depends on how you want it done. For instance if you get it done professionally you would get a flow rate done, but if you just wanted to play around with it yourself and you could get some beta throttle response and power but you wouldn't hav it on paper to say i hav these.. if you know what i mean?

[shaggerz]

"port" and "polish" are two different things that are usually done at the same time.

Due to mass production techniques, where the intake manifold bolts to the cylinder head for example, the intake ports dont quite line up evenly and there is some overlap. This restricts the flow of air into the engine, which reduces power output. "Porting" can be done on any metal to metal joins on the intake path, for example, intake manifold to cylinder heads, throttle body to intake manifold, supercharger to intake manifold, etc.

Porting refers basically to opening up the intake paths in these metal components by either cutting a larger hole in the metal or just enlarging it so there is no metal overlap to make more room for the air to flow through.

"Polish" is what it sounds like. It involves polishing the surface of the combustion chamber in the cylinder head so that it is smoother. This has the benefit of reducing hotspots, which discourages pinging, and also prevents the mixture, carbon deposits, etc from sticking to the head.

[sircruisealotVS]

well, what it is has pretty much been covered....
as for how much it cost its not cheap, and also not entirely worth while unless you put a cam in at the same time...which inturn requires a new tune to make that worth while, lol.
but basically for a GOOD port and polish, tested on a flow bench and having the manifold port matched you'd be looking at around $1200-1500+ all up. but like i said, if you were going to port your heads, you really should invest in a cam too (so more money for that as well...)