Porting and Polishing

[SmoothSteve3]

Hey everyone-

 

Ok, I'm the first to admit that I'm VERY naive about internal engine work (probable because I've never rebuilt one). What is meant when people say they are going to port and polish their intakes/valve heads? The polish part is pretty self explainatory, but what about the porting part? Are they just making the intake holes bigger? or what?

Thanks!

 

SmoothSteve

[PaPaPooh]

yes they are making them bigger and the polishing them on the intake and on the heads

[brother pig]

Another method used is to scribe the opening of the gasket on the both the intake and exhaust ports of the head. The opening is then enlarged to the size of the gasket to allow maximum airflow. This enlarged opening is then blended into the original size of the runner for about an inch or so into the head.

I have also heard that the intake runner should be kept a little rough, to keep the fuel/air mixture mixed. This would only help on a non port injected engine though

Also, the combustion chamber can also be polished to slow down the accumulation of carbon deposits, and to avoid hot spots on the head that could lead to detonation.

I've never personally done any of this; I have only seen them done on a race car that someone I new built. (it wasn't a w-body....sorry)

I hope this helps....maybe someone else will have something to add also.

[PaPaPooh]

yea brother said it better than me

[no1kicker]

Anyone know how much a machine shop would chagre to do this? I want to port the intake manifold, plenium, and heads.

[topless94style]

It would be expensive its pretty labor intensive and takes a long time to do.

[Intlcutlass]

I was quoted $900, I thought that was insane.... I have heard that $500-$600 is not uncommon..... I have not hade this done yet for that reason.....