Port and Polish - How to do it? What do you need?

[Nexagen]

How can I port and polish the heads in an engine? What tools would I need and what steps do I need to take?

-Thanks

[SnakekanS]

i'd like to know that too since its pretty expensive and i could prolly do it myself since i have access to a dealer garage anytime i want

[pro_am]

If you go to amazon.com or barnes and nobles/borders they have books there for like $20.00 that show in great detail how to do it, and maximize your gain from it.
Jake

[SnakekanS]

there must be free info somewhere on the net

[MagicRat]

Okay, here's some free info.
A Dremel tool (with a remote cable drive is best) and a variety of carbide and stone cutting and polishing wheels.
Porting a head involves removing metal from the intake and exhaust passages in the cylinder head.
If you do it correctly, air and exhaust flow will increase.
However, air flow dynamics are extremely complicated. You cannot just make the passages 'larger'. Often, its the shape and contour of the passages that determine flow, not just size.
Also, in a carbureted or TBI engine, the intake passages shoud remain a little rough. However, on an port fuel injected car and all exhaust passages can be made completely smooth.
The most valuable tool is a flow bench. This device sucks air through the port at a specific pressure, and measures airflow. This allows you to see if the porting you have done has made any difference.
Without a flow bench, you are completely in the dark.
Sometimes, you can make some crude improvements, that is duplicate some basic porting changes that someone has already flow tested on the identical engine to yours.
It is also very easy to remove too much material and grind right through into a coolant passage. Then your cylinder head is mostly junk.
Polishing is just getting a smooth finish in the combustion chamber. This is easier to do, and in theory increases flow slightly. Butr it is most helpful if you are raising compression ans it slightly reduces the chance of detonation (ping)

My suggestion is to sent the head out to a machine shop who really know what they are doing.
Otherwise its lots of work with no guarentees for any improvement.

[SaabJohan]

It's usually best to use a pneumatic tool like this

they to however require a compressor. If the head is made from aluminum the last bit of removal of material usually goes faster than one might think.

The best is of course using a CNC machine to remove material, but that is usually to complex and costly for most people.

Material can also be added to the head in form of welds and plastic material.

I would probably not recommend more than a "small polish" to anyone who doesn't know how to do it. To get the most of a head job it usually also requires different cam shafts, perhaps larger valves and so on.

By "polishing" it one can remove "defects" caused by casting, in many cases the intake doesn't match exactly to the head, this can also be solved and one can chose the surface finish.

[Mex-i-carnage]

Forget using a Dremel as air tools are far better.

Go here as the DIY porting guide and pics are excellent..

http://www.sa-motorsports.com/diyport.htm


Mex-i