1quikZ

Ok, i know ill probably get lashed on this one but what the hell is port and polished , I hear it all the time and everyone makes reference to it but I have no idea what it is, how to do it and what kind of gains do you get from it?

turbo_Z

Port and polish refers to the modification done to cylinder heads. Basically there are 2 principle ingredients to making power... air and fuel. The more of both you can cram into a cylinder and successfuly ignite, the more power you are going to make(in theory).

So what guys will do is open up the intake and exhaust ports so they quite simply flow more air.. thats the port side of the equation. The work is then polished to get rid of grinding marks and a flat, smooth surface creates less turbulance than a rough surface to help the air move through the heads.

1quikZ

SStrokerAce

Actually most times it's just porting.

Companies like HVH charge a extra fee for Polishing ports. Guys like Phil at Ai, Lloyd, Craig at GTP and Larry Meaux never "polish" ports they only port the heads. Shape is more important than what it looks like.

Bret

zx1216

And polishing is only done on the exhaust side and the combustion chamber because it is actually good to have a slightly rough surface on the intake side to help mix the air and fuel.

turbo_Z

I never understood that statement. What "mixing" needs to take place exactly? It seems to me if you had a rough surface that may possibly trap some fuel in the intake runner.

zx1216

Yea, thats what i've heard all the time from lots of people, maybe bret will chime in with some of the theory behind it. I know you want to polish the exhaust side and chamber so carbon will not be able to build up on it as easily.

SStrokerAce

Carbon build up always happens. Nothing you can do about that.

Polished chambers are supposedly going to keep clean and reflect the heat into the chamber. TBC does a better job at this and it never stays clean but it does a awesom job at keeping heat in the chamber. Heat = energy and a motor is a horiblly inefficent device at converting heat into energy or TQ.

If anything the short side would like to be polished with slight grooves along the runner from intake to valve in it.

There is a boundry layer of air there that keeps the moving air from ever touching the surface of the port so the surface finish of the port really doesn't mean dick.

Bret

1quikZ

ok now that I know "what it is", how is it done, Is this something I can do myself or should I get it done professionally somewhere like a machine shop?

sssalah

It’s either done with CNC machining or by hand using a die grinder and different rotary bits. You can do a port job yourself, but with all respect it will end up to be a lousy job, and it’s very tedious. I’ve tried and ported the LT4 heads I have, and they ran decent, but lately choose to give Lloyd a try and paid almost $500 for shipping both ways. The look of the ports is awesome and the flow numbers are nothing short, how about 304 cfm. Give it to the pros you wont be disappointed.

ShawnMacAnanny

You can blow more air through a McDonald's straw than you can blow through a Wendy's straw, reason being the Mcdonald's straw has a larger diameter.

RamAir95TA

Well...yeah.

I've also heard that pouring sand in your throttle body will port and polish the heads far better than any porter that walks this earth.

Just kidding. Some good info in this post.

Fastbird93

But given the same lung capacity of the blower, I bet you that the wendy's straw would carry more velocity.

unvc92camarors

i thought it was the other way around
you wanted to make it as easy for the air to get in as possible, and for the exhaust it didn't really matter

ShawnMacAnanny

Mcdonald's food is twice as unhealthy as Wendy's food. People that eat there regularly are fatter. Fatter people need to breathe more. They also need to drink more, hence the larger straw. McDonald's knows it, that's why they engineered the plus sized straw.