fastsspr

iTrader: (49)

Extrudhone is a process which uses a chemical abrasive material which will eat the material from head porting walls. Resulting in a smooth surface increasing airflow true the heads. Years back was process that many people talked about. Anyone did this to their heads? and what was the results?

The Alchemist

iTrader: (19)

Having too smooth of an intake runner is not a good thing, it actually hurts the mixing effect of air/fuel into the combustion chamber.
If you're going to go through the time and hassle of removing the heads and re-installing them, just pick up a set of LS6 heads used, have them milled a little to bump compression, and you'll be 1000x better than trying to mess with the stock heads.

Darkman

iTrader: (2)

For what it is worth - I had my LS6 exhuast manifolds extrude honed and requested the maximum process. Having seen the "before" and "after" exhaust manifolds, I can report that the extrude hone process does not remove very much material. Specifically, the "before" manifolds had a rust coating on the interior and the "after" manifolds were smoother and shiney with a brushed texture, but some trace rust remained at the bottom of some of the brush marks. In other words the extrude hone process only removes material approximately equal to the depth of normal rust penetration into cast iron.

So, if your goal is a smooth surface the extrude hone may be of some use, but if your goal is to open up passage ways in terms of airflow by making things bigger, extrude honing is not particularly effective.

mattj

I come from a old-school SBC background and I remember when extrude honing came about. Like Darkman said, removes very little material and was helpful in S/S classes where rules dictated the cylinder heads couldn't be ported. You'd be much better off paying somebody to clean up the bowls or something.

speedtigger

iTrader: (16)

Extrude hone charges waaaaaaay too much money for what little they do for manifolds and cylinder heads. I would say the customer is what really gets "honed".

Isolde

iTrader: (4)

Extrude-Honing exhaust manifolds has to be modest, or there's risk of the manifolds cracking. They don't want a bad rep, nor getting sued.
Send them some thick aftermarket iron heads, they can take much much more.
The prices are insane, but their volume is low.
It's a catch 22, and they refuse to fix it.
If they'd drop prices, they'd get more business. But they're waiting for more business so they won't see any short-term loss. That's why they're dying out of the automotive scene.
Bunch of dumbarses who can't exploit their wonderful invention.

fastsspr

iTrader: (49)

Yes you are rigth. I alredy both a used set of LS6 that i'm wating in my mail. But remebered about extrude hone because back in a day many people talking about that. I going to send my castings to fully port them. Now is a shop in Miami called Breathless Performance that they port the heads and after that they do extrude hone them. I don't have the intention to do it because of the price. And now watching what your opinion are about it , i not even going to look there.
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