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delgato · 02-25-2009, 07:40 PM

Kazin111

I am porting my head right now.
Is Port/polish worth it? Well it does give gains of course as long as you do not screw up the flow. I tend to "port" only by cutting off sharp edges or burrs, seams get smoothed. Little chance of messing up the flow that much.
Polish by going from 80-120-240-320 grit. The intake should not be polished, per se, but the exhaust you can go all out. I tend to run out of steam and do not go mirror smooth. Back to the intake, its best to keep a certain very slight roughness to increase surface area, which encourages fuel/air swirling. So I keep it at 320grit. For the mirror smooth exhaust you need compounds.

To do this easily yourself you need an air comp, a Harbour freight $15 die grinder and 1 long Eastwood mandrel (~$5) and sanding cartridges ($6 ea for 10 ea) from 80-320. Also, BUT not necessary are aluminum cutting bits. This takes out the big chunks but the BT head does not have much of that. Pretty clean head, but still needs cleaned up.
Afterward the seats need AT LEAST lapped, possibly ground. I do not have the tools for that so I am super careful. (I do lapp though) So far I have been lucky not to accidentallygrind the seats.

I will post some photos later of my port/polish and the tools I use.
Its really not hard so much as you just need patience, tools and time.

02-25-2009, 07:40 PM	#3 (permalink)
delgato No Skills Join Date: Jan 2009 Location: USA Posts: 13 Thanks: 5 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	Kazin111 I am porting my head right now. Is Port/polish worth it? Well it does give gains of course as long as you do not screw up the flow. I tend to "port" only by cutting off sharp edges or burrs, seams get smoothed. Little chance of messing up the flow that much. Polish by going from 80-120-240-320 grit. The intake should not be polished, per se, but the exhaust you can go all out. I tend to run out of steam and do not go mirror smooth. Back to the intake, its best to keep a certain very slight roughness to increase surface area, which encourages fuel/air swirling. So I keep it at 320grit. For the mirror smooth exhaust you need compounds. To do this easily yourself you need an air comp, a Harbour freight $15 die grinder and 1 long Eastwood mandrel (~$5) and sanding cartridges ($6 ea for 10 ea) from 80-320. Also, BUT not necessary are aluminum cutting bits. This takes out the big chunks but the BT head does not have much of that. Pretty clean head, but still needs cleaned up. Afterward the seats need AT LEAST lapped, possibly ground. I do not have the tools for that so I am super careful. (I do lapp though) So far I have been lucky not to accidentallygrind the seats. I will post some photos later of my port/polish and the tools I use. Its really not hard so much as you just need patience, tools and time.