QUOTE (kurt95gt @ Feb 28, 2012 - 5:09 PM)
Might get all the tools needed an practice on my extra 5s head an port match my exhuast manifolds
Get yourself some carbide bits, i tend to use the oval one shown the article the most, along with a some 80 grit tapes to use with a split fork deburrer ( piece of rod about 4 inches long with a slot hacksawed in the end) and maybe some cartridge rolls or a kit of them from standard abrasives and some ata bands.
Forget about port matching on the exhaust side, what you want ti see is an overlap all the way around the port, like a step so the gases flow out over it but cant easily come back in over it under reversion.
If the ports are matched itll make it easier for the ports to backflow and charge quality etc can be impacted on.
Unless theres a large instrusion/mismatch into the airstream on the intake ports, they probably wont need to be touched either.
Much more important is shape, size of them will in all likelihood be close to whats needed already, so just smoothing the casting marks off and removing sharp edges on the short side radius will do a good job of getting you a power improvement for not a lot of effort.
You can still apply the basics in the article to the 5sfe head.
Just to add, dont underestimate the advantages you can get by utizing a good valve seat combination.
Too many people just go get a "3 angle job" done without knowing if the angles used are working or not so speak to someone whos tested them on your engine, if theyve not done it then really youre shooting in the dark.
Since i built my own flowtester ive been able to gauge the impact of various valve seat modifications for the heads im currently working on (audi) and avoid the ones that dont work too well.
Heres a couple of curves i generated whilst testing a head for an engine build im doing.
First up, the modified seat combination vs the stock setup in blue.
As you can see, quite an improvement and the port hasnt even been touched, not cleaned nothing at that point.
Same port, different combination, flow is murdered at low lift and the port whistles like heck which you can see until it clears at around 4.0mm lift.
Thats the kind of thing you want to avoid at all costs.
Video of that port squealing as the valve is lifted, hard to appreciate how loud it actually is on the video but its starting to overload the mic on the camera.
http://www.youtube.com/watch?v=SyUio7RaL0Y