You want to know how to port? If thats the case, just buy some CNC'd champions. Seriously. The heads on your car shouldnt be the test bed for your first port job. It takes experience, fluids knowledge and the steady hand of a surgeon to do it right. If you want some advise to tell the porter,....if he needs advise, he shouldnt be your porter. But i'll throw a few tips anyway. Raise the roof of the runner to the gasket. Clean the flash off the floor, and leave it lumpy. A slightly lumpy surface flows better than a polished one. Look at a golf ball. Its designed that way for a reason. Deepen the valve pocket, and make sure the roof of the runner transitions perfectly into the bowl without hitting a bump or going into a pit first. If the runner curves, remove material from the short side of that curve, because the long side has very low velocity, and you'll make it worse if you remove material. Just remove flash from the long side. Make sure the radius of curvature is consistent as it sweeps around the rim of the bowl. Its best to leave this work up to a knowledgable guy with a Serdi seat cutter. The part of the guide that sticks into the runner...if it sticks out more than stock, cut it down to the stock position, or a little past that. Then cut all the surrounding iron into an airfoil around the guide. Make the transition of the runner floor into the valve pocket as smooth as possible. There are usually lips on that short side curve. Remove them and make that curve smooth with no disruptions in the radius. Have the serdi guy use a performance cut for the seats...the one that uses a curve instead of an angle on the bottom cut, instead of the typical 60 degree cut. If you look at Honda heads, (they flow VERY well for what they are), you'll see they pretty much have no material past the 45. This creates a very large valve pocket. You can copy this, but you have to worry about available meat...you dont want to poke through into a water jacket. Thats why I recomment the Serdi performance cut. It creates a little venturi instead of a gaping pocket with no velocity. If you want your valves to seal REALLY well, you want them to break in really well. You do that by cutting a small interference angle. The seat should be 45 degrees, and the valve should be 44.5. The valves will NOT leak if you do this. You cut the seat and the valve. then stick the valve into the guide, and smack the valve against the seat several times, then pull the valve out and look at the witness line that was just made on the valve face. It should about 1-1.5mm away from the outer edge, and the line should NOT be chattered. It needs to be a solid line all the way around. If the line is chattered, you have a problem with the valve grinder stone. Now if you want to flow really well at low lifts, have the shop cut the 45 degree angle almost completely gone with a 30 degree angle. Then cut the 44.5 angle, and then a 15. This will give you about another 15-20cfm at low lifts.
Also, do NOT let the shop knurl your guides to make them "like new". Thats BS. Your guides will last about 5 minutes after you fire it up. Have them put in NEW, IRON guides before they cut the seats.
Then of course make sure the spring pressures are all good, the head is decked square....all the obligatory ****.
