Hi guys, I just got a set of 9 carbide bits (for $35 ! on ebay, what a deal) , plus the Standard Abrasives deluxe port/polish kit. I am working on a set of 081 heads to use on my Stealth Rammed 327. I gasket matched the heads to Fel Pro 1205s, which is the port size of the Stealth Ram I'm using. I am starting to flatten all of the casting bumps, of which there are many ,in the intake runners. I am also smoothing the huge ridges left by the factory valve pocket cutters. The ridges in the intake ports are at least 1/8" protrusions. Anyhow, to my question. I was reading posts on this board about porting factory iron heads, and it is agreed upon that taking around 10ccs out of the pocket/bowl itself is a good idea, to make a teardrop shape. Here is a picture of the carbides I have -- what should I be using to carve around the valve guide? How deep should I go? Then blend into the runner? I assume I am doing all of the bowl work right through the valve hole?

 

Seems to be a decent selection.

If u want to do anything than port matching to the gasket and the bowls, your gonna need some longer shanks. Might want to find a slightly larger ball bit too.

I have about a dozen or so ferrous(iron) and non ferrous(alum) bits with originally 6 inch shanks that I cut down as needed. Have other ones that are the original 3,4 or 6 inch length.

Any type of deep blending in the ports or working the short turn radius and a few other areas, and your gonna need some more reach than what u have currently.

Stones work great when dealing with the cast iron heads to for clean up work and keeping a nice shape that you someitmes cant quite manage with the bits.

later
Jeremy

 

If those are solid carbide burrs, that's a heck of a deal. I'd probably use #7 the most, but others in specific areas. #1 might be good around valve guide bosses. #3, 8, and 9 might be good down the port runners to raise the roof and open the walls along the push rod humps. #4 should be good for working over the short side raidii above the valve seats.

I've given up on opening valve bowls with burrs and stones, and just plunge a cutter to hog out the bowls, then finish the shape with burrs and stones. It's just a lot faster and more consistent. You can even get piloted versions of cutters that operate just like valve seat cutters.

 

Vader, they are solid carbide burrs, they work great. I gave up on teardropping the pocket, I just don't have the right tools or the time. I basically gasket matched, removed casting bumps all the way through, and opened up the intake and exhaust pockets right up to the valve seats, a lot. The factory cutter left huge ridges in the pockets. I felt safe running the carbides up to barely 1/8" below the valve seats, and I didn't damage any of them. I used the standard abrasives kit to smooth the area around the valve stem, but I didn't remove much material there. I did cut the valve guide bosses down to a more tapered shape with the carbides. The exhaust side didn't look all that bad (even though it flows pretty awful), I opened the bowls up a little, and then did a full mirror polish on the ports.