I want to LIGHTLY port match my heads to the intake on my SBC. The head port shapes are so far off it isn't even funny. They are trapazoids. In some corners I need to remove 3/16 inch to make them rectangular. Can I use stone to cut the cast iron? (harbor freight cheappo kit) If not, where do I by the right bits at the best price?
Screw the stones!!... You'll be there for ever.. Buy some carbide double-cut burrs for a die grinder and also some 36 grit sanding rolls with an arbor to mount those on.. There's a good company out there that sells a great kit you can buy... I'll have to look them up...
Check this site out..... www.diyporting.com Then click on "tools of the trade"... They do show stones on there, but I never use those...
I HAVE BEEN LIED TO!!!!!!! I was told that this was an all day, 12 beer job. I have not even had one beer yet and one head is done. I used the cheap Harbor freight stones and they cut well. One head took about 45 minutes. I just matched the ports, nothing more. Held the gasket in place and used a tiny screwdriver to scribe the head. (FYI the head is not thin, there is paint on the edge of the head) Here are the before and after pics...
Jeepers----3/16" seems more than "lightly". If you go that much you may want to taper things some. Just eyeball what you think is good flow surfaces and taper them out without altering any of the "inside angle" curves. By the sound of it you should be able to improve things a bunch. Remember, it's the learning to do this stuff is where the value lies. Have fun---GEEZER
They are a set of 882 truck heads that I already have and am using on my 400 project. The intake is a Edelbrock performer. The machine shop gave me the correct gasket to use as a template. Basically I just got rid of the square edges in the flow path as the picture shows. It is tapered, but not drastically. I did not remove any material past 1/2 inch into the port. Most of the material I removed was near the edge. I kept feeling the wall thickness to make sure I didn't do anything stupid. Maybe others would remove more, but it is smooth and far better than bolting them on as-is. I used the stones on my die grinder and two small files to finish it out. It was easy, but then again, I build lots of fiberglass parts and use the die grinder extensively to form the finished parts. One head to go...but first I need to drink 10 beers.
I think I will leave them alone. It is already nicely blended in. The small files (one round, one triagular) really did the trick to take out any high spots.
You are on the road to success. The stone finish is superior. The cartridge roll too smooth. You rightly sugested that you didint want gobbs of metal hanging out in the airstream . You were right on that. Most of the rest of the ponies hide in the pocket under the valve. Keep up the good work. Don
The Machine shop inspected my work and they liked it. They told me to remove a little more material buy the valve cove bolt bulge and take a bit more off the raduis in the corners.
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