Can someone post a high res picture of an intake and exhaust bowl of a fully ported SBC stock iron head? I home ported some 305 heads but I did not do too much to the bowls other than blend the radii, and blend the valve stem guide. I want to see what the correct general shape is of a fully ported stock SBC iron head intake and exhaust bowl.

Thanks!

Steve

 

thirdgen.org tech article:

http://www.ws6transam.org/ported.html

I think it works, anyway. I can't check it from my work ISP (internet firewall, for some reason).

 

I saw that page, the pics are way too small to really tell much. Those are home porting that look like what I have accomplished so far. Like mine, it doesn't look like any attention in particular is paid to the shape of the bowls.



Stuff like this:





Those are SBC but I have no idea what type of heads they are. I see that on the intake bowl, they are leaving a ridge towards the entrance of the bowl, and not grinding that down smooth. I am not sure what that does but it must be important.

Those pics were from http://www.maximumraceengines.com. I was just using them for reference.

 

The top picture is your work? Looks the best of all of them.

You don't need to reshape the bowl. Just smooth out the cast-to-machining interfaces, smooth out the short-side radius, and put the "airfoil" around the guide.

 

LOL no none of those are my work. I was just using them for the example of how an "airfoil" shape like you describe, is made around the guide. In order to make that shape, the area around the pointy ridge from the airfoil, must be removed.

I'd like to know what shape cutter I should be using (small round, oval, flame shaped, christmas tree, etc), and whether I should be working entirely through the valve pockets or whether I should be using a really long shank carbide and working through the ports. I had no trouble pocket porting the heads but when it came to shaping the bowls, I pretty much stopped. I'll try to get a pic of one of my bowls later tonight. They are not particularly pretty.

 

I used a flame shaped one for most of my work.
The christmas tree comes to a point, which makes it tough to use in the bowls.
Those are GORGEOUS work on those pics. Whoever did them is a master. I don't have steady enough hands to do that airfoil.

You can only get 3" shank and 6" shanks for the most part. I take a 6" and lop an inch or two off. 6" is too long and really wants to wobble.

I use a 1/2" cylinder with ball end on a 3" shank for most of the close quarters stuff (chamber, edge of ports...) That's GREAT for material removal.

 

Thanks sonix! Do you do the bowl work, shaping the valve guides bosses, etc through the valve pocket itself?

 

Yes, that's how I did it. A little bit through the port, but that's a lot harder.
A 3/8" cylinder with ball end (or 5/16") works good for that.