Modifying stock iron intake manifold

Any suggest on where to get some double butts and what head shape works best? AKA rotary file.

 

McMaster Carr. Flame shape. 3/8.

 

Thank you, the price doesn't seem to bad. Not to split hairs but they have 1/2" and 5/16" diameter flame heads.

 

1/2

 

Should have 3/8?

 

Making progress. It wasn’t too bad so far.

I really appreciate all the help on this project.

It was really good to start with the intake manifold. I feel that the burrs and electric die grinder are pretty easy to use. I also brought a rheostat for speed control, as the electric die grinder was fixed at 25,000 rpm.

 

Looks good

 

Thanks Ethan.

How are you guys cleaning out all the shavings after you are done? I made the mistake of painting it already.

 

Compressed air

 

So that you know for "next time", a rounded-but-blunt edge on the divider would be preferable to a "sharp" edge.

Remember that the pointy edge of a raindrop is on the downwind side, and the fat, blunt end is what moves the air aside.

 

I did grind it to a sharp edge then ground the sharp tip to a small dull and round edge, not big and round. The picture looks like the edge is very sharp but it has a small round on it. I didn’t see a lot of value in making a raindrop or airplane wing, so to speak. It sounds like the main objectives are to create more volume in this chamber and to allow each side to share the fuel air mixture. So like any entrance, having a smooth transition laterally makes sense. I also read where completely removing it made things worse, so there has to be some reason it needs to still be in there. At that point, I figured I was splitting hairs and that some divider without very sharp edges was good enough.