Making tapered headpipes

[Jimroid]

Parallel headpipes do not make max power and cone sections are tedious. I cut a narrow sliver out, and starting at the small end of slit, gradually pinched it together with 3 hose clamps. I welded [tig] in short 1/2" to 3/4' increments gradually drawing together and welding. It works better with short movements. I used 16 gauge,but 18 gauge would of course be easier.I used a nut driver for speed and a 1/4" ratchet for torque.Use all three clamps in an even and back and forth pattern.Don't get too aggressive,you will strip the hose clamps and start a ripple in the headpipe.My second pipe turned out better than the first as I learned quite a bit from the first one.

[dgoodsy]

This is a great idea, thanks for sharing!

I assume you had a known diameter of pipe at the head that you were targeting and used the circumference to figure out how wide the cut out vee should be at that end of the pipe? Then drew a straight line down to the point where the 2 sides of the vee converge? I'm just trying to figure out the process here..

[Jimroid]

Exactly. I used a paper template from my dimensions,taped the template in place,marked with a black marker, and cut with a jigsaw. It was very easy to cut.

[ChrisK]

Nice work Jim!

[Blokhead]

Good idea. How much did the radius increase?

[Jimroid]

That is a great question. The 6" radius stayed a 6" radius.

[johnu]

Nice work Jim I am definitely going to try this on my next set of pipes, not sure I can make as good of a job as you did but it's worth a try Was this your own idea Jim? Hard to believe I haven't seen this before seeing how much research I've done with regard to build expansions!

[Jimroid]

Yes,I came up with this one on my own. I thought it through a few times and just couldn't see a reason not to try it.