Repairing crushed header / building a pipe

This is a repost of something I was working on on a different site. More people hang out here so maybe it will benefit someone. Here goes...

In had been looking for a new exhaust to replace my old Yosh which is a bit beat up - the primaries are crushed in front of the collector, which is very common for these pipes. I was looking for a header with nice soft bends, like the old hand bent Yosh or Moriwaki systems.

Found a header on Ebay that had a junk tailpipe but nice primaries, but the seller removed the listing "because he found a small rust spot in the muffler end". Well, no problem since I was going to hack that ugly thing off anyway. He said the rest of the pipe was solid... Since he was honest enough to remove the listing, I figured what the hell...
We struck a deal, I paid and when I got the pipe, it was a complete piece of junk... The primaries were crushed in front of the collector (no better than my Yosh), a big dent in one of the headers, pinholes and cracks where the primaries enter the collector. The pipe had a number of very coarse repairs with about a half pound of bronze but I could still see daylight in several places looking down the collector.

To be fair to the seller, I never complained or even contacted him. No hard feelings really. I would have never sold the pipe like this myself, but... this is a risk of doing internet deals, sooooo.... Let's see if I can fix it!

After all, I like the shape of the headers and I've never tried fixing a crushed or dented exhaust before. It will mean cutting off the primaries at the collector. If I can get the dents out, I'll have to buy a new collector, weld it all back together and make my own tail pipe...

Piece of junk:

wow dutch, that is a junk pipe. It reminds me of a basanni pipe i got off e-bay. Same deal, the seller said it was a good pipe and just needed repainted. Come to find out, the pipe looked like the bike was laid down because it had alot of brazzing done on the muffler part and wasn't round anymore either, needless to say i sanded it down and repainted it, ran it for a season and traded it to another member here..........god i wish i still had that pipe.......it sounded so sweet. Let me see if i can find a pic of it mounted on my z1.

here are some pics

another

and a shot of the back. Maby i will find another basani one day, or even a yoshi. The bassanni was a butt ugly pipe but the sound was killer.

Yeah the Bassanis are maybe not the prettiest, but they are supposed to work really well.
Never mind the ugly endcan I didn't even care. ore worried about the damage to the primaries. Here's a picture of the bottom - still can't really tell much from these pictures.

It is much uglier up close.

First step: I cut off the two bottom primaries and used a pipe expander to un-crush them. This tool is cool and dirt cheap!

To my surprise, it actually worked really well. You just shove it in the pipe and crank on the bolt to expand it. Worked it back and forth patiently and voila, the crushed primaries are round again. This thing only works on a straight pipe.

The quarter-sized dent is in the bend of the primary so I will have to try something else for that one.

find a ball bearing that is just abit smaller than the inside diameter braze a chunk of wire rope to it and then pull it down to the crushed part of the pipe then heat the pipe up until it is red hot at the crushed part then pull the bearing thru it repeat on the next headers it will work very well keep the pipe red hot while your doing it.

Pipe expander

ya for what that bassani lacked in looks it made up big time in power. A pipe extender you say? Hmmmmm that sounds like a tool that will find its way into my tool box, i have passed up countless pipes because of the dented primary pipes. Can't wait to see the pics......look's like you got this in the bag.

Feast yer eyeballs...

a pipe expander works good on the collector end but they would be next to impossible to get inside the primary tube even if you could find one that came in a small enough size