I was riding down a sandy and rocky road today when my tire pushed the front of a rock down into the sand causing the back to pop up and crush one of my header tubes.I planning on riding this weekend so I pulled the pipes and separated the header.I rounded of the ends of several sizes of metal rods to use as tools to reach inside the header and pound out the dent.I made good progress but I could see that I would end up with a crease protruding in to the header.I decided to keep pounding untill the metal tore.
After I punched through I heated it with a torch and straightened out all the wrinkles and bent the tube back to round.then tapped the metal pieces back in place and welded up the cracks.Its pretty ugly but the inside volume is about the same as before I crushed it.I' ll probably buy a new set up eventually that I don't have to remove for oil changes,but I can keep riding.
That's ugly. I love it.
My next project should be a skid plate to fit in place of the chin fairing.I bet Noel already has one.
The FJ is known to bottom out on the square tubed aftermarket headers. Can't say as I have seen a hole like that though. I think another owner collapsed a head pipe during an off road excursion.
Looking at your photos, does the #3 pipe have 2 small holes??
Fred
No Fred those are shadows cast by two leaf fragments.I finished fixing them around 2:00 am and took the picture under an overhead light.The headers are made of thick metal.After using half a coat hanger to repair the crushed tube I think it will now support the entire weight of the bike .The inside view of the repaired tube looks much better than the outside
your torque went up
Nice work mate :good2:
For those who are into welding (not me I'm shit at it :blush:), many older headers are made of 445M2 stainless. Many aftermarket are 304 stainless.
If you're using TIG and filler wire, my welder mates suggested matching the filler wire to the base metal (same for MIG).
Troyskie
I had the same deep dents in my 4 into 1 headers. I securely plugged both ends and filled the pipes with water to the brim, then stuck the pipes in the freezer. It only took a few hours for the dents to completely smooth out.
That's an awesome idea.
Joe
Quote from: Miker on October 10, 2019, 06:14:18 PM
I had the same deep dents in my 4 into 1 headers. I securely plugged both ends and filled the pipes with water to the brim, then stuck the pipes in the freezer. It only took a few hours for the dents to completely smooth out.
. You probably don't have a before picture but post an after picture.you must have a large freezer.did it expand your pipes in the undented areas?How did you plug the ends?
I tried that on a CB750 header tube 40 years ago and it did not work.
The frozen water kept pushing the plugs out.
(https://m.grainger.com/rp/s/is/image/Grainger/2HCF1_AS01?$smmain$)
If I could have welded caps on the ends, that might have worked but the pipe had a seam in it I would be worried about splitting.
Mike, before I throw the BS flag, what kind of plugs did you use?
Quote from: T Legg on October 10, 2019, 08:02:10 PM
Quote from: Miker on October 10, 2019, 06:14:18 PM
I had the same deep dents in my 4 into 1 headers. I securely plugged both ends and filled the pipes with water to the brim, then stuck the pipes in the freezer. It only took a few hours for the dents to completely smooth out.
. You probably don't have a before picture but post an after picture.you must have a large freezer.did it expand your pipes in the undented areas?How did you plug the ends?
No I don't have before pics, but my dent was as bad as the one above. I attached a couple after pics. The circled discolored area on the pipe on the right is where the bad dent was. I initially tried to pop it with propane and dry ice before I found this video (there are several vids like it): https://www.youtube.com/watch?v=HhWzxYLG9sM. (https://www.youtube.com/watch?v=HhWzxYLG9sM.) The pipe on the left was also dented pretty bad and I recently put a new dent in it (who knows how).
I did exactly as recommended in the vid and took the pipes to home depot where I found the rubber plugs for the individual headers. I don't recall the size I used and I can't remember where I put them You'll want to get plugs that fit in the headers at least half way by hand. You will then pound them in as much as possible with a rubber mallet.
The merge collector is a bit trickier as it is a large hole. I cut a hot water bottle in half and slid it over the merge collector end. Then, I used a hose clamp like the one in the picture and tightened it down as much as possible. You could also use baling wire. That worked really well, but it is important to keep that end up and the headers down in the freezer as the plugs at the headers proved to be more water tight than the hose clamped merge collector.
No the process will not expand the undamaged pipes at all, though I would recommend checking on its progress as often as possible and take it out when it's done. I don't have a large freezer, but neighbor has one in his garage.
I used a propane torch to dry the pipes immediately after I took them out of the freezer.
Quote from: Pat Conlon on October 10, 2019, 10:02:26 PM
I tried that on a CB750 header tube 40 years ago and it did not work.
Mike, before I throw the BS flag, what kind of plugs did you use?
Yea I remember when there was no internet to solve all our problems. Seems like a lifetime ago.
That header looks pretty good.If not for the discoloration (that I assume occurred in your dry ice attempt)it would be hard to tell you worked on it.much cleaner looking than my pound and weld method.
Quote from: T Legg on October 10, 2019, 11:28:31 PM
That header looks pretty good.If not for the discoloration (that I assume occurred in your dry ice attempt)it would be hard to tell you worked on it.much cleaner looking than my pound and weld method.
Yea I burned the hell out of it with the torch. The heat and dry ice didn't work at all.
Thanks Mike!
I have seen the results of fulling pipes with water and freezing them but outside in the winter. They were expansion chambers for 2 stroke. Worked well. It would be harder with the 4 stroke header pipes.
Quote from: Pat Conlon on October 10, 2019, 10:02:26 PM
Mike, before I throw the BS flag, what kind of plugs did you use?
I'm also struggling with the idea of what you could plug the ends with that would withstand a greater force than that required to push out a dent, particularly a dent on a heavy gauge SS small diameter pipe on a bend.
Noel
Quote from: ribbert on October 11, 2019, 08:21:38 AM
Quote from: Pat Conlon on October 10, 2019, 10:02:26 PM
Mike, before I throw the BS flag, what kind of plugs did you use?
I'm also struggling with the idea of what you could plug the ends with that would withstand a greater force than that required to push out a dent, particularly a dent on a heavy gauge SS small diameter pipe on a bend.
Noel
I was surprised how well it worked.
A discussion on exactly how water freezes and expands under pressure when cooled to zero degrees Fahrenheit is probably better left to articles written by scientists who study the topic.
Watch the vid in my previous response and/or run a search and find the other vids on the topic. That also appears to be a heavy gauge four stroke header in the vid; not a thin wall two stroke. Worked on both our applications. You could also grab a length of 18 gauge stainless, dent it, and experiment.