11 replies to this topic

[mcman56]

I have a nice dent in the lowest part of my 2.9 header pipe. Pics are below. This has to be a pretty common dent area. Does anyone have experience fixing something like this?

Searching the internet, I find two fix methods. Some great results are shown for freezing water in 4 stroke header pipes. However, this pipe section is somewhat oval and there is a seam that could get pulled apart. Then there is the pressurize with air and heat method. It sounds feasible and more controllable than freezing water but may have risks with names like bomb and cannon.


http://i103.photobucket.com/albums/m137/mc...rco_pipe009.jpg
http://i103.photobucket.com/albums/m137/mc...rco_pipe008.jpg
http://i103.photobucket.com/albums/m137/mc...rco_pipe007.jpg
http://i103.photobucket.com/albums/m137/mc...rco_pipe006.jpg

[ishy]

I had a dent in my 4t header pipe and was able to get it out by tapping around the outside of the dent with a small hammer, takes a while but it did lift the dent out.

[max1956bikes]

i have done loads of them at bike shop i used to work at.we used to heat up until red hot, pressureise with air,and dent pops out.

[ZIPPY]

I had mashed my header pretty good, the walls were close to touching and it had split. I took a somewhat extreme route and used a Dremel moto-tool with the cutting disk and cut out the dented portion and the beat it back out to a roundish shape (never gonna get it perfect) and welded it back together.

Although it is worth mentioning that prior to this repair I convinced my wonderfully understanding wife that I needed a new one so I could compete within the next couple weeks. And then in my spare time did the fix so now I have a spare for when I crash and dent the new one. (notice it says "when" not "if" )

[mcman56]

MAX1956BIKES
How much air pressure did you put in the pipes?

[Neo]

mcman56, on Dec 16 2007, 01:06 AM, said:

MAX1956BIKES
How much air pressure did you put in the pipes?

Please tell us??

And what's the best way to close/seal-up the pipe ends?


Best of balance.

Neo

[ZIPPY]

Quote

Neo Posted Today, 06:19 PM
QUOTE (mcman56 @ Dec 16 2007, 01:06 AM)
MAX1956BIKES
How much air pressure did you put in the pipes?

Please tell us??

And what's the best way to close/seal-up the pipe ends?


Best of balance.

Neo

The handyman's secret weapon..........................DUCT TAPE!?!?!?

[copemech]

You must understand that this "heat" method is totally unapproved and experimental, will result in the pipe still looking like s%4T, and may be dangerous to perform, even by experienced folk!

If your pipe is not caved in more than halfway, you will probably notice no difference anyway! If you want it right, get a new one!

For those who have nothing better to do, rubber plugs are available at the hardware store, good luck! Drink more beer!

[copemech]

mcman56, on Dec 15 2007, 12:06 PM, said:

MAX1956BIKES
How much air pressure did you put in the pipes?

Whatever it takes!

[mcman56]

I made a bolt on plug for the engine side. It was over kill but I also added a 75 psi pressure relief valve. On the muffler end, I used an automotive rubber expanding freeze plug. To keep it from getting pushed out, I trapped the pipe in sort of a wood sandwich. (This was one of those activities that took on its own life.) Mapp gas heated it red hot and a small hammer was used to tap around the dent. It took some time but came out. The result looks a little lumpy but I'm not a great freehand craftsman. The pressure was right at 75 psi because the valve popped a few times. Next time I would try more pressure.

before
http://i103.photobucket.com/albums/m137/mc...er/DSC00391.jpg

after
http://i103.photobucket.com/albums/m137/mc...er/DSC00402.jpg
http://i103.photobucket.com/albums/m137/mc...er/DSC00397.jpg

set up
http://i103.photobucket.com/albums/m137/mc...er/DSC00393.jpg
http://i103.photobucket.com/albums/m137/mc...er/DSC00394.jpg
http://i103.photobucket.com/albums/m137/mc...er/DSC00396.jpg

[copemech]

Gee, it worked!

Tell us the toll in man hours and goods!

Maybe you can rent that thing out!

[mcman56]

Mostly it is made of surplus junk from the garage but I spent about $20. I'm sure it took over three hours to fab all of the fixturing so it is not a cost effective use of time. I could not find a local shop that did this type of work and did not want to spend time shipping. I also wanted to see how it would work. It is surprising what some people will do to amuse themselves.