Maney Exhaust Header Blow Out

Has anyone had anything like this happen to their Maney exhaust? This happened during the BEARS race at Willow Springs a couple of weeks ago. At first I thought the header nut had come loose but really couldn't look on the track-black pipe inside a black fairing.... When I pulled into the pit I was quite surprised to find the right exhaust peeled open like a can of sardines. Was able to get it welded at the track and make the two races Sunday but a crack formed in the middle of the patch at some time during the last race. Due to the tight angle I'm thinking the best way to repair is to buy and exhaust doughnut and cut/braze into place. Any better ideas?

Tom Kullen
AHRMA 44x


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Now thats a picture of sNorton power pulses! Never saw a section pop out.

No Maney headers here as made my own 2-1 and they fracture like any other Cdo header at the 1st bend or just outside the exhaust ring, and in my case also at the Y junction. A simple sealing patch is just a band aid, my solution so far is weld more robust ~1/4" thick steel plate to straddle the fracture and brace pipe across bends. Held up after that even off road rough riding but looks ughly as sin so insulation wrap will cover up the snickers behind my back. Don't take much scraps to tack on here and there to save 2-1 headers function on the cheap or expedient.

I'd email Steve and ask if yours is a one in a row or something he's had to deal with
and how.

I suspect you were going too fast. Slow down and enjoy the scenery... :mrgreen:

What does the exhaust mount to on the other side? If it's to the frame, is there a way to mount it to the cradle?

Never seen this before but , could it be the gauge of the original tubes being what it is ,that is thin ,that by stretching (bending ) it becomes almost too thin and gave way because of fatigue ?
On our norton outfit we ran a 2 into 1 with the RH side running a similar bend as on Maneys , and in the dark that side always glowed red . the other side never did but that had a MUCH wider angle because the 2 headers came together on the sidecar platform (incidentely they also went through the fueltank )
we thought of something mechanicly (ignition ,carburation etc)but it was just the shape of the bend wich caused it
of course we used thicker tubes than Steve because we had to bend it ourself but i believe that that will be the cause,too much stretch ,heat and old age (although that is relative)

Wow! I've never seen a break like that before. I'd guess it has to be vibration. It looks like you're running a standard chassis, so it's still got Isolastics ? How is the exhaust mounted to the frame? Is there plenty of rubber mount to absorb the vibration?

Second question: How well does a 2:1 exhaust work? I had one that gave a great big mid-range flat spot so I went back to 2:2 with Supertrapps

My Husaberg did something very similar (although stainless), it looks like the steel is burnt, maybe it carburises because of the heat and carbon in the exhaust gas and just crumbles. It was almost impossible to weld so I cut out the section and welded a stainless short radius dairy/deco elbow in

That pipe has failed due to running at red hot temperatures, and the fact that the tubing is probably going to be a little thinner in the area of the bend. You will need to replace the damaged pipe, and might find that you need thicker gauge tubing to prevent future problems.

I will add my 2 cents worth. I agree with the guy from Belgium. I think it is heat cycles that is causing the fracture problem. If you rev your Norton equiped with a Maney exhaust at a standstill you will notice the right header pipe glow red hot. No air flow to cool it. It happened to my bike when I was setting the ignition timing & it scared the cr@p out of me. I'm sure a fairing adds to the problem.

Great pic. It shows how much power Nortons make.

Carbonfibre said:

That pipe has failed due to running at red hot temperatures, and the fact that the tubing is probably going to be a little thinner in the area of the bend. You will need to replace the damaged pipe, and might find that you need thicker gauge tubing to prevent future problems.

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Tight bends with thin wall tubes produce stretch fractures between the "pulled" area's, these thinned area's can be supported by wrapping 2mm mild steel wire tightly around the bends, [ a small tig weld at wire ends keeps it in place]

My first bike was a Norton P11 kind of all pieced togeather and it had a home made exhaust that would glow bright red. Scared me too but my pal's all liked it! In my case it was crapp tube but in your case it must be that your such a "hot" rider!

The pipes on my hard-ridden Commando streetbike used to crack apart right there too, and I did the same thing, whip out the torch and weld them up with a coat-hanger while it was on the bike. Never had a weld re-crack.
With the Commando engine/tranny jumping around and the exhaust tied to the chassis it is going to flex somewhere, combined with heating and cooling it is a tough world for a thin-wall tube.

beng said:

The pipes on my hard-ridden Commando streetbike used to crack apart right there too, and I did the same thing, whip out the torch and weld them up with a coat-hanger while it was on the bike. Never had a weld re-crack.
With the Commando engine/tranny jumping around and the exhaust tied to the chassis it is going to flex somewhere, combined with heating and cooling it is a tough world for a thin-wall tube.

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I think we are talking about 2 completely different things here
A racing bike CANNOT be compared with a even very fast ridden street bike
Take you street bike to a race track and hammer it for 20 minutes ,3 times a day ,for 3 days and see for yourself .But you must try to keep up with those bikes you think are slow when standing at the side
If not repeat a few times.....

A commando cracks its pipes there if there is something wrong with those rubbers at the rear (exhaust mountings) or if your front iso are badly adjusted ( too soft rubbers do not help either)