Header Pipe Not Secure

Tornado

Tornado

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While checking over carbs to fix a sooty left side sparkplug, discovered left side header not hold tight at rose nut to head. These are pre-balance pipe headers with a flange and I've fitted the longer type rose nuts. Head has a alu-bronze thread sleeve that is in place and very solid. No matter how tight I make the rose, the header still rocks side to side. Tried either steel or copper exhaust crush seals, no difference. There is enough movement to permit the header to rattle against the side stand nut or tang at certain lower rpm.

Any ideas what to check? Thinking to try wrapping copper wire around pipe flange to help nut compress more evenly...
 
Tornado said:
While checking over carbs to fix a sooty left side sparkplug, discovered left side header not hold tight at rose nut to head. These are pre-balance pipe headers with a flange and I've fitted the longer type rose nuts. Head has a alu-bronze thread sleeve that is in place and very solid. No matter how tight I make the rose, the header still rocks side to side. Tried either steel or copper exhaust crush seals, no difference. There is enough movement to permit the header to rattle against the side stand nut or tang at certain lower rpm.

Any ideas what to check? Thinking to try wrapping copper wire around pipe flange to help nut compress more evenly...
Click to expand...
Use TWO gaskets.

The rose isn't shouldered in is it?

"Rattle rings" deleted, correct?

Pictures please

Council against copper wire, it'll jam INSIDE the nut.

If run loose, and you didn't notice it, could have worn the seal washer/gasket INTO the aluminum head.

Does the rose go ALL THE WAY with no pipe? Carbon in the threads?
 
Last edited:
Tornado said:
Thinking to try wrapping copper wire around pipe flange to help nut compress more evenly...
Click to expand...

Or, replace the crush washer with the spherical seating.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
 
What type of flange. If it is the Mk 3 flair type, it is designed to use the spherical fittings with collets.
Flair type.
andover-norton.co.uk

Andover Norton - EXHAUST PIPES (PAIR) 850MK3 BALANCED - 06.5256/7

EXHAUST PIPES (PAIR) 850MK3 BALANCED
andover-norton.co.uk
Non Flair type.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
 
The pipes are 90 degree flanged, flat, not hemispherical. I'd assumed they are from an earlier pre-balance pipe setup (perhaps 750; I got them from a local guy used). Righthand side is held solid and fine.
The roses are not fully threaded in to surface of head, still see threads. Yes the lockring is removed. Without the header/crush washer, rose nut goes in much further until barely any thread visible. So that says it should apply a good loading to the header flange. It seems like the flange is not sitting square when torqued down, letting the flange flop a bit against the fully home rose nut.
 
Tornado said:
The pipes are 90 degree flanged, flat, not hemispherical. I'd assumed they are from an earlier pre-balance pipe setup (perhaps 750; I got them from a local guy used). Righthand side is held solid and fine.
The roses are not fully threaded in to surface of head, still see threads. Yes the lockring is removed. Without the header/crush washer, rose nut goes in much further until barely any thread visible. So that says it should apply a good loading to the header flange. It seems like the flange is not sitting square when torqued down, letting the flange flop a bit against the fully home rose nut.
Click to expand...
Possibly the head was cut deeper and maybe not squarely when the insert was installed or at some point the pipe was loose and dug out some of the aluminum in the head - I recently had on that way on one side of the seat. In a perfect world, that seat would be recut. As others have suggested, try two sealing washers.
 
Couple of picks with single copper crush seal, no rattle ring, nut as tight as possible with waling on end of the big steel rose C spanner and sledge. Pipe still rocks like this.
Header Pipe Not Secure
Header Pipe Not Secure
 
I've jammed a bit of hard rubber hose btwn pipe and sidestand nut to stop the rattles for now. Will source some spherical crush seals.
 
Tornado said:
The pipes are 90 degree flanged, flat, not hemispherical. I'd assumed they are from an earlier pre-balance pipe setup (perhaps 750; I got them from a local guy used).
Click to expand...

Yes, if the lockrings only fit onto the pipes from the silencer end and not over the flange then they are '750' pipes so use 'long' 750 lockrings .

Tornado said:
It seems like the flange is not sitting square when torqued down, letting the flange flop a bit against the fully home rose nut.
Click to expand...

It's not unknown for the pipe seating face inside the port to be out of alignment so the pipe flange (or pipe flange out of alignment with the head) doesn't pull together uniformly even with the crush washer between them.

Tornado said:
Will source some spherical crush seals.
Click to expand...

The spherical seatings are not "crush" seals and although intended to be used with flared pipes it is possible that the spherical seating will allow for the apparent misalignment between the pipe flange and exhaust port.
 
Hopefully the spherical seal will solve it, or multiple crush washers.
A few questions out of interest.
1. Is the thread depth the same on both roses? It appears to be an AN, I would expect it to be correct.
2. Is the welded part of the flange the same on both pipes? Maybe the offending pipe is too shallow.
If these check out, then it's the Head.
 
I use spherical seats with pre balanced pipe pipes and the standard length nuts, you get a couple of extra threads showing but it clamps up well. Before the final tightening you get more chance to adjust the pipe orientation.
 
kommando said:
I use spherical seats with pre balanced pipe pipes and the standard length nuts, you get a couple of extra threads showing but it clamps up well. Before the final tightening you get more chance to adjust the pipe orientation.
Click to expand...

Perhaps the spherical seating would work better (with flanged end pipes) if reversed, with the flat face of the seating against the pipe flange and the spherical face against the head?
 
L.A.B. said:
Perhaps the spherical seating would work better (with flanged end pipes) if reversed, with the flat face of the seating against the pipe flange and the spherical face against the head?
Click to expand...
Never tried that but then the ability to adjust the pipe angle would be gone, found this very useful on the timing side to get good clearance between kickstart and pipe.
 
I had a similar situation but reversed, right side header was loose. Two washers solved the problem. A quick fix. Hopefully, the solution to your issue is as simple.
 
Like Wem said two copper washers will do the trick. I have had the same problem, double the washers, QUICK FIX!!!
 
I'll give two coppers a go. Only have one copper and two steel to play with until I remove the good fitting right side pipe which has my other copper washer.
 

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