Exaust gasket ?
- Thread starter The yaki
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Is this for a Mk3?
The Mk3 doesn't use a gasket but has a spherical seating (below) in which case the flat side goes to the head.
https://andover-norton.co.uk/en/shop-details-2/16482/exhaust-pipe-spherical-seating
Do your unbalanced pipes have the Mk3 type flared ends so the flares fit against the spherical side of the seatings?
The Mk3 doesn't use a gasket but has a spherical seating (below) in which case the flat side goes to the head.
https://andover-norton.co.uk/en/shop-details-2/16482/exhaust-pipe-spherical-seating
Do your unbalanced pipes have the Mk3 type flared ends so the flares fit against the spherical side of the seatings?
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It all depends on which type of head fitting the pipes have?
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Are they new pipes or have they already been fitted as the Mk3 generally needs a longer pipe on the left side to clear the Mk3 primary case. I'm assuming they are for a Mk3, if not then you need to say which model it is as the head fitting can be different.
The information on the AN webpage that non balanced pipes need gaskets is incorrect as there are non balanced pipes with the correct Mk3 flared ends (see feked picture above), so they should really make that clearer or remove it. There are three different pipe head fittings so we need to know what you have?
https://andover-norton.co.uk/en/shop-drawing/147/exhausts-mufflers-passenger-footpegs
The information on the AN webpage that non balanced pipes need gaskets is incorrect as there are non balanced pipes with the correct Mk3 flared ends (see feked picture above), so they should really make that clearer or remove it. There are three different pipe head fittings so we need to know what you have?
https://andover-norton.co.uk/en/shop-drawing/147/exhausts-mufflers-passenger-footpegs
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robs ss
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If you have those, then I would fit the flat side against the head - you don't want to dimple and damage that surface!
The steel headers can look after themselves.
Cheers
PS: Same story, flat to head, with 06-5259, although it requires the collet too (06-5260)
Cheers
The yaki
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They are old pipes. Flat end not flared . The head seating is the same . The pipes are probably 20 years old and have been fine with single washer but have slackened off "understandably " with vibration assumably ! I just thought possibly there was a right and wrong way round ro fit the gasket . Can't find anything in manuals. Flat side to head sounds plausible? Roy.
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I always put the flat side to the head because I figure it's going to be a flat machined surface where the pipe is more likely to be off having been formed. For extra sealing you can coat them in high heat silicone and let them dry fully before installation which is a good bodge for reusing them as well.
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Flat side to the softer metal which is the head, check that you do not have the original MK3 short exhaust nuts as they will bottom out before the exhaust is gripped properly and may be the cause of your nuts loosening off.
Short
Long, needed with non mk3 pipes fitted to mk3
Short
Long, needed with non mk3 pipes fitted to mk3
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I certainly appreciate JC doing the thermal expansion exercise to debunk the excessive expansion as a major factor of nut fit.
Knowing what the head does thermally would help further show the relationship between them.
The test I had done quite a while ago consisted on the actual measurement of pitch diameter using the engineering 3 wire method .
That was certainly eye opening with numbers all over the map.
For info there are 3 norton exhaust nuts.
The basic 3/4" deep small fin 1949-1972 Though they were carried under evolving part #
One year 1973-750 Big fin 3/4" deep threads
850...
Knowing what the head does thermally would help further show the relationship between them.
The test I had done quite a while ago consisted on the actual measurement of pitch diameter using the engineering 3 wire method .
That was certainly eye opening with numbers all over the map.
For info there are 3 norton exhaust nuts.
The basic 3/4" deep small fin 1949-1972 Though they were carried under evolving part #
One year 1973-750 Big fin 3/4" deep threads
850...
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- May 7, 2005
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- 7,609
The current short AN looks to be longer than the originals (the photo linked is the current AN MK3 offering), I have some old ones and they look shorter and the threaded section is 0.6" long.
Also note the long Feked one has a reduced section lead in so it can go further in than the threads go into the head recess.
The yaki
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. Roy
robs ss
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Rather than start a new thread (pardon the pun!)...
My 850 Mk2A has an unbalanced system with peashooters but is restrained with these...
On one side the collets are intact (one-piece) whereas the other side has fractured (now two pieces).
My question is, given the frail nature of these collet assemblies, are they intended to fracture into two pieces?
My 850 Mk2A has an unbalanced system with peashooters but is restrained with these...
On one side the collets are intact (one-piece) whereas the other side has fractured (now two pieces).
My question is, given the frail nature of these collet assemblies, are they intended to fracture into two pieces?
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I don't know if it is intended but that's what often happens.
