(engine) exhaust mounting hardware - flared adapter for header pipe - ???

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on my 74 Mk2 header pipe (engine side) - the end is flared (35-45° - ???). part of the mounting hardware is a flared adapter ring that mates to the flared end of the pipe and the other side, a flat end that mates to the sealing ring/washer. the rest is the standard split collet/exhaust nut. question - I don't see the flared adapter ring in the parts book. so not original? missing from the parts book? a Mk3 or Mk2a feature? or what? does the flared adapter replace the sealing washer? i'm thinking I have too few threads engaging on the finned exhaust nuts to cylinder head. too many parts? little confused. this is the way the bike was assembled when I bought it, although can't trust the previous assembled configuration. TIA....

i'd post a pic, but don't have the pipes off the bike just yet.
 

L.A.B.

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part of the mounting hardware is a flared adapter ring that mates to the flared end of the pipe and the other side, a flat end that mates to the sealing ring/washer.
The sealing washer is not used with the spherical seating and flared pipes.
https://andover-norton.co.uk/en/shop-details/16482/ex-pipe-spherical-seating

the rest is the standard split collet/exhaust nut. question - I don't see the flared adapter ring in the parts book. so not original? missing from the parts book, a Mk3 or Mk2a feature,
Although supposedly Mk3, that type of flared exhaust pipe was introduced on the Mk2A.

The flared pipes (065256 & 065257 same as 850 Mk3) are listed in the Mk2/2A supplement for Mk2A but the spherical seatings and spherical collets (065259 & 065260) appear to have been left out.

https://andover-norton.co.uk/en/shop-details/20631/exhaust-pipes-pair-850mk3-balanced
 

Tornado

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Interesting. My MKII did not have the spherical seating washers, just the short rose nuts, collets and copper sealing rings. This was on the balance-pipe headers when I removed to replace with un-balanced headers after finding the left side "branch" cracked (as is typical). What is the purpose of the spherical seats and are the pipe flanges a different shape for their use?
 

Tornado

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OP: If the un-balanced headers you're planning to substitute in do not have the flared ends, then leave out the spherical seating rings and the collets, and use two sealing washers (the steel type since these compress less) per header pipe if you want to keep using the shorter rose nuts (or buy the longer/earlier (prior to MKII) thread type).
 
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The sealing washer is not used with the spherical seating and flared pipes.
https://andover-norton.co.uk/en/shop-details/16482/ex-pipe-spherical-seating



Although supposedly Mk3, that type of flared exhaust pipe was introduced on the Mk2A.

The flared pipes (065256 & 065257 same as 850 Mk3) are listed in the Mk2/2A supplement for Mk2A but the spherical seatings and spherical collets (065259 & 065260) appear to have been left out.

https://andover-norton.co.uk/en/shop-details/20631/exhaust-pipes-pair-850mk3-balanced
that clears up many things. seems somewhere along the line, someone added the sealing washer in with the spherical seal. most likely the reason why the finned exhaust nuts are not threading in all the way. BTW, you are a wealth of information! thanks....
 
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maylar

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I found out the hard way that the short 850 nuts don't work with 750 pipes, they bottom out. You can double up on the crush washers, but I found longer ones on eBay somewhere in the same style.
 

Tornado

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I found out the hard way that the short 850 nuts don't work with 750 pipes, they bottom out. You can double up on the crush washers, but I found longer ones on eBay somewhere in the same style.
Yes I wanted to use longer roses but when I went to fit them I discovered a DPO had machined the head to take not only oversized diameter roses but also lefthand threaded!! So mine are basically custom Unobtanium.
 

maylar

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Yes I wanted to use longer roses but when I went to fit them I discovered a DPO had machined the head to take not only oversized diameter roses but also lefthand threaded!! So mine are basically custom Unobtanium.
That's just... wrong.
So, are you lining up for one of Fullauto's heads? ;)
 

olympus

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The sealing washer is not used with the spherical seating and flared pipes.
https://andover-norton.co.uk/en/shop-details/16482/ex-pipe-spherical-seating



Although supposedly Mk3, that type of flared exhaust pipe was introduced on the Mk2A.

The flared pipes (065256 & 065257 same as 850 Mk3) are listed in the Mk2/2A supplement for Mk2A but the spherical seatings and spherical collets (065259 & 065260) appear to have been left out.

https://andover-norton.co.uk/en/shop-details/20631/exhaust-pipes-pair-850mk3-balanced
Are these spherical collars fitted tapered face to head or down pipe??
 

L.A.B.

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Are these spherical collars fitted tapered face to head or down pipe??
Taper (spherical side) to the pipe. Edit: Assuming "collar" refers to the spherical seating and not 'collets' which can only fit one way.
 

Ron L

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OP: If the un-balanced headers you're planning to substitute in do not have the flared ends, then leave out the spherical seating rings and the collets, and use two sealing washers (the steel type since these compress less) per header pipe if you want to keep using the shorter rose nuts (or buy the longer/earlier (prior to MKII) thread type).
I have always used the collets from the '73-'74 850 (06-3990) along with the sealing washers with the 850 nuts for non-balanced flanged pipes. Or just the sealing washers with 750 nuts.
 

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