EXHAUST PIPES S TYPE (PAIR)

NOTES ON THE COMMANDO SS AND S TYPE EXHAUST PIPES - EPNS & EPNCSS

THE END PIECE ON THESE PIPES, THE BIT THAT ENTERS THE CYLINDER HEAD IS BY DESIGN ATTACHED AT QUITE AN ACUTE ANGLE.  THIS CAN PRESENT AN OBSTRUCTION TO THE ROSE NUTS WHERE THEY CANNOT PASS OVER THE LARGER DIAMETER CREATED BY THE ANGLE CHANGE.  ON CHECKING TWO PAIRS OF SS PIPES WITH ABOUT 20 OR SO ASSORTED ROSES I FOUND AS FOLLOWS:

PIPE 1 - RIGHTHAND
PIPE 2 - LEFTHAND
PIPE 3 - RIGHTHAND
PIPE 4 - LEFTHAND

ASSORTED RGM ROSES, 750, 850 BRASS, PLATED, ALLOY AND STAINLESS.  ALL FITTED PIPES 1 AND 2.  PIPE 3, ONE 850 FAILED TO FIT BUT COULD PERHAPS HAVE BEEN FORCED ON.  PIPE 4, ALL 750 FITTED, ALL 850 FAILED TO FIT.

GENUINE ORIGINAL POST 1962 NORTON ROSE FITTED ALL 4 PIPES.

AN ASSORTMENT OF ROSES CONSISTING OF 3x 850, 2x PRE 1962 ORIGINALS AND ONE OLD BRASS ALL FAILED TO FIT ALTHOUGH ON OCCASION THEY COULD HAVE BEEN FORCED OVER.

IN CONCLUSION I WOULD SAY THAT THERE WILL BE A LARGE VARIATION IN THE BORE OF ROSES AS IT IS ONLY A CRITICAL DIMENSION WHEN USED WITH THESE (RARE) PIPES AND MANY MANY SMALL BATCHES OF ROSES HAVE BEEN PRODUCED SINCE THE FACTORY CLOSED IN 1977, THAT IS WHY WE HAVE DRAWN AND PRODUCED OUR OWN ROSE.  850 ROSES SEEM TO BE THE WORSE CULPRITS, PERHAPS NOT SURPRISING AS THESE PIPES WHERE NOT USED ON THE 850.  THE PROBLEM IS NOT INSURMOUNTABLE YOU COULD PURCHASE A PAIR OF OUR ROSES 062464, 062464S, 062464B OR 062464A AND SPEND FIVE MINUTES ON A LATHE.

WE HAVE SUBSEQUENTLY SPOKEN TO THE PRODUCER OF THESE PIPES AND HE IS ALREADY AWARE OF THE PROBLEM AND EACH PIPE IS CHECKED WITH TWO DIFFERENT ROSE NUTS. THESE MAY OR MAY NOT BE THE SAME AS YOURS.  THIS IS NOT A NEW PROBLEM I RECALL MACHINING ROSES WAY BACK IN 1980.