Rohan said:
The Norton Factory manxes were rebuilt after every major race. So would have been many privateers bikes ?? (In the 1970s, Factory Trident racers had their cranks changed every 3 races.)
Are you saying that you KNOW that the factory didn't replace bits as needed, to get that reliability ??
P.S. Its been said that after all .And has been hinted that - may have been . Somewhere, it is mentioned that Ken Kavanagh commented that , so this may be a hint ?
Uh, what does a Triumph Trident motor have to do with Norton Manx engines? Your "P.S." comment is going to be the acknowledgement for your new book on Norton right?
How about actually picking up a book like Mick Walker's on the Manx Norton? If you did then you could credit it with the following written about the Manx by Ken Kavanagh, A FACTORY RIDER:
"Maintenance was almost nil; check the tappet clearance, adjust the chains, blow up the tyres. A whole European season could be done with three sets of valve springs, two spare valves, some spare rings and one big-end - maybe no more than fifty quid - and it could be overhauled in anybody's backyard with a few spanners."
Manx crankcases would crack across the drive side main bearing, and between the timing side main bearing and oil pump cavity, but only if stress from some other part breaking, a dropped valve for instance, put an unusual load or force on them. Otherwise they were no more prone to cracking that any other British bike engine, mag or aluminum used in racing, and if well maintained and cared for will last for decades of racing.
The Canadian importer for Nortons, McGill, who was involved in racing Nortons from WWII onwards into the vintage scene, said the long-stroke Manx engines were as reliable and needed as little maintenance during a season as a Briggs and Stratton lawn-mower.
90+ year old Bob McKeever, who raced a Manx on the beach at Daytona and who with his son is still involved in racing them , has a rider currently running and winning races on a cammy Norton with original pre-WWII magnesium crankcases.
So if you have an old Manx and you have it correctly put together and run it sanely, there is nothing you have to worry about.
Rohan, as usual you do a disservice to the history of Norton motorcycles and the Norton community in general with your hearsay , unfounded illogical conclusions and assumptions.....