Coolhands
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- Joined
- Sep 16, 2021
- Messages
- 155
Found this under 1972 on the Norton Owners Club:
“There was also a new high lift camshaft, known as the SS. Norton distinguished later even faster ones though by calling them SSS and SSSS, Triple S and Four S, or 3S and 4S, but these were never fitted to a production road engine, except perhaps the Production Racers.”
My understanding is .016 gives best power, .010/.012 gives quietest running for road use.Looks like a private stamping with someone relating that it has or at least had a 4S cam.
My limited understanding on a 4S cam is it needs more lash/clearance. .012" ??
Someone else could confirm. You can check the exisitng lash to see where it's at.
The head may or may not be modified.
You can have a good idea by taking the rocker covers off, putting a degree disc on the crank on the primary side, removing the spark plugs and measuring the lift at the valves at various crank positions. You will also need the rocker ratio which will be 1.1:1 or thereabouts to calculate the lift of the cam. Then compare to the various cams available.Never know what cam is in that motor until you pull the motor apart.