This listing is for a matched pair of Inlet and Exhaust cam to fit the 500cc (M30) International SOHC engine - with the same profile as original 500cc M30/Longstroke Manx Profile this being the profile referred to as 115.87 (inlet) and 115.88 (exhaust) profile. These cams are manufactured for us by a long established UK manufacturer to the original Norton (verniered) design. Each set comes with a useful fitting sheet.
Price is per Pair.
Back in Stock Feb 2025 - We have just had a new batch of these cams in stock, from our original cam maker whom we have used for the laast 20 years.
Background Information:
These cams are to the original Norton SOHC 30M 115.87 and 115.88 (i.e Racing International or Longstroke Manx) profile. Although being originally fitted to racing 500cc SOHC engines, a number of customers also like to fit them to their roadgoing engines - and I have used this profile for both methanol race engine and on the road - being just a bit more extreme in their lift profile than the original road-going 500 International profile cams we also sell (those being item 0052).
These are suitable for both road and racing 500cc Internationals (i.e. Model 30M, SOHC Manx and Model 30) machines.
These cams are manufactured for us by a highly experienced UK company, who have been making these cams for us for over 20 years. They are to the original Norton pattern - which includes the original vernier holes, so that the inlet cam can be 'pegged' to the exhaust cam (which is statically located to the camshaft with a woodruff key) with a special roller, in various pre-defined positions in relation to each other, therefore allowing a slight variation of valve timing between inlet and exhaust cams. We supply an information sheet with each set of cams that helps explain this. Note: the special roller that locates the two cams to each other is sold seperately - Item 0054 and we recommend having a couple spare - as very easy to drop and lose one on the floor when fitting . . . I have done that a few times!.
As a final note on this engine and cam timing design - along with the vernier holes on the upper camshaft bevel gear - which allow slight variation of timing of both cams in combination - results in a very flexible and highly adjustable means of setting the valve timing - remembering of course, that back in the 1930s - this engine was designed primarily for competition. However, the relative complexity of that design (compared to other machines of the period), alongside the also necessary shimming process necessary for the vertical bevel gear design - means that assembling an engine for the first time can seem quite daunting - and sometimes take many attempts to get right!
My only advice to help with this would be to say - be patient and methodic, and dont be disheartened if it takes multiple attempts to get the shimming and valve timing correct - most of us are the same, and although you get more familiar with the task - it is never totally easy, but worth it in the end!
