Valve clearance?

My Rudge runs zero inlet.  I think that because the  running conditions can vary so much  its difficult to predict which parts are going to expand first   ,so a little clearance is a safeguard  in case the  valve  expands first and   leaks with loss of compression  and seat burning. Just a guess !!.

Continue to use 0.002" for inlet and 0.005" for the exhaust. Post war singles have zero clearance with the pushrods free to rotate.

Specifically on singles:

I have always been told to set the clearances at zero on ohv singles, that is, just free to rotate when cold.  It is my understanding that when going from cold to hot, the elongation of the cylinder (and head) will create the required clearances because the cylinder and head will expand more than the pushrods will, thus giving adequate clearance.

Mike  

I use the "free to turn pushrod" method on my 1961 ES2 with success. It is also way my 1960 Royal Enfield Bullet 500 is set, also with success. The factory service manuals for both bikes say to set them this way.