Hi, Recently retired so am relatively new to old bikes. Just finished rebuild on !961 B40 which took 18 months. My question is regarding the oil feed to the rockers. It would appear they are not pressure fed due to returning oil pressure being vented into the tank. It obviously works but should I put in a pressure relief valve on the tank return to ensure a pressured feed to the valve gear.

You have answered your own question - "It obviously works"  So there is no problem,the valve gear only needs to be wet, too much oil in the head area will encourage leaks and blue smoke. Have you got a copy of the Rupert Ratio Unit Singles engine book,if not I'd suggest its a good idea. Loads of info in there.    

http://www.ratiopublishing.co.uk/

 

Thanks jonv8 only asked because valve gear seems noisy. set with DTI so should be good. Will find a copy of suggested book. Thanks

Rupert ratio volume 1 rare as rocking horse droppings. Is there anyone out there willing to sell?

Ebay. Or you can buy direct from Rupert ratio site

Thanks robido managed to get into Rupert ratio website and order

If you restrict the return in anyway I would think you might have problems with oil build up in the cases, as said valve gear just needs to be wet, if it's excessively noisy then check the usual things, sloppy rocker bushings, worn rocker pads, worn lobes on the camshaft, sloppy lifter bores,worn guides and of course clearances.

Thanks for your thoughts. All stuff you suggest hopefully covered during rebuild. Friend with old bikes says it sounds fine and I am comparing it to newer bikes.The oil feed was just a thought. Thanks again