Good morning,

during assembling of my 16H engine I have more and more question on the lubrication functionalities of the Norton engine. I found a lubrication diagram of a post war Norton engine describing most of the functions but there are some left I do not understand.

On the crankcase there is a hollow brass screw with two inserts in it (metal ball and a hollow screw fitting the ball)





I guess this is the breather outlet of the crankcase. But what role does the two parts take over? If I tighten it completely I may reduce the outlet diameter to a small diameter because I guess the ball and the screw do not seal completely because there is a groove cross the bottom of the screw. If I do not tighten it the ball is loose in the brass hollow screw but maybe without a real role??

Any explanations for a greenhorn like me.

Thanks
Phillip

email (option): phillip.thaler@gmx.at

Phillip,

You're not the only one!

But first read this on Rob's site, scroll down, and you'll see it:

http://www.wdnorton.nl/Mysterious_parts.htm

I have read that on other engines of that time period, the vacuum created in the engine also helps to keep the oil inside the engine, so that it leaks less.

On the downward stroke of the piston pressure builds up, and has to go out at the breather valve.

On no account connect this breather pipe to the breather pipe of the oil tank, that restricts it too much!

Hope this helps,

Lex

email (option): welbike@welbike.net

Thanks Lex,

that definitely helps. So this means the ball shall be able to move in the breathing valve. I will consider that.

Thanks, this forum is really very helpful.

Phillip

email (option): phillip.thaler@gmx.at

Phillip,

On the downloads page of my website www.norton.nl you will find the Maintenance and Instruction manual for the 16H with the oil system as well!
You do not need to be stuck with a postwar scheme although its mostly similar.

The manual does not give an elaborate explanation of the crankcase breather.

Cheers,

Rob

email (option): wd16h@telfort.nl