The tube that goes from the crankcase breather and supposedly spits oil on the chain, is it a rubber tube or a metal tube. If it's rubber, how does it clip over top of the sprocket. The nipple of the fitting on the breather is made to accept a rubber hose, I'm just questioning wether it's correct or should it have been a fitting to accept a flared metal tube. Also on the subject, the surplus oil tubes from the timing chain and the valve, were they copper or steel, how long and what shape were they. I seem to have a lot of trouble finding photo's of them.
Thanks
This pic shows the magneto drive drain, (its far too tidy to be my bike)
On the crankcase breather, mine is a copper tube.
I would have thought all 3 were copper originally.
All tubes on and leading to the engine were originally copper.
Only the oil lines (upper part connecting to the oil tank)were partly replaced by rubber on the later models.
The engine breather tube was also copper and was indeed flared to fit onto the breather valve union nut.
Do you have a breather valve? I did come across engines on which there was no valve, just a connector.
The copper tube is bent in such way that it goes up about vertically from the connector, then bent backwards at about 90°,horizontally crossing over the inner chaincase fixing stud and drops down and backwards at about 45° to just short of the chain.
I am one of the silly sods still not able to publish a picture here but I hope the description is clear.
(At least for Norton owners)
Sam, the pipes were all copper and on the earlier bikes at least, were chromed (dull chromed in the case of WD machines but perhaps later cadmium plated).
Although some carb parts were later unfinished brass, it was not generally the practice to leave unfinished copper, despite the risk of embrittlement.
I'm not aware that the short pipe was routed actually onto the chain and in fact, on an engine in good condition and with the valve fitted in the union, not a lot emerges there.
You should be able to enlarge this photo up to see the pipe fitted to mine. It has a short larger diameter sleeve on the end which is gently flared.
This is an original dull chromed part but some of my other lines are simply tinned which is a technique that Lex suggested and it looks pretty good alongside the original.
The hose spigot on yours is not an original fitting.
Perfect, thanks guys, thats what I needed to know. The nut I think is original, but someone put a brass nipple for a rubber hose on there. The type thats on the rubber petrol hose ends.
And I think you're right Rik, I've never seen a drop of oil come out of that thing!
Just 2 more things, earlier on, someone mentioned a flared pipe, but this is not so, there a brass fitting, the pipe is soldered into, and the brass fittling is held on by a special nut, same as the petrol pipes.
The only flared bit is on the end, where there's a bigger tube soldered over the pipe, and the end of that is slightly flared. (as Rik mentioned)
Originally the breather valve (on any make) is there for 2 reasons to stop dirt entering the engine, and to provide a vacuum inside the engine, so it leaks less.
Have seen some 16H's where people have connected the breather pipe of the engine to that of the oil tank, with a lenght of rubber hose, don't do this, it doesn't work! oil might get sucked into the engine that way!
Interesting photo Rik. My breather tube comes up at 45 degrees and then runs horizontally until a bit short of the sprocket.
Of course nothing much else has proved original on mine so no reason to beleive the breather tube is.
Interesting photo Rik. My breather tube comes up at 45 degrees and then runs horizontally until a bit short of the sprocket.
Of course nothing much else has proved original on mine so no reason to beleive the breather tube is.
Mine is as Iain describes (and I strongly believe that the pipe IS an original one - still has the original dull chrome plating), which seems a lot more logical than what Rik's photo shows. Besides any excess oil is for oiling the rear chain!
Yes Alex, I guess I used the wrong choice of words, shouldn't have said flared, I do have a bunch of those solder on nipples, like the ones on the oil lines.
Having done some searching, and checking my own website I come to the conclusion that at least for the earlier engines the engine breather pipe as shown on Kostas bike and Rik's bike are correct parts and as Lex noted the actual bend should be inbetween those. (half exited?).
Anyone having a copy of the Illustrated spare parts list will find the part 9531 shown above the inner primary chain case on page 15 at the top.
My description given earlier was based on a number of pipes that I have. None of the 5 engines (all relative later engines) I have has a pipe as shown. I tend to believe that they may have been economised somewhere in production cycle and/or frequently replaced in service. None of the pipes I have have a soldered on taper, all have a formed taper made on the copper pipe itself. I very much doubt this is an amateur forming process and thus believe that its a later version.
Yet another mysterious item.