My ES2 1961 - recently rebuilt - worried me from the start as the wet sumping is extreme, about 1/4 litre per day. I wondered if the oil delivery from the pump is not sealing to the cover so oil is just running through the pump and into the timing case.
Taking the cover off, I found that:
- there is a hard fibre washer (part 84 on the AN exploded view) on the pump outlet spigot which butts up against an aperture in the timing cover. Inside the aperture is a spring loaded ball. So the pump has to push this ball in to deliver any oil into the timing cover/engine. This ball and spring are not shown on the AN view. Doesn't seem right, should they be there?
- just above this aperture should be the spring loaded jet/plunger which enters the end of the crankshaft. This plunger and spring are missing (I refer to parts 97 and 99 on the AN exploded view. Part 98 is there). It looks like the crankshaft has not been getting any oil.
- finally, up at the top, is a flat nut (part 102). I haven't taken this nut out to see if the ball and spring are there (Parts 100,101). I'll do this tomorrow.
Can anyone tell me if what I have tried to describe sounds as it should be - except for 97 and 98 of course, or is there something else wrong with the setup?
I'll attach photos tomorrow.
The photo shows the aperture into which the oil pump delivers in the cover (Right hand side). The ball inside can be clearly seen. My first point above applies to this.
I think the second and third points are now clear for me.
Can anyone tell me if the ball and spring should be there? Maybe to stop the oil draining back out of the crankshaft when the engine is switched off?
I think that later engines (like yours) had a spring loaded ball to prevent, or at least slow down, wet sumping when stopped. I'm not sure when it was introduced. Definitely not there in '56 models so my best guess would be from '57 on, possibly from when the head casting included push rod tunnels.
Spring loaded crankshaft jet definitely required. Without that, as you say, there will be no oil supply to the big end bearing.
Behind the top nut should be the spring loaded ball for the pressure release valve. Probably not a bad idea to replace the ball and spring. Make sure the ball is well seated (light tap with a hammer against a soft drift).
Hope this helps, Ian McD
Thank you Ian, I think your reasoning about the spring loaded ball to reduce wet sumping is probably correct. The fact that it was only included from about '57 explains why it isn't in the AN drawing.
I'll certainly be replacing all these.
I too wondered about the date of the AN diagram but the engine shown there is post '57 (with alternator and cast-in pushrod tunnels) so that's not the full explanation. I have looked at Roy Bacon's "Norton Singles" in the section where he summarises year on year changes but I see no mention of the introduction of the wet sump valve. There is bound to be someone on this forum who knows more about this.
.....that now resides with a friend and yes it has an anti-sump ball and spring that doesn't show in the parts list but is listed in the text. This bike never sumped up.
But as my engine has the spring loaded ball valve in the timing cover, why is there such an excess of oil leaking into the engine? The ball is free in its housing - can be pushed in easily and returns easily. Oil has to go through the pump and if the ball/spring is working properly and the pump outlet spigot is sealing against the casing, there should be nothing leaking into the case. Even if the fibre sealing washer is not hard up against the case, oil will still have to work its way back through the spigot/aperture clearance gap to find its way into the case. I assume the fibre washer is slightly compressible. Maybe my engine has the wrong fibre washer.
I think I will test to see if the spigot seal (fibre washer) is butting up sufficiently against the case, by putting thick washers behind it holding the timing cover away from the crankcase, and then some measurements might tell me the answer.
Attached is a photo of the timing cover with jet and spring removed from its housing and also in position.
Make sure you have this set up otherwise the oil from the pump will go straight to the sump.
This is what my engine should have but as I said, the jet and the spring are not there. I am ordering new items.
Thank heavens that the bike only did about 15 km at low revs without them, and still sounds ok.