Primary Chaincases, A Photgraphic Record

G'day All,
I thought I would try and start a thread where we can record photos of chaincases we know are 100% correct for a particular model/year of bike and haven't been altered to fit. This would be a very handy reference for others needing to source a chaincase for a bike. For instance, I have two different chaincases for my 1938 Norton ES2, both of which are incorrect of which one has been altered to fit. It works but I'd prefer a correct one. If you check the parts list for 1938 there is actually 4 different cases listed for different models.

The inner section:
1 for models 1,16H,18,19,20,50,55
1 for model ES2
1 for models CS1,CJ
1 for models 30,40

The outer section:
1 for models 1,16H,18,19,20
1 for model ES2
1 for models CS1,CJ,30,40
1 for models 50,55

So as you can see chaincases aint chaincases and this is for one year only. After speaking to a reputable Norton specialist who has over a dozen pre war chaincases and is not sure which models/year some are for, he gave me the idea for this thread. The differences can sometimes be hardly noticeable which is why we see people selling cases that "fits all these models", yeah right !! Four photo's would be ideal, one of each side of inner and outer, but in reality most are going to be fitted to a bike so next time you have the outer off, two photo's of each side of the outer and one of the inner inside would be great along with dimensions of holes etc if you have the time. Also mention if the inner section has any offset in it. The last one I got which I was sure was correct, has offset where the crankshaft hole is. It is actually recessed back towards the crankcase about 1/2" which then means the rest of the case is sticking 1/2" further out from the bike if that makes sense. And of course mention the model and year. Please don't post pictures of unknown cases and then ask which one it is because we are bound to get wrong answers which defeats the hole purpose of this thread. Hopefully we can get quite a library going.

Well, I would love to start but I don't have a correct case :roll: , so the floor is yours.......

I hope you realise Glenn that we're never really going to find our way out of this one...

It becomes more complicated because the numbers changed from 1938 to 1939 as well, but apart from the forks, the bikes were little different.

You're not likely to come across many International or CS/CJ OHC cases and the major difference between the other models is that the mountings differed between the cradle framed ES2 and all the others with the open diamond frame. This is fairly logical as the engine plates were different.

Pre-war, the 16H was Norton's biggest seller and if you add to that the 100,000 odd WD16H and Big 4 models, the chances are that 90% of cases which turn up will be for those models. There are not only Nortons to bear in mind, I'm pretty sure that wartime Royal Enfield chaincases were made by the same sheet metal works (probably Talboys). I've seen Norton outer cases on Enfields. The Enfield does however have very different mountings with a 'box-section' bracket and the reinforcing ribs are quite distinctive.

For 1937 / 38, the inner chaincases were numbered 3653 for the diamond frame and 3654 for the ES2 - This changed to 8985 and 8986 for 1939 and all this time and through the war, the WD models had a part numbered 3410 but I can think of no reason why it should be different unless the part number included a colour code.

I have seen inner cases with welded flanges and others with a complete pressed rim but they are certainly interchangeable.

Post war plunger cases were certainly different again and the outers have a very different edge profile.

I have a 16H inner case hanging up at the moment so I'll start the ball rolling shortly and photograph that so you at least know what you're not looking for !