Oil overflow pipe EW350 - Missing

[geomellish]

I am currently recommissioning my early 1926 EW350.  It appears to be missing the oil overflow pipe from the bottom of the timing chest which should then drip onto the primary chain.

Does anyone have a photo or drawing of the original fitting that I can copy?

On my engine, a 7/16 UNF 20tpi straight pipe connector has been screwed into the timing case with a (loose) vertical c 1" pipe inserted into it to allow an oil reserve at the bottom of the engine (and without the chain lubricator)- but this can not be original as I imagine it would have been a BSF or BSP fitting.

Thanks, George

[Doug]

See these two posts.

Picture of standpipe in-situ:
https://www.douglasmotorcycles.net/index.php?topic=6049.msg22277#msg22277
Picture of fitting, with length:
https://www.douglasmotorcycles.net/index.php?topic=2811.msg10555#msg10555

-Doug

[geomellish]

Thanks Doug, very helpful. That fitting looks like mine but with a slightly coarser (BSF 18tpi ?) thread rather than the UNF(20tpi) that I seem to have.

I'd also like to see what the primary chain lubrication pipe looks like.  Presumably it just bends an immediate 90 degrees then around to over the chain held in place by a  compression nut onto the 'standpipe' fitting?

Regards, George

[eddie]

George,
            Don't assume the fitting in your engine is 7/16 UNF - Douglas did use 7/16" x 20 and 1/2" x 20 threads prewar. These were not UNF but of Whitworth form.
    Regards,
                  Eddie.
 

[Doug]

George,

The fitting shown in the EW crankcase is 7/16-20 on both ends; I just checked it. The other, with the fitting against a scale looks to work out to 0.050 pitch, which would also be 20tpi.

Most of the Douglas threads that I have come across were 60 degree thread angle. They liked the CEI 20 (verses 26) thread series when not using their own proprietary threads. The only Withworth threads that I have run into pre-war were coarse threads tapped into crankcase aluminum, that had to carry a load. Like the cylinder bolts and magneto studs on the OHV engines. Not a problem on the 350cc EW with its peculiar little eye bolts looped around the crankcase joint bolts.

I have found the 7/16-20 to be used on a number of Douglas oil fittings, so probably a thread borrowed from the industry. The American 7/16-20 I have found to be a good match.

-Doug

[geomellish]

Doug and Eddie, you have introduced me to a whole new world of thread sizes - my previous experience has been with vintage cars, I was not aware of these 'Cycle' sizes.But now I am, so thanks again.  At least the Douglas  7/16 CEI 20tpi (pitch 60) should match 7/16 UNF - also 20tpi and 60 pitch....

Once again, I would still like to see an original overflow pipe to the primary chain to copy for my bike. I have a couple of engine photos that show it curving out and back under the off side of the engine so I can no doubt make something from that.

Regards, George

[Doug]

George,

I have been looking for a photo of the oil overflow pipe to the primary chain, but it seems to be one detail that I overlooked when photographing other examples. Strange omission, as I will need to make one for my 350EW. It does run across the rear face of the crankcase, over the frame tube, and breathes on the lower run of the primary chain. There would have to be something supporting the far end, perhaps a clip under the cylinder base nut, as it is too great a length or tube without two means of support.

-Doug