Engine Indentification required

[Rob]

Hi,

I have what I always thought is an EW engine. The engine number is YE6669. It has a couple of differences to my other EW crankcases.

a) It has three locating holes around the magneto entry hole recess.

b) The magneto entry recess is also smaller in diametre to the other crankcases. Approx. 47 mm vs 62 mm diametre.

c) There is a threaded 1/2 inch hole in the crankcase just around the crankcase from where the magneto is mounted (immediately above the engine number location)

What do I have? Any advice is appreciated.

Rob

[Alan Cun]

Yes Rob,  The earlier EW Dougs have the magneto gear inside the timing case running on I think 3/16 rollers. The magneto end had had a double lug taper that fitted into the gear centre allowing the magneto to be quickly removed without losing the timing. From my experience this set up was very wobbly and possibly caused premature gear wear. OBs also used this setup.

The size of the hole in the case was then increased to accept the mag gear fitted to the magneto. A sealed alloy end plate was also fitted to the four screws in the magneto to allow an oil seal. Some of the later models used this principle but the S6 and T6 used a single spring loaded quick release drive lug.

Hope this is clear enough if not I can post some pics.

regards Alan

[Rob]

Alan,

thanks for the reply. It now make sense to me.

Any idea what the 1/2" hole would be used for?


Rob

[Ian]

Could it be for the breather ?

[Rob]

ian,

I have some photos to be posted that might help. You could be right.

Thanks

Rob

[Dave]

Photos added.

[Doug]

Rob,

The three holes are to mount the steel housing for the magneto q-coupling bearing race that Alan mentioned. Looks like this:






This one is a spare. Rusty on the face as you can see (hidden by the magneto), and the bearing race would need replacing (presses in); but you can have it for the cost of post if something better does not turn up. I will be in Brisbane early October so the post could be very cheap indeed!

As for the holes on the side of the timing case above the engine number; I do not think that is original. Probably someone's idea of an extra breather. The standard breather would be for pressure to exit with any surplus oil out the standpipe at the bottom of the timing chest. This led via a tube over to and dripped/blew on the primary chain.

-Doug

[Rob]

Doug,

thanks for the summary and generous offer which I will take up. I'll contact you via a PM.

Rob