[iansoady]

I wonder whether anyone has close-up photos of the oil regulator and / or oil pressure tell-tale for my Model 10? The current regulator has a fairly home-made looking knob on it; the tell-tale, as mentioned before, has been replaced by a gauge.

I have sketched what I think a tell-tale could look like:



Made out of stainless with a brass piston / indicator. Any comments?

[iansoady]

As you will all know, the Model 10 is a dry sump system but holds its oil in a reservoir below the crankcase - a bit like Enfields etc although theirs is behind the crankcase. This means that only a feed pump is required - the oil, once it has passed through the engine, drains down through holes in the timing chest (and I assume the crankcase itself) which is quite a neat system.

However, it differs from the photo in the Motor Cycle of 1930 (annotated version below). The original position of the tell tale is now occupied by the regulator, which is a simple needle valve affair. The tell tale is, I believe, quite different from those fitted to other models (no surprise there) as it screws into the oil pump cover plate via a 26 tpi thread of around 7/16" diameter (not yet accurately measured). Where the original restrictor was placed, is a simple brass plug allowing oil into the timing cover and thence to the pump.

I think I'll have to make my own tell tale. The bike came with a pressure gauge which was quite neatly fitted but I'm not keen on it as it doesn't look right.

The only thing that concerns me slightly is that the oil needs to be pumped up from the bottom of the reservoir and that when freshly filled there will just be a column of air in there. I know that on Velocettes, which have a non-return valve in the feed line from the tank, it's absolutely essential to make sure there's no air in the feed pipe otherwise the pump cavitates and complete engine destruction follows in short order.

The other thing is that the brass plug (which also doubles as the drain plug) screws into a loose steel sleeve which looks in great danger of just dropping into the crankcase as there's nothing stopping it. It does have some form of key stopping it from turning however.

Any views on this?




For comparison this is a detail view of Roger Gillett's restored bike: