Workshop question: An L. Dubrulle oiler

Normally on a Wednesday, Jos van Genugten will give you some technical advice and shows what he has done in his workshop. He is working on a 1899 Amedee Bollee and this time, he is asking you for advice;

In the workshop, there are often parts or systems that are incomplete, non-functional or not properly mounted. In those cases, we have to find out how something is supposed to work, why it doesn’t work now and how it should be mounted in order to work.

In today’s case I have a L. Dubrulle oiler. This is a system built from just before 1900 to just after, approximately. It’s a pressurized oil tank with 2 overhead dripping glasses, 2 outlets and a hand pump. The only question is, what are the functions?

It’s clear that the 2 outlets are for 2 cylinders, since the oiler belongs to a 2 cylinder Amedee Bollee engine. What is not clear is how it should operate. Where does it get pressure and where does the hand pump lead to?

The engine has a cover on the crankcase with 1 plug that could be used to hook up to the oiler. I think this could be the pressure source, since the engine has 2 pistons running simultaneously, when they make a downstroke, quite a lot of pressure is generated. This makes sense also, because the oiler has a one-way valve in the pressure inlet, so that if the pistons would go up again, they do not suck the pressure back out of the tank.

But then, there is the hand-pump. This could in my opinion also be connected to this 1 plug in the crankcase. The handpump sucks oil out of the oiler and pushes it in a copper line. This could be to pre-fill the crankcase with a little oil before starting. Since the crankcase is the only oiled component (gearbox is greased and it’s chain driven so no oiled rear axle), I cannot imagine where the oil should go other than in the crankcase.

Since there is no dipstick or any other way to check for oil level, and there is a drain valve on the bottom, common practice could be after driving to drain the oil and “give it 2/3/4 pumps”.

Who can enlighten me on this subject? Where should it get pressure and what does the pump do? I’ve attached a few pictures and also a schematic overview of the pump.