Questions about castor oil...

[Lufbery]

All,

I know that castor oil was used as a lubricant for rotary engines in WWI. I'm pretty sure that it's a type of vegetable oil, and I know that pilots couldn't help but ingest some of it when they flew. I also know that much has been made of the substance's ... er ... laxative properties. :P

However, I have a number of questions:

1) Where was it produced and how available was it during the war? I've read that there were general shortages in Germany toward the end of the war, but one would think that vegetable oil would be easy to refine and grow locally.

2) Was it only used in rotary-engined craft?

3)Was castor oil used in rotary-powered planes because the pilots would ingest it, or were there other reasons?

Regards,

[EdStevens]

Castor oil is a natural oil produced from the castor bean plant. Although there are many varieties of plants in the castor bean family, the castor bean used is a tropical plant, and most castor oil is produced from plants grown in India, Brazil and the U.S. Growing it in Germany, as far as I know, was not an option. Hence their need to find substitutes as the war progressed and their supply dwindled.

The oil has very useful properties, including an ability to stick to and lubricate very hot moving metal parts. This, and the fact that it remained a lubricant when mixed with gasoline, made it ideal for use in rotary engines, where the oil and fuel are combined before entering the engine.

Castor oil remains an important natural product today. It is a component of Castrol motor oils, and is used for many other industrial uses, including paints, nylon production and food flavourings. Although the castor bean contains a deadly poison, this is removed during the production of pure castor oil.

As far as I know, and I may be corrected, castor oil was not needed or used for lubrication of inline engines in the Great War.

I do not know much about the properties of castor oil, but I read that it was common for pilots to carry a bottle of blackberry brandy, thought of at the time as an antidote for the effects of the burned fumes! :-[ :-[ :-[

JASTA75

If the gas mixed with the oil,were rotorys
two stroke engines?

Hi all

EdStevens is right, castor oil is the best lubricant for a rotary, even today, it is the only one (even if some research are beeing conducted) that can resist to high temperature and not dissolve when mixed with fuel.

Baron, rotaries are four strokes.

Other engines were generally lubricated by mineral oil, but we found that castor oil was used in some Hispano up to the thirties.

Regards

[Lufbery]

If the gas mixed with the oil,were rotorys
two stroke engines?

That's a common misconception. Check out these URLs for more info:

An animation of a Gnome rotary clearly showing four strokes (look closely at the valves, you'll see it.)

http://www.keveney.com/gnome.html

Rotary engines: 2 or 4-stroke? (A thread I started here a while back):

Rotary engines: 2 or 4-stroke?

Regards,

[RLWP]

If you search the internet for Castrol R you will find that castor oil lubricants are still available today!


Richard

p.s. Gentlemen of a certain age will wax lyrically on the smell of Castrol R in motor racing in the past.

[Dan_San_Abbott]

Lufbery:
* * Castor oil was used in rotary engines as a lubricant, because it was not diluted when mixed with gasoline/ petrol/benzin. *On average the consumption of of the castor oil was approximately 10 % of the fuel consumption. *The problem was that most rotaries engines the fuel /air mixture was brought in to the crankcase and then distributed to the cylinders. *This interferred with the lubrication of the crankshaft, rods and cylinder walls. *If the oil was diluted by the fuel, then the engine suffered from lack of lubrication. This was the problem the Germans were experiencing with the synthetic oils they were using in 1918 with the rotary engines.
* * * * * * * * * * * * * * * * Blue skies,
* * * * * * * * * * * * * * * * * * *Dan-San

[Lufbery]

If the oil was diluted by the fuel, then the engine suffered from lack of lubrication. This was the problem the Germans were experiencing with the synthetic oils they were using in 1918 with the rotary engines.

Thanks, Dan-San. Here's a follow-up question: What synthetics did the Germans use to create their synthetic oil? Does "synthetic" mean that the oil was neither of plant (like castor) nor of mineral (like petroleum) origin?

Regards,