Just a few additional comments:
- The Lorraine W12 e2b does use castor oil ('huile de ricin') for lubrication (page 50 of the 'Centre d'Instruction des Spécialistes de l'Aviation' guide). The warm pressure required for a new engine is 2.5 Kg/cm3, and the operating temperature is between 60 and 70°C.
- Water circuit: The same manual has some interesting information. Demineralized water is used, preferably boiled water... Even if it doesn't appear to be a standard measure, it is advisable to add 25 to 40% neutral glycerine to the water to prevent it freezing when the engine is not running.
- The 'Centre d'instruction de l'Armée de l'Air' also refers to a possible water fillable container at the top of the cylinders (page 36): “No high points in the piping installation without possible release of water and steam (on the ground, when climbing, or in horizontal flight).
The radiator (or feeder) must be loaded on top of the cylinders, both in climb and horizontal flight.” The reason for this setup seems to be the possibility of water vapors escaping at the top of the water circuit. The manual also states that the radiator/feeder cap might be drilled for this purpose. In fact, it was specified to empty two liters of water to leave room for expansion and escape of water vapour at the top of the circuit (page 50).
In spite of several innovative features, the 12E engines family, designed in 1923, was somewhat outdated even for 1927. The power output with their operating pressure, temperature and RPM; was limited without overfeeding, unlike Hispano-Suiza (V12 700 HP attained in 1930). IMO, this is one possible explanation for the continued use of castor oil instead of mineral oil.
BTW Yes, Levassor (not Levasseur)
, Before his sudden death in 1897, was an famous early automobiles designer, a time associated with Panhard, then Daimler and even Peugeot.
LTM