ORIGINAL: merugo
Viscosity of olive oil has been proved to increase with pressure, so it fits engine needs. Various types of olive (apart from the crop) differ mainly for the presence of free fatty acids. The more the free fatties, the less the quality and the more disturbing the extraction method. This is important for alimentary purposes, but probably does not mean anything for model engines, since they spit quickly the oil, without possibility of chemical modification. So the cheapest olive performs as the costlier ones. What is important is to "feel" the viscosity. This depends on the crops and on the brands.
Now I have the viscometer useful for high temperature-low viscosity measurements, wait for more data after calibration. But who introduced olive oil here?
Ugo
High viscosity are not allways to be sure the oilfilm are stronger against bearing pressure. Two difference oil with same viscosity can not have same properties when we are talking about high bearing pressure.
The best to test the oil are strong are the four ball pressure test.
The other method to test pressure agains oilfilm are the electric motor with steel wheel against the other non rotating steelwheel who are connected to torque wrench. Both steel wheel are in oil. The amper meter are connected to electric motor. While the electric motor are rotating, increase pressure the non rotating wheel against rotating wheel and check amper meter. Little press (read at torque wrench) + hi amper means the oilfilm are weak and vice versa.
We had problems with Mercedes-Benz Vito van cars in first period, the engine was damaged too often. The maintenance was followed and service was completed each time these MB Vito was in car shop.
Cause 10W/40 motoroil for car was not good enough for the engine, then we replaced to use 10w/40 motoroil for lorry/truck. Problem was solvent. The engine last well.
Jens Eirik