Bear: the foaming happens when oil gets mixed with water either water liquid OR water vapour. Only time it ever foams. I have found my reading spectacles I can now type
I have yet to encounter any machine that uses oil vapour to achieve lubrication or cooling. I am aware there is a whole new section of science called nanotechnology but I cannot see the oil vapour being used in the technology we are using (publically in civil use) today.
If oil does vapourise it is past it's usefulness and it gives of a flamable gas and leaves a hard carbon residue caled "coking". Bear I know you follow the A-380 thread and it is this gas that upset the computer control of the engine causing the spline wear.
In this thread I am seeking to know what the guys are seeing on their temp guages in day to day operation. No more than that. It may well be that all RR turbines run with the oil around 180C. This adds up when you realise they have THREE turbine sections as opposed to the TWO in GE products.
All repilies very welcome. Barit1 if you can remember what your whirlygig oil temps ran at then please advise.