I had a mini disaster yesterday, the fan hit the radiator and made a mess, and I lost all the coolant. No idea how long I was running like that - I was paying attention to the fuelling and not the temperature.
I think this was another consequence of lowering the engine 20mm - the viscous fan now overlaps the rad bottom tank, making contact possible.
I had done 650 miles before it happened, so I'm still a little confused why it didn't happen sooner.
I was about 5 miles from home, and as luck would have it, a nice chap who builds classic touring cars was passing with his trailer empty, so quickly loaded it up and dropped me home.
I've tested it today with my old standard rad, and there's no harm done to the engine, which is a relief. New 4 row radiator should be delivered tomorrow.
I've cropped the leading corner of the fan blades too, so hopefully there'll be no further contact. I suppose the fan will be less efficient at cooling like this, but hopefully the extra capacity of the diesel water pump will make up for it to an extent.