Bikerdoc,

I leant the hard way about heat and alumnium engines with a Rover V8 powered Truimph Stag I made for my ex wife in Spain. I bought the reconditioned engine in the UK and they had painted to improve its appearance. To cut a long story short the car overheated like a kettle even in the winter, I did a few fixes like custom made high efficiently radiator, ducting to imprive airflow to the radiator, extra water capacity with 2 litre expansion bottle but with no real improvement.

One day I visited one of the local motorbike teams and struck up a conversation with one of the Honda engineers, we got around to cooling and he gave me the idea about painted aluminium engines. Next weekend, I whipped the motor out, stripped all the paint off the allumium block and heads ( very time consuming ). Problem solved, the engine stayed at 90ºc even in 40ºC summer days.

Honda fitted the XR400 with a oil cooler for a reason and I would suggest that any X5 owne,r who intends to use the bike and "give it some", has one too. Even better with a thermostat so that the oil can warm up ( Cold oils don't lubricate well ) then the termostat opens to keep the oils cool. Ideal temperature for an oils is somewhere between 80 and 120 ºC depends on the oils.

It would seem that Shineray are saving some money not painting the engines and not fitting an oil cooler but without giving too much thought of the end product which is fairly normal for China.

Symon