These braided oil cooler hoses are the best available and although longer for the mini clubman many mini racers use these for the extra length to enable fitting to a standard mini. Short hose: 14", Long hose: 24".
The correct running temperature of the oil is perhaps even more important than the water/coolant temperatures - so let us consider how to control them. Mainly because it seems to be the most misunderstood of the whole process, and oil cooler fitment almost a reflex when over-heating occurs where a tuned engine of any type is concerned. And in many cases on standard production road cars for that matter.