I need to reduce the lubricant temperature in a motorcycle engine.? I've been allotted this project in a motorcycle company in India in which I need to reduce the average temperature to which a lubricating oil gets heated up, in an engine for one of their models. Now I did see the flow path of the lubricating oil - sump to a filter, filter to a gerotor pump, to the gallery - splitting up to the crankshaft (through a centrifugal filter) and to the cylinder head, after which it lubricates the piston, valvetrain, timing chain and drops into the sump back again. Now I don't have a clue of how to REDUCE the temperature to which it heats up. Here are some facts: a) They recommend 10W30 for use as lube in that engine. So do I try measuring the temperatures with 20W50 or something? I've heard that higher the viscosity index after that W, higher is the high temperature performance, although I'm not so sure of how changing the oil would reduce the average temperature it gets heated up to. b) Does introducing an oil restrictor have any effect? c) Is it of any use trying to change the quantity of lubricating oil? 900 ml is the lube oil capacity of that engine, so what will happen if I pour 1000 ml of lubricating oil and perform that test? d) Changing the oil pump. That does have an effect, but that's the only thing that I've tried so far and I need more ideas. e) Changing the oil filter. Will that have any effect on the TEMPERATURE? If so, HOW? I need to finish this project within a month and I absolutely haven't a clue of what and how to do this. PLEASE HELP!