Bike cooling system.......

I am working on a project to improve the cooling system of engines in bikes. For short distance commuters, it is difficult to get optimum performance as most of the heat produced during combustion process is used up in heating the engine chamber and it takes about 4 to 5 km of running to get the optimal performance. For getting optimality, travelling for shorter distance some air flow blockage is required in the beginning and should reopen after the engine is giving its best performance. Some sort of baffles is required which will reopen after engine reaching its proper temp. the main problem is in metros where we have to switch on and switch off engine at every signal. could you guys please help me giving me any idea.