there is several reliable routes you can take to getting the fans on for longer or at a lower temp but you need to address why its getting hot in the first place

if it warming up that quick then a blocked thermostat is most likely (£10 and half hour to swap) , try to get a "summer stat"

if thats not the cause then it could be a knackered water pump / running too lean / headgasket / the list goes on

run it till its up to temp then feel the radiator , it should be warm all over , if not then again - thermostat or water pump


as for the fans , i swear by the adjustable thermostats from kenlowe , its a probe that slides into the fins on the rad and is adjusted to cut the fans in wherever via a dial , easy enough to wire up too