Originally Posted by tabetha
It does both(cooler+heater) as natural tendency is for heat transfer from hot to cold, so a warmer when engine is cold then a cooler when oil temp overtakes water temp.
tabetha
Seconded!
If it is for a track car I would remove it and fit a proper air -> oil cooler and do a proper job of removing the coolant hoses. Then you have one less thing to go pop!