Oil Cooler Kit For Nissan 240sx S13 with RB20 RB25 RB26. Chase Bays. Oil Cooling is one of the most overlooked aspects we see on S-Chassis builds with RB engine platforms. This not only causes decreased performance and reduces the oils ability to lubricate but being that it's a shared vessel with the coolant, it also reduces the radiators capability to cool the water/coolant.
