Our K series BMW 3 series E30/E36/E46 upper coolant neck for the K24A2 (RBB) style cylinder head is a new take on our original coolant neck. Since our swap positions the engine as far back in the engine bay as possible, our upper coolant neck is needed to route the upper radiator hose inlet away from the firewall and towards the radiator. 

We machine the base out of 6061 aluminum and then weld on a 1.25” inlet pipe to position everything neatly in the engine bay. The coolant neck features a ½” NPT port for the heater hose, and also a plug for those deleting heat. 

We also machine our own coolant temperature sensor bung that’s welded onto the inlet pipe so the factory E30 sensor can be used to operate the stock temperature gauge.