Head Cooling Mod

Design Flaw – Ford 4.6 Coolant Flow and IMRCs

  There is a lot of discussion and disagreement out there regarding Ford 4.6L engines and their coolant flow. Several companies out there offer a “head cooling mod” (HCM) which takes coolant flow from the driver’s side cylinder head and, rather than dead-ending it like stock, ties it into the heater supply tube with the […]