Pressurized Swirl Header Tank

Whether you race, do track days, autocross, or just enjoy your Lotus on the street, removing heat from the engine is a critical function to reduce engine wear and maintain power. It's no secret that aeration of the coolant hinders its ability to absorb and transfer heat. The coolant becomes aerated from localized boiling around the cylinder walls (creating a layer of steam around the cylinder walls) in addition to turbulence from the water pump and coolant passages. NASCAR, Formula 1, and other race series have developed great strategies involving pressure and swirling to help combat these issues, which have long since trickled down to mere mortals. The first is with pressure. Simply put, the more pressure, the better. Pressure not only increases the boiling point of the coolant, but it also reduces the size of the air bubbles/pockets in the system. Higher boiling temperatures equate to less fluid boiling and therefore less air in the system. Reducing the air bubble size from greater