Chevrolet Performance SB2.2 NASCAR Aluminum Cylinder Heads

*HIP stands for Hot Isostatic Pressure. This process puts cylinder heads in a sealed vessel where a vacuum removes room air and any contaminants. The vessel is filled with high-pressure nitrogen (up to 30,000 psi) and then heated to and sustained at the required temperature for a preset length of time. Cooling is also controlled to ensure maximum strength and proper heat treatment. The extreme pressure and heat removes almost 100% of the internal porosities generated during casting. The material integrity, strength, and fatigue life improve significantly.