HKS - Headgasket Set - 0.7mm Thickness - FA20 / 4U-GSE - Subaru BRZ / Scion FR-S / Toyota GT86

As the cylinder block and head are not rigid body, when the Head Bolts are tightened, the gap between the surfaces and the surface pressure applied is not even across the whole surface. Moreover, due to combustion pressure and vibration while driving, the conditions are continually changing and the contact surface is being continually beaten. As a result, a good gasket must ensure that contact surface pressure is spread as evenly as possible and also adapt quickly to the ever changing gaps that can appear in the contact surface to maintain a good seal with good pressure.

STOPPER TYPE HEAD GASKET
A high pressure seal is formed around the combustion chamber through the use of stoppers which create a step within the gasket for optimum sealing. By making the stopper part of the plate also allows the fold to be smaller while maintaining structural integrity. One side of the plate is completely flat meaning that it can be layered with the stopper to allow stoppers to be used in even the tightest of locations around the combustion chamber forming a high quality seal. Compared with other gaskets of the same thickness, there are more layers in these gaskets giving flexibility which allows the gasket to maintain a good seal even when the engine tries to vibrate and move.

Opposed Bead Stopper Type
If you don't have to worry about the distortion, you can use this to improve the sealing. This type is much better than bead type in matter of sealing. Opposed bead stopper type provide more balance in surface pressure.

Independent warter hole type
Water holes and Head Bolt holes have "independent bead" that is the mainstream technology in motor racing. It reduces possibility of overheating even combustion gas leakage due to high horsepower. Because of the new design of bead shape around Head Bolt hole and water hole, crack around Head Bolt hole will be prevented.

BEAD TYPE HEAD GASKET
A bead is a type of spring used to maintain surface pressure which is very well suited to head gasket use. The beads are laid out to provide optimum pressure and seal around the combustion chamber. By carefully designing and adjusting the bead shape and heights, precise control of surface pressure is achieved for optimum results. Using a combination of 3 different types of beads allows maximum efficiency and performance.

Disclaimer: CSG is not responsible for improper install or damage to engine during install process. Seek a reputable professional tuner/mechanic to install this part. Reduces compression ratio (of stock displacement) from 12.5:1 to 12.4:1. Values are calculated. OFF-ROAD USE ONLY.