Code No. 23009-AH001



To improve the performance of CR-Z using the factory Head gasket, the factory bore sealing proof stress restricts the improvement.
HKS GT Supercharger Kit can make the CR-Z a high performance hybrid car by installing the HKS Metal Head Gasket Kit. This kit includes the exhaust manifold gasket to be durable under using the gasket with the vehicle equipped with the supercharger which generates high EGT.
This Kit was developed to upgrade the engine internals during developing the HKS GT Supercharger 7040 Pro kit.



Head gasket

Exhaust manifold gasket





  • High engine output parts. Factory replacement type.
  • The shape of the exhaust gasket is the same as the factory gasket.
  • Improved the bore seal proof stress at high engine output and boost pressure by redesigning the structure without upgrading the Head Bolt. (Bore seal pressure of the contacted surface was improved by 20%)
  • In-house test at 300PS confirmed the durability and safety.
  • 2 types of the Head gasket kit are available; the 0.8mm type is for the factory replacement, and the 1.2mm type for the compression ratio adjustment.
  • The Exhaust Manifold Gasket uses the 3-layer seal bead design (t=0.6). (The factory is 2-layer design (t=0.4))
  • The bore size is enlarged to 75.0mm from the 74.0mm factory gasket bore size.



  • To maintain the bore seal proof stress, the stopper’s height was adjusted. Narrowing the width enables the high proof stress with the factory Head Bolt axial tension. Also, optimizing the bead plate’s angle of the oil and water cooling sealing part improved the sealing’s contact pressure without affecting the bore sealing’s contact pressure. Fully coated gasket’s surface can improve the rigid connection of the cylinder head and block when installing the gasket.
  • The 3-layer exhaust gasket improves sealing durability to be used under high exhaust pressure.




●Independent Bore Stopper & Seal Bead ⇒ Separated Type

  • The bore stopper and bead are separated as placing the stopper that the tightening force is concentrated around the bore, and placing the bead around the stopper. The bore stopper load can be increased with this design, which is not possible with the factory combined type. Also, the separated type can prevent the cylinder head and cylinder from deforming since the stopper is located inside the hard bead plate.



■Performance verification

* The pressure is equally and strongly applied to HKS Head Gasket comparing to the factory gasket.



Engine Thickness (mm) Compression Ratio Bore Code No. Manual Remarks
LEA-MF6 0.8 ε=8.7 (w/ HKS Pistons) φ75.0 23009-AH001 * To be discontinued. Exhaust manifold gasket included.