Performance head gasket PSA XU5J XU5JA XU9JA XU9J4 XU9J4Z XU10J4

Here we offer several performance head gaskets for XU5, XU9 and XU10J4 engines from ATHENA and COMETIC, whose technical specification you will find below.

Technical specification of the OEM gasket

• Engine bore: 83.00mm (XU9J4/Z) / 86.00mm (XU10J4)
• Compressed thickness: 1.30mm (XU9J4/Z) / 1.15mm (XU10J4)

Technical specification

• Engine bore: up to 84mm (for XU9J4 and XU9J4Z)
• Compressed thickness options: 1.30mm, 1.60mm
• Gasket type: MLS
• Part numbers: 338400R, 338399R

Designed and manufactured in Italy, Athena performance head gaskets are available in two forms:

• MLS: these gaskets are made up of several layers of stainless steel stacked and riveted together. The stainless steel layers are laser cut for greater accuracy and are given an elastomer-based surface coating (NBR or FKM). To achieve an optimal seal, the contours of the cylinders and of the water and oil passages are embossed. For the most extreme applications, additional reinforcement is fitted around the cylinders.
• O-ring: these gaskets consist of a steel core faced with asbestos-free aramid fibre and an AISI 304 stainless steel ring (around the cylinders). A bead of silicone applied at the critical points (water and oil passages) guarantees maximum sealing of the head gasket. This type of gasket is essential on heavily boosted engines.

Technical specification

• Engine bore: up to 84mm or up to 85mm or up to 86.5mm or up to 88mm
• Gasket type: MLS
• Number of layers: 3, rising to 5 for gaskets from 1.42mm compressed thickness
• Compressed thickness options: 0.69, 0.76, 0.91, 1.02, 1.14, 1.30, 1.37, 1.42, 1.52, 1.68, 1.78, 1.91, 2.03, 2.13, 2.18, 2.34, 2.49, 3.05, 3.56mm
• Part numbers: C4225, C4225-027, C4225-030, C4225-036, C4225-040, C4225-045, C4225-051, C4225-054, C4225-056, C4225-060, C4225-066, C4225-070, C4225-075, C4225-080, C4225-084, C4225-086, C4225-092, C4225-098, C4225-120, C4225-140, C4226, C4226-027, C4226-030, C4226-036, C4226-040, C4226-045, C4226-051, C4226-056, C4226-060, C4226-066, C4226-070, C4226-075, C4226-080, C4226-084, C4226-086, C4226-092, C4226-098, C4226-120, C4226-140, C4227, C4227-027, C4227-030, C4227-036, C4227-040, C4227-045, C4227-051, C4227-056, C4227-060, C4227-066, C4227-070, C4227-075, C4227-080, C4227-084, C4227-086, C4227-092, C4227-098, C4227-120, C4227-140, C4228, C4228-027, C4228-030, C4228-036, C4228-040, C4228-045, C4228-051, C4228-056, C4228-060, C4228-066, C4228-070, C4228-075, C4228-080, C4228-084, C4228-086, C4228-092, C4228-098, C4228-120, C4228-140

Founded by Bob Gorman in 1989, Cometic is recognised worldwide as a leader in the design and manufacture of performance head gaskets. Like the rest of the brand's range, they are made in the United States. Cometic performance head gaskets are built from several embossed stainless steel layers held together by rivets. There are three types of Cometic head gasket:

MLS: the equivalent of the Athena MLS gaskets, these multi-layer gaskets (between 3 and 5 stainless steel layers depending on gasket thickness) are embossed around the cylinders and the fluid passages.

• MLX: this gasket shares the same base as the MLS gasket, but adds reinforcement (a folded layer) around the cylinders and a special high-temperature coating.

• HP: an MLX gasket to which an additional layer has been added in order to improve the sealing of the cylinders (see below).