Reinforced head gasket BMW 325i 330i E46 525i 530i E39 E60 Z3 Z4 M54B30

We offer here several reinforced head gaskets for M54B25/B30 engines from ATHENA and COMETIC, whose technical specifications you will find below.

Technical specification of the original gasket

• Bore: 84mm
• Thickness: 0.70mm

Technical specification

• Bore: up to 84.5 or 86 or 87.6mm
• Thickness(es) available: 1.50, 2.00mm
• Gasket type: O-ring
• References: 330022R, 330023R, 330141R

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

• MLS: these gaskets are made up of several sheets of stainless steel, layered and riveted together. The stainless steel sheets are laser-cut for increased precision and receive an elastomer-based surface treatment (NBR or FKM). To achieve optimal sealing, the contours of the cylinders and the water and oil passages are stamped/embossed. For the most extreme applications, reinforcement is added at cylinder level.
• O-ring: these gaskets consist of a steel sheet covered with asbestos-free aramid fibre and a stainless steel AISI 304 ring (at cylinder level). A bead of silicone applied at critical points (water and oil passages) ensures maximum sealing of the head gasket. This type of gasket is mandatory for heavily forced-induction engines.

Technical specification

• Bore: up to 85mm
• Gasket type: MLS
• Number of layers: 3, then 5 for gaskets from 1.52mm thickness
• Thickness(es) available: 0.69, 0.76, 0.91, 1.02, 1.14, 1.30, 1.52, 1.68, 1.78, 1.91, 2.03, 2.13, 2.18, 2.26, 2.34, 2.49, 3.05, 3.56mm
• References: C4352, C4352-027, C4352-030, C4352-036, C4352-040, C4352-045, C4352-051, C4352-060, C4352-066, C4352-070, C4352-075, C4352-080, C4352-084, C4352-086, C4352-089, C4352-092, C4352-098, C4352-120, C4352-140

Founded by Bob Gorman in 1989, Cometic is recognised worldwide as a leader in the design and manufacture of reinforced head gaskets. As with all of the brand's products, these are made in the United States. Cometic reinforced head gaskets consist of several stamped stainless steel sheets held together by rivets. There are three types of Cometic head gaskets:

MLS: equivalent to Athena MLS gaskets, these multi-layer gaskets (between 3 and 5 stainless steel sheets depending on gasket thickness) have embossing around the cylinders and fluid passages.

• MLX: this gasket has an identical base to the MLS gasket but with reinforcement (folded sheet) added at cylinder level plus a special high-temperature coating.

• HP: this is an MLX gasket to which an extra layer has been added, the aim of which is to reinforce the sealing of the cylinders (see below)