Athena Cut Ring Head Gasket, BMW M20

This M20 Head Gasket is specifically engineered to replace BMW part numbers 11121722734, 11121722735, 11121722737, and 11121722738 for the M20B20, M20B23, M20B25, and M20B27 engines used in a variety of BMW models, including the E12, E21, E28, E30, and E34.

Factory OEM & MLS head gaskets are only engineered to handle a limited amount of cylinder pressures before they start to leak, causing a range of issues, including engine overheating, loss of power, misfires, and in severe cases, catastrophic engine failure.

Athena-SCE Cut Ring Head Gaskets are uniquely designed to handle increased cylinder pressure caused by power modifications, making them the recommended choice for applications making 16+ psi.

Design:

Athena-SCE's gasket body is composed of Motorgasket, a reinforced material developed by Athena's R&D department. This consists of a steel core covered with two layers of asbestos-free aramid fibre and offers excellent thermal and mechanical resistance without compromising its ability to adapt to mating surfaces.

To ensure maximum sealing under all conditions, a silicone bead is also applied to critical sealing areas, such as oil and coolant passages. 

The AISI 304 stainless steel cooper rings bite into the aluminum head, providing maximum sealing around the cylinder bore and optimizing engine performance, even on engines with nitrous and/or turbo applications that exceed 2 bar boost.

Please be aware that the gasket should be 0.5mm to 1mm larger than the piston. For example, if the piston measures 84.5mm, then the gasket should be the next size up, either 85mm or 85.5mm.

Before installation, it is crucial to have the mating surfaces of the cylinder head and block professionally cleaned and resurfaced to ensure they are completely flat.

Installation instructions:

1. Make sure that the engine block and cylinder head surfaces are clean, flat, and free from any debris, oil, or coolant.

2. Install the Cut Ring gasket on the engine block and ensure that it is properly aligned. Avoid twisting or bending the gasket during installation.

3. Place the cylinder head on top of the gasket and install the head bolts or studs in their correct positions.

4. Follow the manufacturer's recommended torque specifications and tighten the bolts or studs in the proper sequence to ensure even clamping force across the gasket.

5. After the initial tightening, re-torque the head bolts or studs after the engine has been started and then allowed to cool to room temperature. This will ensure that the gasket is properly seated and compressed.

6. It is recommended to not use any additional sealant on the MLS gasket, as it is already coated with a Viton rubber sealant. Using additional sealant can hinder the performance of the gasket.

BMW M20B20 Applications:

BMW 3 Series

1977 - 1982       BMW E21       320i
1982 - 1990       BMW E30       320i

BMW 5 Series

1981 - 1987       BMW E28       520i
1988 - 1992       BMW E34       520i

BMW M20B23 Applications:

BMW 3 Series

1977 - 1982       BMW E21       323i
1982 - 1984       BMW E30       323i

BMW M20B25 Applications:

BMW 3 Series

1985 - 1991       BMW E30       325e / 325i / 325is

BMW 5 Series

1988 - 1992       BMW E34       525i

BMW M20B27 Applications:

BMW 3 Series

1982 - 1987       BMW E30       325e

BMW 5 Series

1982 - 1988       BMW E28       525e / 528e