Cometic Lifter Block Gasket

The lifter block, also called the tappet block, houses the hydraulic lifters that ride on the camshaft and drive the pushrods. A leak here means oil seeping out near the heart of the valvetrain, or air and contaminants finding their way in. That is why Cometic lifter block gaskets matter to anyone rebuilding or refreshing a V-twin engine: a small, inexpensive part sits between the lifter block and the crankcase and is expected to hold up to heat cycles and constant vibration.

Cometic's Approach to Lifter Block Sealing

Cometic Gasket has been in the engine sealing business since 1989, and its roots are in powersports. That background shows in its lifter block gasket offerings, which are aimed largely at Harley-Davidson applications, from Shovelhead-era engines to modern Milwaukee-Eight platforms. Cometic describes its tappet block gaskets as made to meet and exceed OEM quality and made in the USA. The company states that all of its products are made in the United States with materials manufactured on American soil.

Material Choices: AFM and Fiber

Cometic does not use a single material for every job. Its tappet block gasket range has included both Aluminum Foamette Material (AFM) and aramid-style fiber options, in front and rear configurations and in different thicknesses, such as .032" AFM and .020" fiber versions.

• AFM (Aluminum Foamette Material): AFM gaskets have an aluminum core with a chemically blown, compounded nitrile synthetic rubber coating bonded to the outside layer, and they do not require gasket sealer.
• Fiber: A traditional composite approach that suits builders who prefer a conventional gasket feel. Some owners choose to use a light sealant on clean, dry surfaces, but follow the instructions for your specific part and engine.

Cometic's broader material expertise is a real advantage here. The company says it manufactures gaskets from a comprehensive range of materials, from advanced MLS (Multi-Layer Steel) to synthetic blends such as aramid fiber. That experience informs how it matches a material to a low-pressure, oil-sealing application like the lifter block.

Kits and Rebuild Convenience

Lifter block gaskets are often supplied as part of larger sets. For example, Cometic's Milwaukee-Eight cam change and complete gasket kits include lifter block gaskets along with a cam cover gasket, exhaust gaskets, pushrod tube o-rings and oil pump and cam plate o-rings. Buying a coordinated set helps ensure that every sealing surface around the cam chest is addressed in one teardown.

Shopping Considerations

• Match the engine: Lifter block gaskets are specific to engine family and model year, so confirm your application before ordering.
• Front vs. rear: Some engines use separate front and rear tappet block gaskets, often with different thicknesses.
• Surface prep: Clean, flat mating surfaces are essential regardless of the gasket material.
• Replace as a set: If you are already in the cam chest, replace all related gaskets and o-rings at the same time.

To see everything the manufacturer offers beyond this part, visit the full Cometic brand page. If you want to compare other makers' options, browse the complete Lifter Block Gasket category.