Sierra – Exhaust Elbow Gasket – 18-0305-1

The Sierra Marine 18-0305-1 Exhaust Elbow Gasket is an aftermarket marine exhaust gasket used to seal the joint between the exhaust manifold and exhaust elbow or riser on compatible Crusader marine engine applications. This gasket helps contain hot exhaust gas and raw cooling water at the manifold-to-elbow connection, reducing the risk of exterior leaks, exhaust staining, saltwater seepage, and cooling-water misrouting during engine operation.

Key Features

• Sierra Marine part number: 18-0305-1
• Product type: Exhaust elbow / riser gasket
• Application location: Between exhaust manifold and exhaust elbow or riser
• Port style: Round-port gasket configuration
• Primary function: Seals exhaust and cooling-water passages at the manifold-to-elbow joint
• OEM cross-reference: Crusader 96108
• Sold as: Individual gasket
• Application type: Crusader inboard marine gasoline engines where the parts diagram calls for this gasket
• Related Sierra manifold references: 18-1925, 18-1926, 18-1929, and 18-1933, where specified by the exhaust system layout

Engine Compatibility

This gasket is intended for compatible Crusader marine engine exhaust systems using the matching round-port manifold and elbow pattern. Common application references include select Crusader GM-based inboard engines such as:

• GM small-block V8 Crusader applications, including 305350 CID / 220 and 270 model references where specified
• GM big-block V8 Crusader applications, including 454 CID / CH350 and 454XL references where specified
• Crusader exhaust systems using OEM gasket reference 96108
• Compatible Sierra manifold/elbow combinations where the parts breakdown calls for 18-0305-1

Fitment must be confirmed by engine model, serial number, manifold casting, elbow style, cooling configuration, and parts diagram.

Fitment Notice

Exhaust elbow gaskets are not universal. Confirm whether the engine uses a raw-water-cooled or fresh-water-cooled exhaust layout, and match the gasket to the exact manifold and elbow passage design. Similar-looking Crusader exhaust gaskets may use different water passage shapes, port geometry, bolt patterns, or restricted/open flow layouts.

Do not select this gasket by engine displacement alone. Match the old gasket, manifold part number, elbow casting, and Crusader or Sierra parts diagram before installation.

When This Part Needs Replacement

Replace this gasket whenever the exhaust elbow, riser, or manifold joint is disassembled. It should also be replaced if there are signs of water leakage, exhaust soot tracking, rust trails, salt deposits, steam, overheating, corrosion around the joint, or suspected water intrusion at the exhaust elbow connection.

A used exhaust gasket should not be reused. Heat cycling, compression set, saltwater exposure, and corrosion can prevent the gasket from sealing properly after removal.

Installation Notes

Clean the manifold and elbow mating surfaces thoroughly before installing the new gasket. Remove old gasket material without gouging the sealing faces. Inspect the elbow, manifold, water passages, mounting bolts, threads, drain fittings, hoses, and clamps before reassembly.

Confirm that the gasket orientation and port openings match the cooling passage layout before tightening the elbow. Follow the Crusader or Sierra service procedure for bolt sequence, torque specification, and sealant guidance. Do not add sealant unless the service manual or gasket instructions specifically call for it.

Alternate/Cross-Reference Part Numbers

• Sierra Marine: 18-0305-1
• Crusader: 96108
• Related Sierra manifold references: 18-1925, 18-1926, 18-1929, 18-1933
• Common description: Exhaust Elbow Gasket / Manifold-to-Elbow Gasket

Parts Desk Insight

The critical check on this gasket is the exhaust passage layout. Crusader engines can share similar displacement names while using different manifold and elbow combinations. Before ordering, verify the manifold casting, old gasket shape, and cooling-system configuration so the replacement gasket routes water correctly and seals the exhaust joint properly.

Shipping: Ships same or next day for fast Canada wide shipping.