Sierra 18-1998-1 Exhaust Manifold, White, Cross-Reference Barr FM-1-83

The Sierra 18-1998-1 is a marine exhaust manifold finished in white with a machined exterior, engineered as a direct replacement for worn or corroded factory manifolds. Exhaust manifolds route hot exhaust gases away from the engine block while a surrounding water jacket cools the exhaust and the engine, and a compromised manifold can lead to overheating, exhaust leaks, or water intrusion into the engine. The Sierra 18-1998-1 is built to restore that cooling and exhaust path with OEM-equivalent fit and function.

This manifold is designed to work with the Sierra 18-2854-1 elbow gasket for open riser setups or the 18-0476-1 elbow gasket for blocked riser setups, and pairs with the Sierra 18-1949 manifold spacer. It is cross-referenced to Barr FM-1-83, FM183, GLM 56250, Mallory 9-40111, Osco FL994, and Osco FLCR818, making it a suitable replacement wherever those part numbers are specified. The kit includes an exhaust elbow gasket, an 18-0183-1 exhaust manifold gasket, and an 18-4258 pipe plug, giving installers the gaskets and hardware needed to complete the swap without sourcing separate gasket kits.

Specifications

• Brand: Sierra
• Manufacturer Part Number: 18-1998-1
• Product Type: Exhaust Manifold
• Color: White
• Exterior Finish: Machined
• Weight: 36.11 pounds
• Product Dimensions: 0.39 x 0.39 x 0.39 inches
• UPC: 808282243340
• Category: PleasureCraft Exhaust Manifolds
• Compatible Riser Gasket (Open): 18-2854-1
• Compatible Riser Gasket (Blocked): 18-0476-1
• Compatible Manifold Spacer: 18-1949
• Kit Contents: Exhaust elbow gasket, 18-0183-1 exhaust manifold gasket, 18-4258 pipe plug

Replaces (OEM)

• Barr FM-1-83
• FM183
• GLM 56250
• Mallory 9-40111
• Osco FL994
• FLCR818

Frequently Asked Questions

What does the Sierra 18-1998-1 manifold replace? The Sierra 18-1998-1 exhaust manifold is cross-referenced to Barr FM-1-83, FM183, GLM 56250, Mallory 9-40111, Osco FL994, and FLCR818, so any of those part numbers can be replaced with this manifold.

What color and finish does this manifold come in? It comes in white with a machined exterior finish.

How much does the Sierra 18-1998-1 weigh? The manifold weighs 36.11 pounds.

What gaskets are needed to install the 18-1998-1 manifold? Use the Sierra 18-2854-1 elbow gasket for an open riser setup or the 18-0476-1 elbow gasket for a blocked riser setup with the 18-1998-1 manifold.

Does the manifold come with any gaskets or hardware included? Yes, the 18-1998-1 kit includes an exhaust elbow gasket, an 18-0183-1 exhaust manifold gasket, and an 18-4258 pipe plug.

Is a manifold spacer required with this part? The 18-1998-1 manifold is designed to work with the Sierra 18-1949 manifold spacer.

Is the Sierra 18-1998-1 an OEM or aftermarket part? The 18-1998-1 is a Sierra-manufactured manifold built as a direct cross-reference replacement for Barr FM-1-83 and the other listed OEM equivalents, rather than a part sourced from the original engine builder.

What is the exhaust elbow gasket used with the 18-1998-1 called? The open-configuration elbow gasket paired with the 18-1998-1 manifold is the 18-2854-1; the blocked-configuration version is the 18-0476-1.

Can this manifold be used with a blocked riser configuration? Yes, when running a blocked riser setup, pair the 18-1998-1 manifold with the 18-0476-1 elbow gasket instead of the open-configuration 18-2854-1.

What are the listed dimensions of the 18-1998-1 manifold package? The Sierra 18-1998-1 is listed at 0.39 x 0.39 x 0.39 inches.

What UPC is associated with the Sierra 18-1998-1 manifold? The UPC for the Sierra 18-1998-1 manifold is 808282243340.