Sierra 18-1949 Marine Manifold Riser Spacer for Ford & GM V8 Engines

The Sierra 18-1949 Manifold Riser Spacer is a heavy-duty marine exhaust component designed to add height to exhaust risers and help prevent water from traveling back into the riser during throttle-down conditions. Installation of the spacer also provides additional clearance for exhaust hose routing, making it a practical solution for complex marine exhaust configurations.

Engineered for compatibility with a wide range of Ford and GM-based V8 marine engines, this spacer features CNC-machined mating surfaces that ensure a proper seal without the need for additional surface preparation. Sierra's special casting techniques produce uniform wall thickness throughout, and each spacer is 100% leak tested prior to painting to guarantee quality before it leaves the factory.

Key Features:

• Adds height to exhaust risers to reduce water back-flow risk at throttle-down
• Provides added clearance for exhaust hose routing
• CNC-machined mating surfaces for reliable, leak-free sealing
• Uniform wall thickness achieved through precision casting techniques
• 100% leak tested prior to paint for verified quality
• Primed and painted for corrosion resistance and long service life
• Ready to install out of the box
• Backed by SeaStar Solutions Limited Two-Year Warranty

Compatible Companion Parts:

• Exhaust Manifold: 18-1998-1
• Riser: 18-1907, 18-1939
• Elbow: 18-1999
• Exhaust Elbow Mounting Package: 18-4363

Cross-References: Replaces Barr FM-1-83 / FM183, GLM 56250, Mallory 9-40111, Osco FL994 / FLCR818. Also referenced as OEM number 20-0097.