3863450 4" Exhaust Bellows Hose for OMC Cobra Volvo Penta V4 V6 Boat Engine | Compatible with Marine 3.0L 4.3L 5.7L Stern/Out Drives, Replaces 3852741, 911741, 913591, Sierra 18-2780, Mallory 9-72814

Marine exhaust hoses serve as flexible connectors between engine exhaust ports and fixed piping systems. They absorb engine vibrations, compensate for thermal expansion and contraction, and accommodate minor installation deviations while ensuring the exhaust passage remains sealed.
Compatible with Volvo Penta Engines 3852741 3863450 3.0L 4.3L 5.7L for Sierra 18-2780 For Mallory 9-72800 9-72814 for GLM 89222
Compatible for Volvo Penta 3.0L GL GS GI GLM GLP GSM GSP GS; 4.3L GL GS GI GXI OSI; 5.0L FL FI GL GXI OSI; 5.7L GL GI GXI OSI OSXI GIL GXIL; 5.8L FL FI FSI; 7.4L GL GI GSI; 8.2L GSI.
The bellows are constructed from rubber material, maintaining structural integrity when exposed to dry exhaust gases within a temperature range of 120-150°C (250-300°F). This material exhibits properties such as heat aging resistance, ensuring unobstructed airflow and long-term durability.
A distinguishing feature of early 5.7L GM-based units is a reinforced protrusion on the bellows, a design revised in subsequent production. To ensure correct fitment, a visual inspection of your current component is advised prior to purchase.

Product Description: Exhaust Bellows HoseCompatible with Volvo Penta Engines 3852741, 3863450, 3.0L, 4.3L, 5.7L. Also fits Sierra 18-2780 and Mallory 9-72800, 9-72814.1. Product OverviewThis exhaust bellows hose is a critical component within the wet exhaust system of marine inboard gasoline engines. It serves as a flexible, sealed conduit connecting the engine's exhaust manifold or elbow to the downstream fixed section of the exhaust piping.Vibration Dampening:Absorbs engine vibrations to prevent stress-induced damage to exhaust components.Thermal Compensation: The flexible design accommodates heat expansion and contraction of metal parts.Leak Prevention: Maintains a critical gas-tight seal, safely directing toxic exhaust gases overboard.Alignment Tolerance:Allows for minor installation misalignments between the engine and fixed piping.2. Construction & FeaturesHeat-Resistant Rubber Hose: The main body is constructed from a reinforced synthetic rubber composite material, capable of withstanding sustained exposure to high temperatures and exhaust gases (120°C - 150°C / 250°F - 300°F).Flexible Corrugated Structure: This design enables the hose to compress, expand, and bend freely, effectively absorbing displacement caused by engine movement, vibration, and thermal expansion.3. Installation, Maintenance, and Critical PrecautionsPre-installation Inspection: Before installation, conduct a thorough visual and tactile inspection of the new bellows hose. Confirm the surface is free of defects, cuts, cracks, or deformation. Simultaneously, verify that the mating surfaces on the engine and exhaust pipe are clean, smooth, and free of residual old gaskets or corrosion that could compromise sealing integrity.