Description
Technical Overview & Product Details
Exhaust valve seats are subjected to the most severe environment in any diesel engine: high-velocity, high-temperature combustion gases. The Yanmar 146673-11090 seat is designed to manage this intense heat flux effectively. By providing a stable contact surface for the exhaust valve, it ensures that heat is drawn away from the valve head into the water-cooled cylinder head, preventing thermal fatigue and valve guttering.
The 146673-11090 is manufactured from specialized, high-alloy materials selected for their hot-hardness and resistance to “seat recession” caused by continuous hammering and abrasive exhaust particles.
- Compatible Engine Type: Yanmar 6N18 (A)L-V series marine propulsion and auxiliary engines.
- Part Number / Designation: 146673-11090.
- Component Type: Exhaust Valve Seat.
- Material: Premium heat-resistant tool steel alloy, hardened to resist thermal stress and chemical corrosion from high-sulfur marine fuels.
- Application: Exhaust outlet port of the cylinder head.
Key Features & Performance
- Superior Hot-Hardness: Engineered to maintain its dimensional stability and surface hardness even at elevated operating temperatures, preventing the seat from deforming or “sinking” into the cylinder head over thousands of running hours.
- Optimized Thermal Conductivity: The material composition is optimized to facilitate rapid heat transfer, acting as a thermal bridge that protects the exhaust valve from overheating, which is the primary cause of valve failure in medium-speed marine engines.
- Corrosion & Pitting Resistance: Specially treated to withstand the chemical attack of exhaust gases and the abrasive action of carbon deposits, ensuring a durable, long-term seal.
- Precision Geometry: Manufactured with strict adherence to Yanmar’s tolerances to ensure a perfectly concentric seat, which is essential for uniform pressure distribution and long-lasting valve performance.
Why Source from Heybeli Marine?
A failing exhaust valve seat leads to rapid valve wear, loss of engine power, and catastrophic damage if the valve seat becomes loose. Heybeli Marine safeguards your operations with:
- Strict OEM Interchangeability: Our 146673-11090 seats are fully interchangeable with original Yanmar components, ensuring seamless integration during major overhauls.
- Global Strategic Logistics: We maintain a deep stock of critical exhaust train components, allowing for rapid shipment to shipyards and vessels worldwide to minimize downtime during planned or emergency maintenance.
- Quality Assurance: Every batch undergoes material composition analysis and precise dimensional checks to ensure they meet the rigorous demands of the Yanmar 6N18 series.
- Complete Overhaul Support: We supply these seats alongside high-temperature exhaust valves, valve stem seals, and specialized locking components to provide a total solution for your engine maintenance needs.
Technical Maintenance Note:
Because the exhaust valve seat operates at significantly higher temperatures than the suction seat, the clearance fit during installation is critical. When fitting the 146673-11090, always ensure the seat and cylinder head are at the manufacturer’s specified temperatures to achieve the correct interference fit. After the seat is pressed into the cylinder head, we strongly recommend a final seat grinding or lapping procedure to ensure a perfect 360-degree contact pattern with the exhaust valve. Always replace the valve and seat as a matched set during an overhaul for optimal service life.