Yanmar N18 Valve Seat
Mega Marine supplies genuine and reconditioned valve seat for Yanmar N18 marine engines, along with complete engines and a comprehensive range of spare parts. Fast RFQ response and global delivery.
The valve seat insert is a hardened alloy ring pressed or thermally shrunk into the cylinder head, providing the precision-machined seating surface against which the exhaust valve spindle closes. Manufactured from heat-resistant alloys with Stellite or similar hard-facing on the contact surface, valve seats are designed as replaceable components during cylinder head overhaul.
Function in the Engine
Provides a replaceable hardened seating surface for the exhaust valve spindle, withstands repeated high-energy impact loading as the valve snaps shut, maintains a gas-tight seal despite extreme thermal cycling and aggressive combustion deposits.
About the Yanmar N18
Yanmar N-series 180mm bore medium-speed engine for propulsion and auxiliary applications in smaller commercial vessels.
Common Issues Requiring Replacement
Erosion and pitting of the seat face from hot combustion gas leakage, fretting corrosion of the press-fit interface causing loosening in the head, seat recession over time changing valve lift and timing, corrosive attack from vanadium pentoxide and sulfuric acid in heavy fuel combustion residues.
Mega Marine supplies genuine OEM and quality reconditioned valve seat for Yanmar N18 engines, with full traceability and global shipping to any port worldwide. We respond to quote requests within 4–6 hours.
- Engine Brand
- Yanmar
- Engine Model
- N18
- Part Category
- Valve Seat
- Condition
- Genuine & Reconditioned
Browse the full N18 parts range.
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