21418352 Valve Seat | Genuine Volvo Penta Part

🔧 Product Description

Replaceable hardened exhaust-valve seat insert for Volvo Penta D9 cylinder heads. It withstands high exhaust temperature and provides the precision sealing and heat-transfer surface required by the exhaust valve on D9A2 and TAD9 engines.

🚤 Compatibility

Typically suits:

• Volvo Penta D9A2L MH
• Volvo Penta D9A2M MP

• Engine Family: D

⚙️ Key Features

• Genuine Volvo Penta exhaust valve-seat insert
• High-temperature hardened seat for D9 cylinder heads
• Supersedes earlier Volvo reference 20555104
• Requires professional cylinder-head machining and installed-height control
• Engine type: Volvo Penta D9 inline six-cylinder diesel

🔌 Function

Seals the exhaust valve during compression and combustion and transfers valve heat into the cylinder head between exhaust events.

⚠️ Common Signs of Failure

• Burnt exhaust valve or low compression
• Pitting, cracking or recession of the seat
• Excessive valve-clearance change
• Exhaust leakage, misfire or loss of power
• Loose seat insert or heat damage found during overhaul

🛠️ Service Notes

• Seat inserts are an interference fit in the head, so the counterbore has to be clean, round, flat and square before a new seat goes in; normal practice is to chill the insert and warm the head so it drops into place rather than forcing it
• This is machine-shop work — the seat must be cut concentric with the valve guide after installation, so check or renew the guides at the same time and cut the seat angles once the insert is secure
• Inspect the head casting for cracks and for a pounded or spread counterbore before committing to a new seat; a seat that has come loose has usually damaged its pocket
• Use the interference fit, insert size and seat angles specified for your engine rather than any general figure, as they differ between heads
• Check each valve on its finished seat for an even contact band right the way round, and confirm valve position and any permitted recession against the workshop manual for your engine

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21418352 → Supersedes 20555104

OEM / Related Numbers

• 20555104 earlier number superseded by this part
• 21418343 - corresponding intake-valve seat; not interchangeable

Aftermarket / Verified Equivalents

• SLP: VS-352
• SRP: VS-18352
• DT Spare Parts: 2.10540
• Auger: 100945
• Sampa: 037.490
• LASO: 9805 3219

📦 Condition

• Genuine Volvo Penta part
• Brand new
• Supplied in original or equivalent packaging