21087847 Valve Seat | Genuine Volvo Penta Part

🔧 Product Description

Brand-new genuine Volvo Penta standard-size exhaust valve-seat ring for Volvo D9A/D9B-derived marine and industrial cylinder heads. The hardened insert is machined into the cylinder head and provides the heat-resistant sealing surface for the exhaust valve. It has an outside diameter of approximately 40.07 mm and must be installed and finish-machined by a qualified engine machine shop.

🚤 Compatibility

Typically suits:

• Volvo Penta TAD952VE
• Volvo Penta TAD951VE
• Volvo Penta TAD950VE

• Engine Family: TAD

⚙️ Key Features

• Standard-size exhaust valve-seat ring
• Approximate outside diameter: 40.07 mm
• High-temperature hardened material for exhaust-valve service
• Requires interference-fit installation and final concentric machining
• One seat supplied; valve, guide and stem seal are separate
• Engine type: Volvo Penta 9.4-litre inline six-cylinder diesel

🔌 Function

Provides the replaceable heat-resistant sealing face against which the exhaust valve closes, maintaining compression and transferring valve heat into the cylinder head.

⚠️ Common Signs of Failure

• Low compression or cylinder leakage through the exhaust valve
• Burnt, recessed or cracked valve seat
• Repeated valve-clearance reduction
• Hard starting, misfire or loss of power
• Exhaust-valve damage caused by poor seat contact

🛠️ 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

• 20528265 - Earlier standard exhaust-seat reference associated with the same D9 family

Other-Brand OEM Numbers

• VOE21087847

Aftermarket / Verified Equivalents

• LASO 9805 3226
• SLP VS-847
• Swedish Lorry Parts: VS-847

📦 Condition

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