21528663 Valve Seat | Genuine Volvo Penta Part

🔧 Product Description

Heat-resistant replaceable exhaust valve-seat insert for Volvo Penta D5/D8 industrial cylinder heads. It provides the sealing surface for the exhaust valve under high combustion and exhaust temperature and transfers valve heat into the cylinder head.

🚤 Compatibility

Typically suits:

• Volvo Penta TAD840GE
• Volvo Penta TAD841-43GE
• Volvo Penta TAD552VE
• Volvo Penta TAD853VE
• Volvo Penta TAD851-53GE
• Volvo Penta TAD880-82GE
• Volvo Penta TAD880-84VE
• Volvo Penta TAD580-83VE
• Volvo Penta TAD570-72VE
• Volvo Penta TAD570-71VE-B
• Volvo Penta TAD550-51VE
• Volvo Penta TAD540-42VE
• Volvo Penta TAD840-43VE
• Volvo Penta TAD850-52VE
• Volvo Penta TAD870-73VE
• Volvo Penta TAD840GE-B
• Volvo Penta TADH880-82GE
• Volvo Penta TADH880-84VE
• Volvo Penta TAD852VE-B

• Engine Family: TAD, TADH

⚙️ Key Features

• Genuine Volvo Penta exhaust valve-seat insert
• Heat-resistant hardened material
• Restores correct valve contact and compression sealing
• Requires specialist cylinder-head machining
• Engine type: Inline-six turbocharged industrial/generator diesel
• 8 used per assembly

🔌 Function

Provides the durable sealing and heat-transfer surface for the exhaust valve.

⚠️ Common Signs of Failure

• Burnt or leaking exhaust valve
• Seat recession or cracking
• Exhaust gas leakage during testing
• Uneven valve contact or excessive installed depth

🛠️ 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

Other-Brand OEM Numbers

• VOE21528663

Aftermarket / Verified Equivalents

• Olsson Parts: 51596

📦 Condition

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