20430463 Valve Seat | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta 0.20 mm oversize exhaust-valve seat for selected D12 cylinder heads. It is used when the exhaust-seat bore has been machined to the documented oversize repair dimension and is installed in place of standard exhaust seat 20412798.

🚤 Compatibility

• Engine Family: D, TAD

Full model list at the end of this description.

⚙️ Key Features

• Exhaust-valve seat in 0.20 mm oversize specification
• Twelve used in the applicable D12 cylinder head
• Alternative to standard exhaust seat 20412798
• Used with exhaust valve 20441486
• Requires professional cylinder-head machining and final seat cutting
• Engine type: Volvo Penta 12-litre six-cylinder diesel

🔌 Function

Provides the hardened sealing and heat-transfer surface for the exhaust valve after an oversize seat repair.

⚠️ Common Signs of Failure

• Loss of compression at the exhaust valve
• Valve-seat recession or cracking
• Poor seat contact after machining
• Burnt exhaust valve
• Seat bore outside standard repair dimension

🛠️ 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 / Related Numbers

• 20412798 - standard exhaust-valve seat
• 20441486 - exhaust valve
• 20459329 - standard inlet seat
• 20459332 - 0.20 mm oversize inlet seat
• 23134313 - related cylinder-head references
• 3803666 - related cylinder-head references
• 3803924 - related cylinder-head references

📦 Condition

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

🔎 Full Model Compatibility

Typically suits:

• Volvo Penta D12D-A MG, D12D-A MH, D12D-A MP, D12D-B MH, D12D-B MP, D12D-C MH, D12D-C MP, D12D-D MP, D12D-E MG, D12D-E MH, D12D-E MP, D12D-F MP, D12D-G MH, D12D-G MP, D12D-H MP
• Volvo Penta TAD1241VE, TAD1241-42VE
• Volvo Penta TAD1250VE, TAD1250-52VE
• Volvo Penta TAD1242VE
• Volvo Penta TAD1251VE
• Volvo Penta TAD1252VE