477658 Valve Seat | Genuine Volvo Penta Part

🔧 Product Description

Genuine Volvo Penta valve seat from the Engine group in the oversize version, marked Over size, weighing 0.050 kg and listed for 16 applications across TWD, TD, TAMD and TAD series engines. It is the heavier of the two oversize seats here, with 477667 at 0.039 kg, and the standard equivalents are 477657 and 477659.

🚤 Compatibility

Typically suits:

• Volvo Penta TWD730ME
• Volvo Penta TWD731VE
• Volvo Penta TWD740GE
• Volvo Penta TWD740VE
• Volvo Penta TD730ME
• Volvo Penta TD730VE
• Volvo Penta TAMD75P-A
• Volvo Penta TAMD74P-A
• Volvo Penta TAMD74P-B
• Volvo Penta TAD740GE
• Volvo Penta TAD741GE
• Volvo Penta TAMD74A
• Volvo Penta TAMD74C-A
• Volvo Penta TAMD74C-B
• Volvo Penta TAMD74L-A
• Volvo Penta TAMD74L-B

• Engine Family: TWD, TD, TAMD, TAD

⚙️ Key Features

• Oversize version, marked Over size
• 0.050 kg, the heavier of the two oversize seats against 477667 at 0.039 kg
• 16 applications across TWD, TD, TAMD and TAD engines
• Standard equivalents are 477657 and 477659

🔌 Function

Forms the hardened sealing ring the valve closes against, sealing the combustion chamber and conducting heat from the valve into the head.

⚠️ Common Signs of Failure

• Compression loss with poor starting and a misfire on one cylinder
• Hissing from the inlet or exhaust when cranking
• Seat face burnt, pitted or recessed
• Seat loose in an already machined recess
• Valve stem or head showing heat damage

🛠️ Service Notes

• Only fit oversize once the recess has been machined to suit, and measure before ordering
• The published details do not say which of the two oversize seats is inlet and which is exhaust, so order by number after measuring
• Seat cutting and valve recession checks are machine shop work

📦 Condition

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