1378645 Cylinder Head Gasket | Genuine Volvo Penta Part

🔧 Product Description

This is the cylinder head gasket for Volvo Penta AQ-series and BB-series four-cylinder petrol marine engines, part of the engine system group. It forms the sealing joint between the cylinder head and the engine block, containing combustion pressure while keeping coolant and oil passages separate. This current-issue gasket supersedes earlier part number 463412 and carries its applications forward.

🚤 Compatibility

• HP Range: Approximately 120-145 HP
• Year Range: Approximately 1977 - 1985

⚙️ Key Features

• OEM Volvo Penta part number 1378645
• System group: Engine
• Supersedes previous part number 463412
• Net weight approximately 0.09 kg
• Fits AQ and BB series four-cylinder petrol marine engines
• Engine type: Volvo Penta B21 / B23 inline 4-cylinder 8-valve petrol engine

🔌 Function

The cylinder head gasket seals the mating surfaces of the cylinder head and cylinder block so combustion pressure is retained within each cylinder. It also isolates the coolant and oil galleries that cross the joint, preventing them from mixing or leaking externally.

⚠️ Common Signs of Failure

• Coolant loss with no visible external leak, or coolant appearing in the engine oil
• White exhaust smoke or a sweet smell from the exhaust indicating coolant entering a cylinder
• Loss of compression, rough running or misfire on one or more cylinders
• Combustion gases pressurising the cooling system, causing bubbling in the expansion tank or overheating
• Oil or coolant seepage along the head-to-block joint, or visible scorching and blow-out tracks on the gasket edge

🛠️ Service Notes

• Establish why the old gasket failed before fitting a new one — overheating, a distorted or cracked head, a corroded block face or a stretched fastener will destroy the new gasket in the same way
• Have the head and block faces checked for flatness and for the surface finish the gasket requires; clean them with plastic or hardwood scrapers and solvent rather than power tools or abrasives, which round the edges of the joint and drop grit into the bores
• Make sure both faces, the bolt holes and the coolant passages are clean and dry, and wipe or blow debris out of the cylinders before the head goes on
• Fit the gasket dry and the right way round, following any orientation marking on it, and use no sealant or jointing compound unless the workshop manual for your engine specifically calls for it
• Use new head bolts wherever the manual requires them — many are designed to stretch and cannot be reused — and tighten in the sequence, stages and angles the manual gives, then carry out any re-tension or valve clearance check it specifies

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 1378645 → Supersedes 463412

OEM / Related Numbers

• 463412 earlier number superseded by this part

Other-Brand OEM Numbers

• Victor Reinz: 61-24490-30
• Elring: 586.579

Aftermarket / Verified Equivalents

• Sierra: 18-2968
• GLM: 36080
• Recmar: REC1378645
• Orbitrade: 13645
• Corteco: 414960P
• Ajusa: 10021200

📦 Condition

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