21252233 Piston Ring Kit | Genuine Volvo Penta Part

🔧 Product Description

A genuine Volvo Penta standard-size piston-ring kit for one 101mm-bore Deutz-derived D4D / D6H engine piston. The three-ring pack restores combustion sealing, oil control and heat transfer for one cylinder. Four kits are required for a four-cylinder D4D / TAD420 engine and six kits for a six-cylinder TAD650 / D6H engine. Ring widths are approximately 2.5mm top, 2.0mm second and 3.0mm oil-control.

🚤 Compatibility

Typically suits:

• Volvo Penta TD420VE
• Volvo Penta TAD650VE
• Volvo Penta TAD420VE

• Engine Family: TD, TAD
• HP Range: Approximately 100-220 HP
• Year Range: Approximately 2000s - 2010s
• Serial Range: SN10642781-

⚙️ Key Features

• Genuine Volvo Penta standard 101mm piston-ring set
• Three-ring pack for one piston
• Approximate ring widths 2.5mm / 2.0mm / 3.0mm
• Four kits for four-cylinder engines; six for six-cylinder engines
• Engine type: Volvo Penta 4- or 6-cylinder Deutz-derived turbocharged industrial diesel
• 4 used per assembly

📋 Kit Contents

• 21252233 top compression ring - 1
• 21252233 second compression / scraper ring - 1
• 21252233 oil-control ring assembly - 1
• 21252233 complete standard-size ring pack for one 101mm piston - 1 set
• Volvo Penta does not assign separate service numbers to the individual rings; all are supplied under kit number 21252233
• Piston, pin, clips and cylinder liner are not included

🔌 Function

The rings seal combustion pressure, scrape excess oil from the cylinder wall and transfer piston heat into the liner.

⚠️ Common Signs of Failure

• Compression and engine power are low
• Crankcase blow-by or oil consumption increases
• Blue smoke or oily exhaust deposits are present
• Rings are broken, worn or carbon-stuck
• Cylinder bore and piston ring-groove clearances exceed specification

🛠️ Service Notes

• Check the end gap of each ring in the bore it will run in and compare it with the figure in the workshop manual for your engine; a worn or rebored cylinder changes it
• Fit the rings the right way up — where a face is marked or the section is stepped, that face goes towards the piston crown, and an oil control ring's expander must be fitted without overlapping its own ends
• Use a ring expander rather than levering rings on with a screwdriver, and open them only as far as they need to go; cast rings snap and the groove edges nick easily
• Stagger the ring gaps round the piston as the manual for your engine directs, so that no two gaps line up
• Oil the rings, bore and compressor lightly, enter the bore with a ring compressor, and never force the piston in — if it resists, back it out and find out why

🔄 Supersession & Cross Reference

OEM Supersession Chain

• 21252233 → Supersedes 20482739

OEM / Related Numbers

• 20850056 earlier number superseded by this part
• 20482739 earlier number superseded by this part
• 21797646 related reference
• Volvo Penta D4D / D6H piston and 101mm cylinder-liner components

Other-Brand OEM Numbers

• Kolbenschmidt: 800057310000
• MAHLE: 099 RS 00137 0N0 / 10191N0 - verify piston revision
• Mahle: 10191N0
• Goetze Engine: 08-127900-00

Aftermarket / Verified Equivalents

• NE: 120015005900
• Sync Parts: 01-1422
• VolvoKits: PRK-739

📦 Condition

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