Piston Ring Kit – Fits Volvo Penta MD21/AQD21/MD32/AQD32 (Replaces 876161)
Piston Ring Kit – Fits Volvo Penta MD21/AQD21/MD32/AQD32 (Replaces 876161) is backordered and will ship as soon as it is back in stock.
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Worry-free returns
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Delivery and Shipping
Delivery and Shipping
Free standard shipping on all orders under 1 KG
Piston Ring Kit – Fits Volvo Penta MD21/AQD21/MD32/AQD32 (Replaces ...
Product Details
This aftermarket Piston Ring Kit is designed for Volvo Penta diesel engines from 1975–1987, including the 4-cylinder MD21A, MD21B, AQD21A, and AQD21B models, as well as the 6-cylinder MD32 and AQD32 series. Each kit provides the standard (STD) size rings required for an original engine bore specification.
This kit serves as a direct replacement for Volvo Penta part number 876161 and Orbitrade 11161, ensuring a precise fit and reliable performance.
- Installation requires engine-specific knowledge and following the service manual.
- Engineered for use in marine diesel applications.
- Constructed from high-grade steel for durability and longevity.
Part Number Matrix
Use this matrix to confirm equivalent references across OEM and aftermarket.
| Brand | Part Number |
|---|---|
| Volvo Penta | 876161 |
| Orbitrade | 11161 |
Engine & Model Compatibility
Confirm your engine model/year in the table below.
For Volvo Penta 4-cylinder engines (MD21/AQD21 series), four kits are required. For 6-cylinder engines (MD32/AQD32 series), six kits are required.
| Brand | Model | Stroke | OEM Part No. | Notes |
|---|---|---|---|---|
| Volvo Penta | MD21A | 4-Stroke | 876161 | 4 pieces required per engine |
| Volvo Penta | MD21B | 4-Stroke | 876161 | 4 pieces required per engine |
| Volvo Penta | AQD21A | 4-Stroke | 876161 | 4 pieces required per engine |
| Volvo Penta | AQD21B | 4-Stroke | 876161 | 4 pieces required per engine |
| Volvo Penta | MD32 | 4-Stroke | 876161 | 6 pieces required per engine |
| Volvo Penta | AQD32A | 4-Stroke | 876161 | 6 pieces required per engine |
Technical Specs
- Product Type
- Piston Ring Kit
- Fuel Type
- Diesel
- Housing Material
- High-grade steel
- Dimensions
- 12.6 x 12.6 x 1.8 in
- Weight
- 0.167 to 1 lbs (0.076 to 0.45 kg)
- Bore Size
- Standard (STD) size for original bore specification
What’s in the Box
- 1 x Piston Ring Kit (876161) - Contains 4 piston rings which fit around the top of each piston to make it gas tight.
Installation Notes
- Disconnect the battery and safely drain all engine fluids, including oil and coolant.
- Remove the cylinder head and oil pan to gain access to the pistons and connecting rods.
- Carefully extract the pistons from the cylinders.
- Using a piston ring expander tool, remove the old rings from each piston.
- Thoroughly clean the piston ring grooves to remove all carbon buildup and debris.
- Install the new piston rings onto the pistons in the correct order and orientation as per your engine's service manual.
- Generously lubricate the new rings, pistons, and cylinder walls with fresh engine oil.
- Reinstall the pistons and reassemble the engine, ensuring all bolts are tightened to the manufacturer's specified torque values.
Troubleshooting & FAQ
How many kits do I need for my engine?
Four-cylinder engines (MD21A, MD21B, AQD21A, AQD21B) require four (4) kits. Six-cylinder engines (MD32, AQD32) require six (6) kits. Each kit services one piston.
What are the common signs of failing piston rings?
Symptoms of worn or damaged piston rings include excessive oil consumption, blue or gray exhaust smoke, loss of engine power, and poor compression. A compression test can help diagnose the issue.
Is this a standard (STD) size kit?
Yes, this kit is for standard size bores. It is not suitable for engines that have been bored out to an oversized specification.
Why is there a weight discrepancy listed?
The weight can vary based on packaging and whether the source lists the weight of a single kit or a full engine set. The provided weight range (0.167 to 1 lbs) reflects these differences. The actual part weight is on the lower end of this range.
OEM vs. Aftermarket?
This listing is an aftermarket replacement (not OEM). Built to OEM-level specifications with comparable materials. Manufactured in an ISO 9002 facility, batch-inspected for consistency.
Shipping speed & cost
We ship worldwide quickly—typical transit 5–15 days. Standard shipping is free; expedited options appear at checkout where available.
Warranty & returns
Covered by a 1-year warranty against manufacturing defects under normal use. If issues arise, contact support with your order details. Returns are accepted within our standard window (unused & in original condition). See our policy page or reach out for instructions.
Safety & Important Info
- Verify images/specifications vs your original part. If anything differs—even if your model appears compatible—do not purchase.
- This is an aftermarket replacement, not an OEM component.
- Professional installation is recommended for safety and performance.
About Sea Sierra
- Pro-Grade Standards — We supply marine parts engineered to OEM-level tolerances and tested for real-world conditions.
- Fast Global Fulfillment — Free standard delivery to most regions in 5–15 days.
- Manufacturer-Direct Value — Fair pricing without compromising on materials or QC.
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