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Piston Rings
- Porsche 964 (911) TURBO 3.6L 1991-93
Genuine Porsche Piston Ring Set.
Sold each - 6 required per car
Fits
- Porsche 964 Turbo 3.6L 1993 (M64.50)
What This Product Does
Installed within the grooves around the piston, the rings form the working seal between the piston and cylinder. They retain combustion pressure, manage the lubricating-oil film and conduct heat away from the piston.
Functions
- Maintains the seal around the combustion chamber
- Regulates oil remaining on the cylinder surface
- Reduces gas blow-by into the crankcase
- Conducts heat from the piston towards the cylinder
Technical Details
- Part number: PCG50399N0
- Supply quantity: one ring set for one piston
- Size specification: standard
- Engine applications: M64.50
A complete six-cylinder engine normally requires six individual sets. Confirm the quantity needed for the planned rebuild before ordering.
Symptoms of Fault
- Rising engine-oil consumption
- Blue smoke from the exhaust under acceleration
- Low or inconsistent compression readings
- Increased crankcase pressure and blow-by
- Oil deposits on spark plugs
- Loss of power associated with poor cylinder sealing
Similar symptoms may be caused by worn cylinders, damaged pistons, valve-guide wear or crankcase-ventilation faults. Compression and leak-down testing should form part of the diagnosis.
Why Replacement Matters
Damaged, worn or seized rings can compromise compression and oil control. When rebuilding the engine, inspect the pistons, ring grooves and cylinder running surfaces for wear, scoring and dimensional accuracy. Cylinder condition, ring end gaps, installation direction and operating clearances must comply with the applicable Porsche workshop specifications.
FAQs
- Does one set cover the complete engine?
No. This product contains rings for one piston; six sets are generally required for the complete six-cylinder engine. - Are these oversized piston rings?
No. The supplied rings are standard size for a nominal 100 mm bore. - Should the cylinders be checked before fitting?
Yes. Measure each bore and inspect its surface finish to establish whether standard-size components remain suitable. - Can rings be renewed without inspecting the pistons?
No. The piston grooves, lands and related cylinder surfaces should be assessed as part of the rebuild.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
PCG50399N0
The product you are viewing cross references to these numbers
Piston Rings – Precision Engine Sealing & Performance for Porsche Models
The piston rings in your Porsche engine are critical components that maintain compression, regulate oil consumption, and ensure efficient combustion. Positioned around the pistons, they create a tight seal between the piston and cylinder wall, keeping combustion gases contained while allowing smooth piston movement.
At Design911, we supply a comprehensive range of piston rings designed for both classic and modern Porsche engines. Manufactured from high-strength, heat-resistant materials, these rings deliver exceptional sealing, reduced friction, and long-term reliability. Whether you’re performing a full engine rebuild or a top-end refresh, our quality piston rings are engineered for perfect fitment and optimum performance.
What Do Piston Rings Do?
Piston rings perform three vital functions within the
engine:
- Sealing
the combustion chamber – to prevent gas leakage and maintain
compression.
- Controlling
oil consumption – by scraping excess oil from the cylinder walls.
- Conducting heat – transferring it from the piston to the cylinder wall to prevent overheating.
These rings are essential for maintaining engine
efficiency, power output, and longevity. Properly functioning piston rings
ensure consistent compression, clean emissions, and smooth performance.
Why Do Piston Rings Fail?
Piston rings are subject to intense heat, pressure, and friction. Over time, these conditions can lead to wear, loss of sealing ability, or even engine damage.
Common Causes of Piston Ring Failure Include:
- Excessive
wear or scoring from poor lubrication or debris.
- Carbon
build-up causing sticking or uneven sealing.
- Overheating
that leads to ring warping or loss of tension.
- Corrosion
or fatigue from oil contamination.
- Improper installation during rebuilds or maintenance.
Symptoms of worn piston rings include blue exhaust smoke, loss of compression, reduced performance, or excessive oil consumption — all signs that replacement is required.
Why Replace Piston Rings?
Replacing worn or damaged piston rings restores compression, improves combustion efficiency, and protects your Porsche engine from further wear. Our high-performance piston rings are built to withstand extreme conditions, ensuring consistent sealing and reduced friction.
Key Benefits:
- Restores compression and engine power.
- Reduces oil consumption and exhaust smoke.
- Improves fuel efficiency and combustion quality.
- Constructed from durable, heat- and corrosion-resistant alloys.
- Direct-fit
compatibility for a wide range of Porsche models.
- Ideal for rebuilds, restorations, or performance upgrades.
Investing in premium-quality piston rings ensures lasting performance, smoother running, and optimal engine reliability.
Highlights:
- Precision-engineered piston rings for Porsche engines.
- Restores compression, performance, and oil control.
- Made from high-strength, wear-resistant materials.
- Perfect fit for classic and modern Porsche models.
- Essential for rebuilds and long-term engine health.
- Ensures smooth, efficient combustion and lower emissions.