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Vehicle Info NeededPlasma-Moly Standard Tension Piston Ring Set with 4.045" Bore
Ships on 10/12/2026
Lowest Price Guarantee- Plasma-Moly Piston Ring Set
- 4.045" Bore (+.045")
- 5/64", 5/64", 3/16" Ring Widths
- File Fit
- Standard Tension
- Reduced Radial Wall
- Ductile Iron
Radial: - Top Ring Radial: .187"
- Second Ring Radial: .187"
- Oil Ring Radial: .201"
MAHLE Original plasma-moly ductile ring sets are designed for the serious racer. These sets feature rings that maximize combustion sealing and minimize frictional losses to increase horsepower and oil control. These sets include reduced radial wall top rings, and CP-20 oil rings to reduce tension, improve conformability and maximize power output. Ring sets with low and ultra low tension oil rings are not recommended for street use and should utilize a vacuum pump for maximum performance.
Mahle Original performance piston rings sets are the most technically advanced and rigorously tested than any other piston ring manufacture. Current racing engines demand piston rings to operate at higher operating rpm, higher compression ratio, and higher temperatures from race to race and remain dependable. These factors require rings that are stronger, lighter, seals better, and resist wear under extreme conditions.
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Features:
- Recommended for street, racing, or marine applications
- Barrel faced top ring offers instant break-in and maintains contact with the cylinder wall as the piston rocks slightly at TDC and BDC.
- Napier THG (hook groove) second compression ring provides superior oil control by scraping cylinder walls of oil and providing a reservoir on each down stroke.
- CP-20 oil control ring, named by its 20 degree ear angle, and exclusive feature that provides the absolute best cylinder wall seal.
- Available in different compression ring materials consisting of cast iron, ductile iron, gas nitride stainless steel, steel alloy.
High Alloy Steel vs. Ductile Iron
Physical Advantages:
- Higher Tensile Strength
- Higher Yield Strength
- Greater Fatigue Resistance
- Greater Hardness
- Lower Ring Mass
Performance Benefits:
- Better Stress Resistance
- Reduced Groove Poundout
- Less Side Wear
- Superior Oil Economy
- Superior Blow-by Control
- Lower Friction
- Longer Service Lift
- Better Cylinder Wall Conformability
