Engine Kits

Perfect Circle Piston Rings

Perfect Circle Piston Rings

MAHLE, manufacturer of Perfect Circle® piston rings, is the largest manufacturer of piston rings in the world, leads the way in ring technology and innovation. Perfect Circle rings are at the forefront of both light and heavy vehicle piston ring technology. Extensive OE connections mean that Perfect Circle rings have the technological edge. Things like the CP-20 oil ring, narrow compression rings, steel compression rings for gasoline engines, low tension oil rings and coated compression rings for diesels all came from the OE. Now, MAHLE’s rededication to the Perfect Circle performance line proves that Perfect Circle should be the ring choice under every hood - regardless of the application.

Until recently, grey cast iron or ductile iron was the material of choice for automotive applications - today, steel is preferred over iron by more and more engine designers. Steel compression ring technology, pioneered by the former Perfect Circle group, has been used in heavy-duty applications for over 30 years. That know how has become essential to the design and engineering of today's automotive engines.

Steel piston rings offer higher tensile strength, higher yield strength, greater fatigue life, and greater hardness while still offering a lower ring mass. These factors lead to better stress resistance, reduced groove pound-out, longer service life, better conformability, superior oil economy, and superior blow-by control while still lowering friction.

Whether you're repairing a modern computer controlled engine, or rebuilding an older engine, be sure to specify Perfect Circle piston rings - trusted by professional automotive technicians for over 100 years.

This product is in the following categories:

HomeEngine PartsPiston Rings


Perfect Circle

Part #: 40141CP

Perfect Circle Moly Ring Set 40141CP STD Size 400 SBC 4.125" Bore
Price: $37.77
Part #: 40203CP

Perfect Circle 40203CP 454 Chevy, 440 Dodge, STD Moly Ring
Price: $36.75
Part #: 40564CP

350 Chevy Moly Ring set
4.00" bore
5/64 5/64 3/16 Grove Size
Price: $28.90
Part #: 41137CP

Perfect Circle 41137CP Moly Ring Set for 305 Chevy STD
Price: $49.66
Part #: 41718

This ring set fits the following engines:
395 CID/6468CC 6.5L Diesel V8 1992-02 Chevy Truck
395 CID/6468CC 6.5L Chevy Diesel V8 1996-02 Hummer
Price: $99.99

Part #: 50141CP

Perfect Circle Cast Ring Set 50141CP STD Size 400 SBC 4.125" Bore
Price: $28.05
Part #: 50203CP

Perfect Circle 50203CP STD Ring Set Cast Big Block Chevy
Price: $23.15
Part #: 50564CP

Perfect Circle 50564CP Chevy 4" STD Bore
Buy 5 for $16.47 each and save 5%
Buy 15 for $14.74 each and save 15%
Buy 30 for $13.87 each and save 20%
Price: $17.34
Part #: 51137CP

Perfect Circle 51137CP Cast Ring Set for 305 CID Chevy
Price: $28.51