Piston Ring Set 4.170 .043 .043 3.0mm

The MAHLE PISTONS Piston Ring Set 4.170 .043 .043 3.0mm (Part No. 4170ML-043) is a precision-engineered ring kit designed for high-performance 8-cylinder engine builds requiring file-fit installation. This performance series ring set delivers the controlled compression and blow-by characteristics necessary for naturally aspirated and lightly boosted applications where precision ring fit and low tension operation are critical to engine longevity and power delivery.

Manufactured from ductile iron with plasma moly coating, these rings feature a 4.170-inch bore diameter and symmetric .043-inch top and second ring thicknesses combined with a 3.0mm oil control ring thickness. The low-tension design reduces parasitic drag on the crankshaft while maintaining effective sealing—a critical balance for small-block and big-block applications where ring friction directly impacts fuel economy and horsepower output. File fitting during installation ensures perfect ring gap and side clearance relative to your specific bore conditions, preventing blow-by and oil consumption that plague rings with looser tolerances. The plasma moly facing provides superior scuff resistance during engine break-in and sustained high-load operation.

This ring kit is engineered for engine builders and restorers who demand precision bore preparation, proper honing, and careful gapping and installation procedures. It's ideal for street engines, vintage muscle car restorations, and performance rebuilds where OEM or aftermarket block-hugger rings would compromise reliability. The 4.170ML-043 specification matches many classic small-block platforms and represents MAHLE's commitment to accurate bore sizing and controlled ring dynamics in the performance aftermarket.