Product Description
MAHLE 41909.02 is a complete .020" (≈0.50 mm) oversize piston ring set for the 2001–2004 GM 6.6L Duramax LB7. Rings are pre-lapped for immediate seating, sold as a full engine set (8 cylinders), and built to OE specs for durability and oil control.
- Application: 6.6L Duramax LB7 (2001–2004)
- Oversize: .020" (≈0.50 mm) overbore
- Top ring: Ductile iron with plasma-moly face
- Second ring: Cast iron
- Oil ring assembly: GNS
- Ring thicknesses (axial): 3.0 mm / 2.0 mm / 3.0 mm
- Bore size: ~4.075"
- Set contents: Complete engine set (8 cylinders / 32 rings)
Note: .020" oversize requires matching .020" over pistons and a properly machined cylinder bore. Always verify ring width against your piston grooves.
Fitment
- 2001, 2002, 2003, 2004 Chevrolet Silverado 2500HD / 3500HD – 6.6L Duramax LB7
- 2001, 2002, 2003, 2004 GMC Sierra 2500HD / 3500HD – 6.6L Duramax LB7
Cross Reference / IDs
- MAHLE MPN: 41909.020 (also written as 41909020)
- UPC/GTIN: 027067460806
- Summit Racing P/N: MAH-41909020
Specs & Highlights
- OE-quality, pre-lapped rings for fast seal-up
- Plasma-moly top ring for high load durability
- Complete V8 set; engineered to factory tolerances
FAQ
Do these rings require a break-in?
The rings are pre-lapped for immediate seating and do not require a traditional break-in process.
Will these fit my LB7 if my block is still standard bore?
No. These are .020" oversize rings and require .020" over pistons and a matching overbore.
What ring thicknesses are included?
Nominal axial heights are 3.0 mm (top), 2.0 mm (second), and 3.0 mm (oil).
Is this the same part often listed for 2001–2010 Duramax?
Yes, the 41909.020 set is commonly cataloged for 2001–2010 Duramax. This listing is focused on 2001–2004 LB7; always verify piston groove widths and oversize before ordering.
