MAHLE S42246.030 Moly Piston Ring Set +.030 for 11-Up Navistar MaxxForce 7 6.4L

Vehicle Fitment

• 2011-Up International 4300 (Navistar MaxxForce 7 6.4L V8 Diesel - CGI Block)
• 2011-Up International 4400 (Navistar MaxxForce 7 6.4L V8 Diesel - CGI Block)
• 2011-Up International DuraStar / WorkStar / TerraStar equipped with the MaxxForce 7 6.4L V8 Diesel
• All Navistar/International medium-duty applications using the 2011-up MaxxForce 7 compacted graphite iron (CGI) block V8 diesel

Fitment Notes

• This is a +.030-Inch (.030" / 0.762mm) oversize ring set - for use only with cylinders bored or honed to +.030" oversize
• Verify bore diameter with a bore gauge before ordering - do not use oversize rings in a standard-bore cylinder
• Sold as a single-cylinder ring set (rings for 1 piston); order the quantity of cylinders being rebuilt
• For standard bore applications, see MAHLE S42246 (STD)
• For +.010" oversize, see MAHLE S42246.010; for +.020" oversize, see MAHLE S42246.020; for +.040" oversize, see MAHLE S42246.040
• Applies to the 2011-up MaxxForce 7 CGI block - not for use with the 2008-2010 Ford 6.4L Power Stroke application

Features

• Plasma-moly faced upper compression ring provides superior wear resistance and scuff protection under the high cylinder pressures generated by turbocharged diesel engines
• Carbon steel upper compression ring (UCR) construction delivers excellent strength and fatigue resistance at 1.2mm axial height for reduced friction and improved oil control
• Cast iron lower compression ring (LCR) at 1.5mm axial height provides efficient gas sealing and long service life using the THM-10 taper-face design
• Three-piece stainless steel oil control ring (OCR) with chrome-faced rails and CP-20 expander maintains precise oil film control at 2.5mm axial height
• Pre-lapped ring surfaces streamline installation and ensure immediate break-in contact with the cylinder wall from the first start
• OE-quality construction meets or exceeds Navistar original equipment specifications for sealing, oil control, and ring groove fit
• Compensated ring groove design ensures proper ring loading and controlled radial pressure throughout service life
• MAHLE OE supply heritage - MAHLE is one of the world's largest original equipment piston ring manufacturers, supplying rings directly to engine OEMs globally

Specifications

• Part Number: S42246.030
• Brand: MAHLE Original
• Part Type: Single-Cylinder Piston Ring Set
• Oversize: +.030-Inch (0.762mm)
• Engine Application: Navistar MaxxForce 7 6.4L V8 Diesel (2011-Up CGI Block)
• Upper Compression Ring (UCR) - Material: Carbon Steel | Facing: Plasma-Moly | Axial Height: 1.2mm | Type: RF-13PFD
• Lower Compression Ring (LCR) - Material: Cast Iron | Facing: N/A | Axial Height: 1.5mm | Type: THM-10
• Oil Control Ring (OCR) - Material: Stainless Steel | Facing: Chrome | Axial Height: 2.5mm | Type: CP-20
• Quantity: Single-Cylinder Set (3 Rings - UCR, LCR, OCR Assembly)

Included Components

• 1x Upper Compression Ring (UCR) - Carbon Steel, Plasma-Moly, 1.2mm, RF-13PFD
• 1x Lower Compression Ring (LCR) - Cast Iron, 1.5mm, THM-10
• 1x Three-Piece Oil Control Ring Assembly (OCR) - Stainless Steel, Chrome-Faced Rails, CP-20 Expander, 2.5mm

Product Description

The MAHLE S42246.030 is a +.030-inch oversize single-cylinder piston ring set engineered for the Navistar MaxxForce 7 6.4L V8 diesel engine in 2011-and-later International medium-duty truck applications. This ring set covers the updated MaxxForce 7 compacted graphite iron (CGI) block platform introduced for the 2011 model year, which brought significant block strength improvements over the earlier 2008-2010 cast iron block version. The S42246.030 is intended for use in cylinders that have been bored or honed to +.030" oversize as part of an engine rebuild - the bore must be measured with a bore gauge before ordering to confirm the correct oversize is selected.

The ring set uses a three-ring configuration consistent with MAHLE's heavy-duty diesel specifications. The upper compression ring (UCR) is a 1.2mm carbon steel ring with a plasma-moly face using the RF-13PFD barrel-face design, providing the wear resistance and scuff protection required under the high cylinder pressures and sustained load cycles of a turbocharged diesel workhorse engine. The lower compression ring (LCR) is a 1.5mm cast iron THM-10 taper-face ring that manages secondary gas sealing and supports the UCR's oil control function. The oil control ring (OCR) is a 2.5mm three-piece stainless steel assembly with chrome-faced rails and a CP-20 expander, delivering consistent radial pressure and precise oil film control throughout the service interval.

Each ring is pre-lapped from the factory, allowing for immediate cylinder wall contact from the first engine start and reducing the duration of the break-in period. The S42246.030 is sold as a single-cylinder set - enough rings for one piston - so the correct quantity must be ordered based on the number of cylinders being rebuilt (the MaxxForce 7 is an 8-cylinder engine). For complete engine rebuilds, 8 sets are required. The companion part numbers in this oversize family include S42246 (STD), S42246.010, S42246.020, and S42246.040 for alternate bore sizes. MAHLE is one of the world's largest original equipment piston ring manufacturers, and the S42246.030 is built to the same standards as the rings MAHLE supplies directly to engine OEMs.