Product Description
MAHLE 197952335 MS Cast Aluminum Piston Set is engineered for the 1989–1998 Cummins 5.9L 12-valve (6BT). This kit uses MAHLE’s cast-performance diesel piston design with coated skirts and includes a full ring pack. Sized for a 4.035" bore (+.020" over) with 4.724" stroke, 7.559" rod, 1.575" pin, and approximately -54.1cc bowl volume targeting ~14.9:1 compression (typical CR calc assumes ~0.019" protrusion and 0.060" x 4.150" gasket). Ring set S42170 is included with many MAHLE cast diesel kits or available separately in oversizes.
- Material: Cast aluminum (diesel cast-performance)
- Piston style: Dish (early 12V & marine-style bowl), short-pin design
- Skirt: Grafal-type anti-friction coating
- Includes: 6 pistons, 6 pins, locks, and ring sets (verify contents by batch)
Fitment
- 1989–1993 Dodge D/W 250 & 350 with 5.9L Cummins 12V (6BT)
- 1994–1998 Dodge Ram 2500 & 3500 with 5.9L Cummins 12V (P-pump)
- Note: 4.035" denotes +.020" overbore. Confirm machine work and clearances per MAHLE recommendations.
Cross Reference Numbers
- Summit Racing: MLE-197952335 (Mahle Cast Aluminum Diesel Piston & Ring Kit)
- JEGS: 644-197952335T (variant listing)
- Ring Set: MAHLE S42170 (standard & oversizes like S42170-020)
What’s Included
Six (6) pistons with pins & locks; ring sets for six cylinders (verify specific contents on your kit).
FAQ
Will these fit my 1989–1998 12-valve Cummins?
Yes—these are built for the 5.9L 12V 6BT. Ensure your block is machined to 4.035" (+.020").
What ring set do I need?
MAHLE S42170 is the correct ring family; use S42170-020 for +.020" (4.035") applications.
What compression ratio will I see?
Around 14.9:1 is typical for this bowl volume when using common Cummins build assumptions; always measure protrusion/deck and gasket to calculate your actual CR.
Are these forged?
No—this is a cast-performance diesel piston set designed for durability in street/work builds. For competition-only builds, consider MAHLE forged options.
