Product Description
Cummins 3802561 — Engine Piston Kit (Standard Bore) for 5.9L 12-Valve
MPN: 3802561 | Also Known As: piston kit, small-bowl piston kit | Typical Contents: piston 3926631, ring set 3802421, retainers 3920691 (kit contents vary by supplier)
Why This Part
- ✓ OE piston geometry for proper compression and combustion on 12-valve 5.9L builds.
- ✓ Standard bore (STD) drop-in when the cylinder measures within spec.
- ✓ Complete kit with piston, rings, pin/retainers (see box contents).
- ✓ Built to Cummins standards for durability and long service life.
Quick Specs
| Type | Engine piston kit (standard bore) |
|---|---|
| OE Part # | 3802561 |
| Cylinder Count | Sold per cylinder (order 6 for a full engine) |
| Application Notes | “Small-bowl” 12-valve piston style—verify by ESN/bowl style before ordering |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1994–1998 | 5.9L 12-Valve 6BT (P7100 “small-bowl”) | Ram 2500/3500 |
Notes: Earlier 1991.5–1993 VE-pump engines commonly use a different “large-bowl” piston. Always verify bowl style and ESN before ordering.
Industrial/Off-Highway: 4B3.9 / 6B5.9 B-Series (verify by ESN and CPL; emissions tier may change piston spec).
Often Paired With
- Full gasket set and head gasket (12-valve)
- Rod & main bearings (size to crank)
- Piston cooling nozzles (inspect/replace as needed)
- Ring compressor & assembly lube
What’s In The Box
- (1) Piston (typ. 3926631)
- (1) Piston ring set (typ. 3802421)
- (2) Retaining rings (typ. 3920691) and wrist pin
Kit contents shown are typical for 3802561; verify contents by supplier.
Install Tips
- Measure cylinder taper/out-of-round; hone or machine as required. Use STD only if bores are in spec.
- Check piston protrusion & ring end gaps; follow Cummins service specs.
- Match bowl style to injector spray pattern; incorrect bowls can affect performance and EGT.
FAQ
WILL THIS FIT MY 1994–1998 5.9L 12-VALVE RAM?Yes—this kit targets the small-bowl 12-valve 5.9L (1994–1998). Always confirm by ESN and bowl style.
DO I ORDER ONE KIT OR A SET OF SIX?Kits are sold per cylinder. Order 6 for a complete engine.
WHAT’S INCLUDED IN THE KIT?Typically piston, ring set, wrist pin, and retainers. See “What’s In The Box” for typical numbers; contents can vary.
WILL THIS WORK ON 1991.5–1993 ENGINES?Those VE-pump engines commonly use large-bowl pistons. Verify ESN/CPL and bowl style before ordering.
IS THIS A GENUINE CUMMINS PART?Yes—3802561 is a genuine Cummins piston kit built to OE specs.
