Product Description
Cummins 3802134 — Marine Style Piston Kit (.040 Over / 1.00 mm)
MPN: 3802134 | Also Known As: .040 over piston kit, 1.00 mm oversize | Application: 5.9L 12-Valve B-Series (Marine bowl upgrade)
Why This Part
- ✓ Marine-style large bowl piston commonly used as a performance upgrade on 12-valve builds (not factory-equipped on Dodge pickups).
- ✓ .040" (1.00 mm) oversize to match cylinders after proper machining/honing.
- ✓ OE materials & geometry for durability under high cylinder pressures.
- ✓ Complete kit contents typically include piston, rings, wrist pin, and retainers*.
*Kit contents may vary by supplier; verify BOM for your ESN.
Quick Specs
| Type | Piston Kit (.040" / 1.00 mm oversize) |
|---|---|
| OE Part # | 3802134 |
| Piston Style | Marine-style large bowl (upgrade) |
| Qty Required | 6 per engine (sold individually per cylinder) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1989–1998 | 5.9L 12-Valve B-Series (Marine bowl upgrade) | Ram 2500/3500 |
Notes: Common upgrade path on 12-valve builds; not factory-equipped on Dodge pickups. Always verify by VIN/ESN and coordinate machine shop work for 1.00 mm oversize.
Often Paired With
- Head gasket set & fasteners for top-end reassembly
- Rod & main bearings (size to crank)
- Ring compressor and plastigage for assembly checks
- Machine shop hone/bore to 1.00 mm over
What’s In The Box
- (1) Cummins Marine-Style Piston (.040" / 1.00 mm OS)
- (1) Matched ring set
- (1) Wrist pin & (2) pin retainers
Install Tips
- Confirm piston-to-wall clearance and ring end-gaps per spec after machining.
- Verify piston protrusion and bowl orientation; check valve reliefs and squish clearance.
- Replace torque-to-yield fasteners where specified; torque/angle per Cummins procedures.
FAQ
WILL THIS FIT MY 1989–1998 5.9L 12-VALVE?Yes—this kit targets 12-valve 5.9L B-Series builds in that range. It’s a marine-style upgrade and was not factory-equipped on Dodge pickups.
WHAT DOES “.040 OVER / 1.00 MM” MEAN?The piston diameter is 1.00 mm larger than standard to match cylinders bored/honed to that oversize. Machine work is required.
WHAT’S INCLUDED IN THE KIT?Typically piston, ring set, wrist pin, and retainers; verify exact BOM for your ESN/order.
IS THIS A FACTORY PISTON FOR DODGE PICKUPS?No—this is the “marine bowl” style commonly used as a performance upgrade on 12-valve builds.
HOW MANY DO I NEED?Six (6) pistons per engine for a full set. This item is sold individually per cylinder.
