Product Description
Cummins 3802564 — Engine Piston Kit (.020 / 0.50 mm), Small-Bowl
MPN: 3802564 | Also Known As: piston kit (.020 OS), small-bowl stock piston | Includes: piston, rings, wrist pin, clips
Why This Part
- ✓ OE “small-bowl” design for stock 12-valve performance and durability.
- ✓ .020 in (0.50 mm) oversize—ideal after a standard cleanup bore/hone.
- ✓ Complete kit (piston, rings, pin, clips) for one cylinder.
- ✓ Built to Cummins specs for proper geometry, weight, and clearances.
Quick Specs
| Type | Engine piston kit (.020 in / 0.50 mm oversize) |
|---|---|
| OE Part # | 3802564 |
| Style | Small-bowl (stock bowl), 12-valve |
| Qty Required | 6 kits per engine (sold individually) |
Verified Fitment (Automotive)
| Year Range | Engine | Chassis |
|---|---|---|
| 1994–1998 | 5.9L 12-Valve 6BT (P-pump), “small-bowl” piston | Ram 2500/3500 |
Compatibility Notes: Commonly listed for 1991.5–1998 12-valve applications as well; confirm by ESN, piston mark, and bowl style if working on 1991.5–1993 trucks.
Often Paired With
- Lower Engine Gasket Set: Cummins 3802376 (’89–’98 5.9L)
- Piston Ring Set (.020): Cummins 3802422 (if rings needed separately)
- Head Gasket / Head Bolts: As required for overhaul
- Machine Work: Bore/hone with proper plateau finish; verify clearances
What’s In The Box
- (1) Genuine Cummins Piston Kit 3802564 (.020 OS): piston, ring pack, wrist pin, retaining clips
Install Tips
- Measure cylinder, bore/hone to specification for .020 in (0.50 mm) oversize.
- Check ring end-gaps; orient rings per Cummins service manual.
- Observe piston orientation (mark toward front); verify piston-to-wall clearance.
- Cleanliness is critical—thoroughly wash bores after honing.
FAQ
WILL THIS FIT MY 1994–1998 12-VALVE RAM?Yes—this .020 oversize “small-bowl” piston kit is the common OE choice for 1994–1998 5.9L 12-valve builds (verify by ESN/piston code).
WHAT DOES .020" (0.50 MM) OVERSIZE MEAN?The cylinder is bored/honed .020" larger than stock. This kit is sized for that standard oversize.
WHAT’S INCLUDED IN THE KIT?One cylinder’s piston, ring pack, wrist pin, and pin clips. Order six kits for a full engine.
IS THIS THE “SMALL-BOWL” STOCK PISTON?Yes—this matches the OE small-bowl (stock bowl) style used on factory 12-valve applications.
DOES THIS ALSO FIT 1991.5–1993?Many sources list 1991.5–1993 coverage, but bowl style and piston marks vary—confirm by ESN and piston code before ordering.
