Product Description
CUMMINS 3802564 OEM ENGINE PISTON KIT (.020) – RAM 5.9L 12-VALVE (1994–1998)
The genuine CUMMINS 3802564 OEM ENGINE PISTON KIT (.020) is the correct oversize piston assembly required for professional-grade engine rebuilding on the 1994–1998 5.9L Cummins 12-valve platform. Whether you are restoring compression, repairing scoring, or completing a full overhaul, this kit provides the exact factory-grade metallurgy, skirt design, ring package, and pin fitment engineered for long life in B-series engines.
Unlike aftermarket copies, this OEM Cummins piston kit maintains proper thermal expansion characteristics, ring sealing integrity, and combustion stability — all critical for engines running elevated cylinder pressures or towing workloads. When your machine shop finishes your cylinders to a .020" oversize, this is the correct piston set to install for factory-reliable performance and durability.
For full engine refreshes, pair your piston kit with additional genuine Cummins replacement components such as the CUMMINS 3937224 MAIN BEARING SET and other rotating assembly components available in our Cummins catalog.
Key Features
- Genuine Cummins OEM .020" oversize piston for correct machine shop cylinder finishing.
- Complete kit includes piston, rings, piston pin, and retaining clips (as packaged by Cummins).
- Correct alloy composition and skirt geometry for optimal thermal expansion and long service life.
- Engineered for 1994–1998 12-valve B-series engines with VE or P7100 fuel systems.
- Ideal for complete engine rebuilds requiring oversize machining.
Fitment Details
- Engine: 5.9L Cummins B-Series 12-Valve (6B / 6BT)
- Years: 1994–1998 Ram 2500 / 3500 (verify by ESN)
- Fuel Systems: VE pump (1994 early), P7100 pump (1994.5–1998)
- Bore Size: .020" oversize (machine shop required)
Always verify compatibility using your engine serial number (ESN) before ordering internal engine components.
Cross-Reference & Companion Cummins Parts
Pair this piston kit with other genuine Cummins rebuild components:
Common Cummins internal references: 3802564, 3802564-020, 3802564RX, 3802564-CPL (verify by ESN for accuracy).
Installation Notes
- Cylinders MUST be bored and honed to .020" oversize to use this piston.
- Machine shops should measure piston-to-wall clearance according to Cummins service specifications.
- Always check ring gap and orientation before installation.
- Lubricate pin and piston bores before assembly.
Specifications for cummins 3802564
| Attribute | Value |
|---|---|
| Brand | Cummins (Genuine OEM) |
| Cummins Part Number | 3802564 |
| Oversize | .020" (requires machining) |
| Engine Compatibility | 5.9L Cummins 12-Valve (1994–1998 Ram 2500/3500) |
| Included Components | Piston, rings, piston pin, retaining clips (as packaged by Cummins) |
| UPC | 700358207569 |
| GTIN | 700358207569 |
| Shipping Weight | Approx. 2.5–3.5 lbs per piston kit |
| Typical Shipping Method | Standard ground; ships quickly from CPP Diesel |
| Cross Reference | 3802564-020, 3802564RX, 3802564-CPL sets (verify by ESN) |
| E-Codes | Used on multiple 6B/6BT emissions families; verify by CPL/ESN |
| Prop 65 Warning | WARNING: Cancer and reproductive harm – www.P65Warnings.ca.gov |
| Country of Origin | As labeled by Cummins (varies by batch) |
Frequently Asked Questions
IS THIS A COMPLETE PISTON KIT?
Yes. This is a genuine Cummins piston kit including the piston, pin, rings, and retainers exactly as packaged by Cummins.
DO I NEED TO MACHINE THE BLOCK TO USE THIS .020" PISTON?
Yes. A machine shop must bore and hone your cylinders to .020" oversize for proper clearance and ring seal.
WILL THIS FIT ALL 5.9L 12-VALVE ENGINES?
This piston fits many 1994–1998 Ram 5.9L 12-valve applications, but you must verify via ESN for proper compatibility.
CAN I MIX STANDARD AND OVERSIZE PISTONS?
No. All cylinders must match their designated bore size. Never mix standard and oversize pistons within one engine.
IS THIS PART BETTER THAN AFTERMARKET PISTONS?
Yes. Genuine Cummins pistons use the correct alloy, skirt design, and ring pack specifications for long life and OEM performance.
