Product Description
MAHLE 224-3523WR.040 marine-bowl piston kit with rings is the proven .040" overbore upgrade for the 1989–1998 Cummins 5.9L 12-valve (6BT). Built to OE standards with ~40 mm floating pins and a factory-matched ring pack, this set delivers stable sealing, clean mixture targeting from the marine/QSB-style bowl, and durability under heavy tow or performance fueling.
Why it wins: controlled expansion, consistent ring loading, and bowl geometry that keeps heat where it belongs for reliable power and longevity.
Fitment
- 1989–1998 Dodge/Ram W/D/2500/3500 with 5.9L Cummins 12-valve (6BT)
- Bore size: .040" over (requires cylinders machined to .040" oversize)
- Configuration: Marine/QSB-style bowl (verify head/bowl compatibility on earlier years)
- Includes: Set of six (6) pistons with rings, wrist pins, and clips (as supplied by MAHLE)
Cross-Reference / Alternatives (MAHLE on CPP Diesel)
- Standard bore: MAHLE 224-3523WR (STD)
- +.020 over: MAHLE 224-3523WR.020
- Standard-bowl family (STD): MAHLE 224-3520WR (STD)
- Standard-bowl family (+.040): MAHLE 224-3520WR.040
Specifications for Mahle 224-3523WR.040
| Attribute | Value | 
|---|---|
| Brand | MAHLE | 
| Part Number | 224-3523WR.040 | 
| UPC | 027067913586 | 
| GTIN | 00027067913586 | 
| Engine | Cummins 5.9L 12-valve (6BT) | 
| Bore Size | .040" over | 
| Pin Diameter | ~40 mm (floating) | 
| Ring Pack | Top 3.00 mm • Second 2.40 mm • Oil 4.00 mm | 
| Includes | (6) Pistons, rings, pins & clips (as supplied by MAHLE) | 
| Shipping | Free Shipping (ground) | 
| Prop 65 | This product can expose you to chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. Learn more. | 
FAQ
Is this priced per piston or for a full set?
CPP Diesel sells this as a complete set of six (6) pistons with rings.
 Will this fit my 5.9L Cummins?
Yes, when your engine is machined to .040" over and uses the marine-bowl configuration. Always verify bore, bowl, and pin specs before assembly.
 What’s the difference vs. 224-3523WR (STD) or 224-3523WR.020?
All three share the marine bowl; the only difference is bore size: STD, +.020", or +.040". Choose based on your machine shop’s final bore size.
 Do the rings come pre-installed?
Rings are included and must be gapped and installed per MAHLE/Cummins specifications.
 
 
             
             
             
             
             
             
             
           
           
           
           
           
           
       
                     
             
                   
           
                   
           
           
           
                   
          