- ADDRESS：Wanda Plaza, Jinan, Shandong, China
- Wanda Plaza, Jinan, Shandong, China
- +8617615809553
- info@deruna.com
The WEICHAI WP12 Piston Assembly is a complete piston unit designed for WP12 diesel engines with 126mm bore and 155mm stroke, delivering 11.596L displacement across six cylinders. The piston is manufactured from high-strength aluminum-silicon alloy, featuring anodized ring grooves that resist micro-welding and groove wear under high-temperature operation. This assembly includes the piston body, three precision-ground piston rings, a floating piston pin, and two spiral retaining rings, all pre-assembled and ready for installation.
The WEICHAI WP12 Piston Assembly features a reinforced skirt design with anti-friction coating that reduces scuffing risk during cold starts and minimizes cylinder liner wear. The piston compression height is precisely set at 72.5mm for standard engines and 71.8mm for low-compression variants used in high-boost applications. Three piston rings are included: a chromium-ceramic coated top compression ring, a second tapered ring, and a three-piece oil control ring with expander spring that maintains optimal oil film thickness.
The floating piston pin in the WEICHAI WP12 Piston Assembly is carburized and precision-ground to a mirror finish, riding on a bronze bushing pressed into the connecting rod small end. This design allows the pin to rotate freely, distributing wear evenly and extending service life. The pin is secured by two spiral retaining rings made from spring steel, which prevent axial movement while allowing thermal expansion. Each assembly is weight-matched within 5 grams across a set of six cylinders to minimize engine imbalance.
Applications for the WEICHAI WP12 Piston Assembly include Shacman F3000/X3000, Sinotruk HOWO A7, Dongfeng KL, SDLG wheel loaders, XCMG excavators, and marine propulsion systems using the WP12 engine platform. This assembly is compatible with Euro III, IV, and V emission variants. When ordering, specify standard compression height (72.5mm) or low-compression version (71.8mm). Every assembly comes with a one-year warranty against material defects.
| NO. | Part NO. | Description |
|---|---|---|
| 1 | 612630020314 | Complete Piston Assembly (Std, 72.5mm height) |
| 2 | 612630020152 | Piston Body (Al-Si alloy, anodized grooves) |
| 3 | 612630020021 | Piston Pin Clamping Ring (spiral, spring steel) |
| 4 | 1003087521 | Piston Ring Set (3 rings, chrome-ceramic top) |
| 5 | 612600030072 | Piston (Oversize 0.25mm, for rebored cylinders) |
| 6 | 612600030080 | Piston (Oversize 0.50mm, for rebored cylinders) |
| 7 | 612630020009 | Piston Pin (floating type, carburized steel) |
| 8 | 612630900001A | Cylinder Liner & Piston Kit (6 cylinders, Euro III) |
Our WEICHAI WP12 Piston Assembly is sourced directly from IATF 16949 certified manufacturers who supply the genuine Weichai Power aftermarket network. Each piston undergoes dimensional inspection on three-coordinate measuring machines, hardness testing to verify 28-32 HRC surface treatment, and thermal cycling validation. We reject any piston with porosity, ring groove damage, or dimensional deviation beyond ±0.02mm on skirt diameter. This quality control ensures every assembly fits perfectly without additional machining.
The WEICHAI WP12 Piston Assembly we supply features superior metallurgy compared to generic aftermarket copies. While counterfeit pistons use lower-grade aluminum alloys, our pistons use certified high-silicon aluminum alloy (Si 12-14%) with documented material certificates. The anodized ring grooves are 40% harder than standard anodizing, resisting micro-welding from ring flutter. Independent testing confirms our assembly withstands 2000 hours of continuous high-load operation without measurable skirt wear or ring groove deformation.
We maintain extensive inventory of the WEICHAI WP12 Piston Assembly across multiple regional warehouses, with over 2,500 complete assemblies ready for immediate dispatch. For engine rebuilders, we offer complete six-cylinder sets pre-weight-matched to within 3 grams (exceeding factory spec of 5 grams). Each set comes with a full ring set, piston pins, retaining rings, and a certificate of conformance. Bulk orders receive volume discounts and extended warranty up to 18 months.
Real-world data: a fleet of 30 dump trucks in Australian mines achieved over 18,000 hours before piston replacement—40% longer than industry average. Another customer reported 30% lower oil consumption and 5% better fuel economy. The optimized combustion bowl geometry in our WEICHAI WP12 Piston Assembly reduces soot emissions by 15% compared to aftermarket alternatives. Choose our assembly for lower total cost of ownership and reduced downtime.
Regular oil analysis is the most effective preventive maintenance for the WEICHAI WP12 Piston Assembly. Monitor wear metals—elevated aluminum (above 80 ppm) indicates piston scuffing or ring groove wear, while iron above 150 ppm signals cylinder liner wear. Perform oil sampling every 400 hours under severe duty or 600 hours for highway operation. A sudden aluminum spike often precedes piston failure by 50-100 hours. Always use API CK-4 or CJ-4 diesel oil with TBN at least 10.
When installing a new WEICHAI WP12 Piston Assembly, follow the break-in procedure. Limit engine load to 75% of rated power for the first 60 hours to allow rings to seat. Avoid extended idling to prevent ring glazing. After break-in, change oil and filter. Orient ring gaps at 120° intervals with top ring gap away from thrust side. The marked side of rings must face the piston top, and each ring’s opening angle should be set at 60° per the manual.
Monitor the WEICHAI WP12 Piston Assembly for signs of wear. Perform crankcase blow-by measurement every 500 hours; blow-by exceeding 100 L/min suggests worn rings. Oil consumption above 0.2% of fuel consumption indicates ring sticking. Listen for a light tapping noise that increases with speed—this can indicate excessive piston-to-wall clearance. Perform compression and leak-down tests if any signs appear. Use a borescope to inspect pistons without head removal.
For long-term storage, rotate the engine manually every 30 days to prevent rings from sticking. Before start-up after three months of storage, pour oil into each cylinder and crank with starter (fuel off) to pre-lubricate. During overhauls, measure piston skirt diameter at 90° to pin axis. Replace the WEICHAI WP12 Piston Assembly if any thermal damage is found. Inspect piston cooling jets for clogging; blocked jets cause piston overheating within 100 hours. Replace oil filters with genuine Weichai parts at every oil change.
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