MD050390 Piston Ring Set 91.1mm STD for Mitsubishi 4D56 4D55 Engine L200 Pajero Delica

Product Details

Product Overview

This premium MD050390 piston ring set is a direct replacement for Mitsubishi 4D56 and 4D55 diesel engines, commonly found in the L200, Pajero, and Delica models. Manufactured to OE specifications with a standard bore size of 91.1mm, this set ensures optimal compression, oil control, and engine performance. We serve a global B2B clientele, with major markets in North America, Europe, Southeast Asia, the Middle East, and Australia, providing reliable shipping to industrial hubs and ports worldwide.

Key Features & Benefits

• Precision Engineering: CNC-machined rings guarantee a perfect seal within the cylinder, maximizing compression and power output.
• Durable Material: Constructed from high-grade alloyed cast iron with a wear-resistant chrome or molybdenum coating for extended service life.
• Optimized Oil Control: Advanced oil ring design minimizes oil consumption while ensuring proper cylinder wall lubrication.
• Direct Fitment: Standard size (91.1mm) eliminates the need for cylinder honing or oversizing, reducing installation time.
• OEM Quality: Manufactured under strict ISO quality standards, meeting or exceeding original Mitsubishi specifications.

Technical Specifications

OEM Cross-Reference

This piston ring set is a direct replacement for the following Mitsubishi OEM part numbers:

• MD050390 (Main OEM Number)
• MD050391
• MD050392
• ME201629

Note: This part is also compatible with various aftermarket brands that cross-reference to MD050390 for the 4D56/4D55 engine family.

Compatibility

This piston ring set is designed for the following Mitsubishi engine and vehicle applications:

• Engine Models: 4D56 (2.5L Turbo Diesel), 4D55 (2.3L Turbo Diesel)
• Vehicle Applications:
• Mitsubishi L200 / Strada (1986-2007)
• Mitsubishi Pajero / Montero (1982-2006)
• Mitsubishi Delica (L300, L400 series)
• Mitsubishi Starion (4D55)

Important: Always verify engine block bore condition before installation. This is a standard size set; if the cylinder is worn, consider an oversized set.

Global Supply & Distribution

We offer efficient global logistics for B2B orders, ensuring timely delivery to major markets:

• North America: Fast shipping to ports like Los Angeles, Houston, and New York.
• Europe: Direct delivery to Rotterdam, Hamburg, and Antwerp.
• Asia-Pacific: Rapid dispatch to Singapore, Dubai, and Brisbane.
• Middle East & Africa: Reliable service to Jebel Ali, Jeddah, and Durban.

We support bulk orders, drop-shipping, and OEM/private labeling. All packages are professionally packed for export to prevent damage during transit.

Quality Assurance

• Certifications: ISO 9001:2015 certified manufacturing facility.
• Testing: Each ring set undergoes dimensional, hardness, and tension testing before packing.
• Warranty: 12-month warranty against manufacturing defects under normal operating conditions.
• Traceability: All parts are batch-numbered for full traceability from raw material to final product.

FAQ

Q: Can this ring set be installed without honing the cylinder?
A: Yes, this is a standard size (91.1mm) set designed for cylinders that are within factory wear limits. However, we strongly recommend checking the cylinder bore for taper and out-of-roundness. If the bore is glazed or slightly worn, a light deglazing with a ball hone will improve ring seating and oil control.

Q: What is the correct installation procedure for these rings?
A: Install compression rings with the “TOP” marking facing upward. Stagger ring gaps 120 degrees apart around the piston (do not align gaps with the wrist pin). Ensure the oil ring expander ends do not overlap. Always lubricate rings and cylinder walls with clean engine oil before installation.

Q: How do I identify if my 4D56 engine needs a standard or oversized piston ring set?
A: Measure the cylinder bore diameter with a bore gauge at three points (top, middle, bottom). If the bore measures between 91.100mm and 91.130mm, standard rings are suitable. If the bore exceeds 91.150mm, you will likely need an oversized set (0.25mm, 0.50mm, etc.). Worn cylinders will cause poor compression and excessive oil consumption.