Part number 6506-61-4370 refers to the OEM-style cast iron turbine housing for Komatsu turbochargers, a critical high-temperature pressure-bearing component tailored for SA6D125 series engines fitted on Komatsu PC400-5/6 excavators and WA470 wheel loaders. As an essential core part of engine turbocharging systems in construction machinery, it is categorized as high-consumption precision casting across the global aftermarket engineering spare parts industry.
In terms of material and manufacturing technology, this turbine housing is integrally cast from heat-resistant ductile iron blended with chromium and molybdenum alloy elements, a premium material far superior to ordinary grey cast iron. The alloy formulation enables continuous stable operation under exhaust temperature ranging from 650℃ to 750℃, featuring outstanding resistance against high-temperature creep and thermal oxidation. The complete production workflow consists of precision sand casting, stress-relief annealing treatment, CNC precision boring and flange face milling. Strict dimensional tolerances are implemented for mounting holes as per original OEM drawings; flatness of end faces and inner bore concentricity directly impact the assembly precision of turbo rotors. The spiral runner inside the housing is produced based on OEM hydrodynamic parameters to guarantee efficient exhaust gas flow guidance.
Functionally, the spiral volute runner inside the casing guides high-temperature exhaust gas discharged from the engine exhaust manifold. The flowing exhaust pushes the turbine wheel to spin at high speed, converting waste exhaust thermal energy into mechanical boost power. Markings including OEM part No.6506-61-4370 and AIR1.75 are permanently cast on the outer surface; "1.75" stands for the housing A/R flow coefficient, a fixed parameter calibrated to match the displacement and boost requirement of SA6D125 engines. Improper replacement with housings of mismatched A/R ratios will trigger insufficient boost pressure, excessive black smoke emission and noticeable engine power loss. Its integrated dual-side mounting lugs and six-bolt flange are standardized for seamless fitting with turbocharger central housings and exhaust pipelines.
For market application and wear characteristics, this component is widely installed on Komatsu PC400 excavators and WA470 loaders working in mines and heavy earthmoving projects. Alternating thermal expansion & contraction under extreme temperature shifts plus corrosive acid exhaust from inferior fuel are the primary causes of housing cracking and inner cavity erosion, making it a frequently replaced service part in machinery maintenance. Due to the high cost of genuine OEM original housings, high-quality aftermarket cast alternatives have dominated the global spare parts market. Qualified replacement products must pass air tightness pressure tests and high-temperature fatigue verification to meet international construction component standards.
In international spare parts trading, 6506-61-4370 ranks among top-selling aftermarket items for export. Large quantities of Komatsu machines are operating across Southeast Asia and Africa, resulting in persistent stable market demand. With OEM-equivalent dimensional accuracy and cost-effective pricing, our qualified turbine housing has become the preferred purchasing option for global machinery repair workshops and spare parts wholesalers.
