Compatible Models: NY160, N165, N180, EY180, N210, EY220, N260, EY260, N280A, N330, S165, S185, M200L, M220L, RAL170, MAL220, UAL200UT, T240, T260, Z280DT, Z280ET, MF290I. Product OverviewDONGFANG cylinder heads are high-quality aftermarket replacement parts independently developed and manufactured by DONGFANG. They are compatible with Yanmar series marine diesel engines and industrial diesel power equipment, and are widely used for routine maintenance and failure replacement of offshore fishing vessels, workboats, small commercial vessels, and diesel generator sets.The cylinder head is a core pressure-bearing and sealing component of a diesel engine, continuously exposed to high combustion pressure, high-temperature thermal cycles, and continuous mechanical vibration during operation. Its structural strength, heat dissipation performance, machining accuracy, and sealing stability directly affect engine power output, fuel economy, and overall service life.Yanmar power equipment is widely used in small and medium-sized vessels and industrial power fields due to its advantages of compact structure, stable operation, low fuel consumption, and convenient maintenance. It has consistent and strict requirements for spare parts in terms of thermal fatigue resistance, corrosion resistance, and installation compatibility.Based on independent dimensional adaptation development and process optimization, DONGFANG adopts precision casting, heat treatment stabilization, and CNC precision machining processes, combined with complete factory inspection, to provide global marine maintenance companies, spare parts distributors, and end users with standardized replacement solutions featuring high compatibility, high stability, and high cost performance.II. Compatible Models and Application ScenariosDONGFANG compatible cylinder heads can accurately match mainstream Yanmar marine and industrial diesel engine series.Core Compatible Models:NY160, N165, N180, EY180, N210, EY220, N260, EY260, N280A, N330, S165, S185, M200L, M220L, RAL170, MAL220, UAL200UT, T240, T260, Z280DT, Z280ET, MF290Application Scenarios:•Main propulsion systems of offshore fishing vessels, workboats, inland waterway vessels, and small commercial vessels•Marine auxiliary generator sets and backup power systems•Industrial stationary diesel power generation and construction machinery power equipmentThe product can be accurately matched one-to-one according to customer engine models, part numbers, old parts, or drawings, achieving direct replacement without modification.III. Core Product Functions1. Stable Combustion Chamber Sealing to Maintain Constant Power OutputThe high-precision sealing structure reliably withstands high combustion pressure, preventing gas leakage and cylinder pressure loss. It ensures stable compression ratio and smooth power output, effectively improving the fuel consumption performance of Yanmar engines.2. Optimized Intake and Exhaust Circulation to Improve Combustion EfficiencyThe air passage structure is scientifically optimized to ensure sufficient air intake and smooth exhaust discharge. It improves combustion efficiency, effectively reduces daily operating energy consumption, and meets the requirements of fishing vessels operating continuously at sea for long periods.3. Precise Fuel Injection Positioning for More Stable Combustion ConditionsThe injector mounting position is precision-machined as an integrated structure, providing reliable sealing and accurate positioning. It ensures uniform fuel atomization and prevents common failures such as leakage, carbon buildup, difficult starting, and black smoke emissions.4. Efficient Circulating Heat Dissipation with High Temperature and Corrosion ResistanceThe specially optimized cooling water passages provide fast and balanced heat dissipation, effectively removing high temperatures from the combustion chamber and valve areas. The material resistance is optimized for marine high salt spray and high humidity environments, significantly reducing the risk of thermal cracks, cylinder head deformation, and water passage corrosion.IV. Dual Material Selection for Different Operating Conditions (Full Coverage)1. High-Strength Alloy Gray Cast Iron (General Best-Selling Model)It features a stable structure, balanced heat resistance, high machining accuracy, and excellent cost performance. It is suitable for routine maintenance and replacement of most offshore fishing vessels, small cargo ships, marine auxiliary engines, and industrial generator sets.2. Compacted Graphite Iron CGI (Heavy-Duty Durable Model)It provides comprehensive improvements in strength, toughness, thermal crack resistance, and thermal fatigue resistance. It is suitable for harsh operating conditions including long-term full-load operation, frequent starts and stops, and extended offshore operation, providing longer service life and extremely low repair frequency.V. Precision Manufacturing Process•Resin sand precision casting ensures well-formed internal water passages, air passages, and combustion chambers with low defect rates and good consistency.•Artificial aging heat treatment releases casting internal stress, preventing deformation and dimensional shifting during long-term high-temperature operation.•Full CNC precision machining is applied to the fire deck surface, valve holes, injector holes, and mounting holes, ensuring accurate and controllable tolerances.•Each finished product independently undergoes dimensional inspection, high-pressure water pressure testing, air-tightness testing, and professional anti-rust and anti-corrosion treatment.Highly suitable for harsh working environments including coastal high humidity, high salt spray, and dusty conditions.VI. Improvement of Common FailuresIt can effectively improve problems such as fire deck thermal cracks, cooling water passage corrosion and leakage, cylinder head surface warping and gasket failure, valve seat sealing leakage, injector hole leakage, power reduction, increased fuel consumption, and black exhaust smoke, significantly enhancing equipment operating stability.VII. Core Advantages of DONGFANG Products1. High Compatibility Direct Installation with No Modification RequiredManufactured strictly according to equipment assembly standards, with mounting holes, water passages, and air passages fully matched. No grinding or modification is required, greatly shortening vessel downtime for maintenance.2. Targeted Optimization for Marine Operating ConditionsSpecifically designed for Yanmar offshore fishing vessels, long-term low-speed continuous operation, and high-salt corrosion environments. The thermal resistance, sealing performance, and corrosion resistance are enhanced, providing better durability than ordinary replacement parts.3. Full Inspection Before Delivery, Stable and Controllable QualityAll products undergo casting inspection, dimensional verification, water pressure testing, and air-tightness testing to prevent quality issues such as water leakage, gas leakage, and assembly deviation.4. Flexible Supply + Private Label Customization ServiceSupports sample trial orders, small-batch replenishment, and large-volume stock exports. Private brand customization services are available to meet the diverse procurement needs of global trade, maintenance companies, and distributors.VIII. Product Application FieldsWidely compatible with maintenance and replacement of main engines for various offshore fishing vessels, workboats, inland waterway vessels, and small commercial vessels;Suitable for routine maintenance of marine auxiliary engines, marine generator sets, and backup power systems;Also covers supporting applications for industrial diesel power generation, construction machinery, and small power equipment maintenance. Compliance DisclaimerThe Yanmar brand and model numbers mentioned on this page are only used to describe the equipment compatibility range of DONGFANG products and are provided solely as a reference for customer selection.All DONGFANG cylinder heads are third-party aftermarket replacement parts independently designed, manufactured, and inspected by DONGFANG, and are not original equipment manufacturer (OEM) parts.DONGFANG has no authorization, cooperation, affiliation, or OEM manufacturing relationship with the Yanmar brand. All trademarks belong to their respective owners and are only used for compatibility identification purposes.

Compatible Models: DL-20、DL-22、DL-26、DL-28、DL-32、5DK-20、6DK-20、DK-28、DS-26、PS-26H (D)、DC-17、DE-18 I. Product OverviewDONGFANG cylinder heads are third-party replacement spare parts independently developed and manufactured by DONGFANG, suitable for maintenance applications of Daihatsu marine diesel engines and industrial diesel power systems.The cylinder head is a core structural component of the diesel engine combustion chamber. It is installed on the upper part of the cylinder block and works together with the piston and cylinder liner to form a sealed combustion space. During long-term operation, the cylinder head continuously withstands high-temperature and high-pressure combustion, cyclic thermal loads, and mechanical vibration. The structural strength, sealing capability, and machining accuracy of the component directly determine the operating efficiency and service life of the entire power equipment.Daihatsu Diesel series engines are widely used in marine propulsion units, marine auxiliary engines, and diesel generator sets due to their stable operation and excellent durability, making them suitable for long-term continuous operation. Marine and industrial power equipment often operate under high loads for extended periods in complex environments, which places high requirements on the thermal fatigue resistance and structural stability of replacement cylinder heads.DONGFANG cylinder heads are developed through measurement and mapping based on the original structures of corresponding engine models, mold development, and are manufactured using precision casting, heat treatment, and CNC precision machining processes. The product’s assembly dimensions, sealing performance, and operating stability meet the maintenance and replacement requirements of power equipment, providing reliable maintenance spare part solutions for shipbuilding and repair companies, diesel engine parts distributors, and industrial power equipment users. II. Applicable Engine ModelsDONGFANG cylinder heads can match multiple Daihatsu diesel engine models and serve maintenance applications for marine power systems, marine auxiliary engines, and industrial diesel engines.Applicable model list:DL-20, DL-22, DL-26, DL-28, DL-32, 5DK-20, 6DK-20, DK-28, DS-26, PS-26H (D), DC-17, DE-18Applicable equipment categories:•Marine main propulsion diesel engine units•Marine auxiliary power generation systems•Stationary industrial diesel power equipmentDifferent engine models have differences in combustion chamber structures, valve arrangements, fuel injection systems, and cooling water passage designs. During product development, DONGFANG optimizes the products according to the structural differences of each model to ensure accurate assembly dimensions, precise valve installation positions, qualified injector hole machining, and stable combustion chamber sealing.Customers can provide the engine model, original part number, or physical photos, and DONGFANG will assist in verifying the matching solution. III. Main Functions of Cylinder Head1. Withstand Combustion Pressure and Maintain Stable Power OutputThe cylinder head withstands the high-temperature and high-pressure gases generated by fuel combustion and forms an effective seal with the cylinder liner. It maintains stable working pressure inside the combustion chamber, prevents gas leakage, improves compression efficiency, and ensures continuous power output of the engine unit. For diesel units requiring uninterrupted operation, reliable sealing is a fundamental condition for stable operation.2. Control Intake and Exhaust Circulation to Improve Combustion EfficiencyThe cylinder head integrates intake passages, exhaust passages, valve seats, and valve guides. Optimized air passage structures improve gas exchange efficiency, promote complete fuel combustion, and reduce energy loss.3. Support Fuel Injection ComponentsThe injector mounting base is precision-machined to firmly support fuel injection components, ensuring accurate injector positioning and stable injection conditions. It enables uniform combustion and reduces abnormal component wear.4. Dissipate Combustion Heat and Reduce Thermal Load DamageMarine diesel engines generally operate continuously for long periods, and heat dissipation performance directly affects the service life of the entire engine. The cooling water chamber inside the cylinder head continuously removes heat from the combustion area, reduces thermal stress around the combustion chamber, valve area, and injector, and minimizes problems such as thermal cracks, valve seat damage, and cylinder head deformation caused by long-term high-temperature operation. IV. Optional Material SolutionsBased on different engine models, operating loads, and application environments, DONGFANG provides two mature material options:1. High-Strength Alloy Gray Cast IronIt features stable casting performance, good machinability, qualified thermal fatigue resistance, and outstanding cost performance.Applicable scenarios:Marine auxiliary engines, small and medium-sized marine power units, and conventional diesel generator sets.2. Compacted Graphite Iron (CGI)It provides higher mechanical strength, better thermal crack resistance, and improved fatigue durability.Applicable scenarios:Marine main engines operating continuously for long periods and high-load industrial diesel power equipment. V. Manufacturing Process1. Resin Sand Precision CastingComplex internal structures such as cooling water passages, intake and exhaust passages, and combustion chambers are formed as an integrated structure, reducing casting defects such as pores and shrinkage cavities.2. Artificial Aging Heat TreatmentIt eliminates internal stresses generated during casting, improves dimensional stability under long-term high-temperature operating conditions, and reduces the possibility of thermal deformation.3. CNC Precision MachiningThe fire deck surface, valve mounting holes, injector holes, and mounting bolt holes are precision-machined. Critical dimensions are matched according to engine assembly requirements.4. Surface Anti-Corrosion Treatment and Full Process InspectionProducts receive anti-rust surface treatment. Each unit undergoes dimensional inspection, water pressure resistance testing, and air-tightness testing in sequence, allowing adaptation to high-humidity and high-salt corrosion marine environments and ensuring long-term reliable sealing performance. VI. Common Failure Reference1. Thermal Cracks on Combustion SurfaceLong-term high-load operation, poor cooling system conditions, and concentrated cyclic thermal stress may cause thermal cracks, which can lead to power reduction, insufficient compression pressure, and abnormal coolant consumption.2. Valve Seat Wear and BurningContinuous exposure of valves to high-temperature impact may reduce sealing performance, lower combustion efficiency, and cause engine unit vibration.3. Cooling Water Chamber CorrosionMarine salt content and coolant quality issues may cause water passage corrosion, leakage, and reduced heat dissipation capability.4. Injector Position Sealing FailureLong-term alternating pressure changes may result in fuel leakage, increased carbon deposits, and difficult engine starting.VII. Advantages of Choosing DONGFANG Cylinder Heads1. Developed Based on Original Engine Structures to Meet Maintenance Replacement RequirementsProduct dimensions are verified through measurement and mapping, providing good assembly compatibility, reducing on-site adjustment workload, and supporting fast maintenance replacement.2. Optimized Performance for Long-Term Operating ConditionsDesigned according to the continuous operation characteristics of marine power systems, the products are optimized for thermal resistance, fatigue resistance, and long-term sealing stability.3. Complete Standardized Quality Inspection ProcessEach product undergoes casting appearance inspection, precision dimensional inspection, water pressure testing, and air-tightness testing to reduce operation and maintenance risks for end users.4. Flexible Supply MethodsSupports sample production, small-batch orders, and large-volume exports, providing long-term stable supply cooperation for spare parts distributors.5. Customized Development and Private Brand Supporting ServicesCustomized development can be carried out according to customer drawings and samples, supporting requirements such as mold development and private label packaging. VIII. Application Fields1. Marine Power SystemsSuitable for replacement and maintenance of Daihatsu diesel engines installed on commercial ships, fishing vessels, engineering vessels, and inland waterway transport vessels.2. Marine Auxiliary Power EquipmentIncluding marine diesel generator sets, auxiliary diesel engines, and ship emergency standby power systems.3. Industrial Diesel Power EquipmentApplicable to stationary diesel generators, industrial power units, and maintenance markets for various diesel-powered equipment. Compliance DisclaimerThis product is a third-party compatible replacement spare part independently manufactured by DONGFANG and is not an original Daihatsu Diesel product. Our company has no affiliation, authorization, or cooperation relationship with the Daihatsu Diesel brand owner. The trademarks mentioned herein belong to their respective legal rights holders and are only used to indicate the applicable engine models of the product.

Compatible Models: 6KSLH275, 6GSLH275, 6GSLH300, 6ESLH633, 6KSLH370, 6ZSHC370, 6GSLH370I. Product OverviewDONGFANG cylinder heads are third-party compatible replacement spare parts independently manufactured by DONGFANG, suitable for Makita marine and industrial diesel engines, and widely used for maintenance and replacement of marine main engines, auxiliary engines, and generator sets.The cylinder head is a core high-pressure load-bearing component of a diesel engine, continuously exposed to high temperatures, high pressure, and alternating loads during operation. The product’s structural strength, sealing accuracy, and machining quality directly affect the overall operating stability and service life of the engine.DONGFANG adopts precision casting, heat treatment stabilization, and CNC precision machining processes, combined with standardized factory inspection, to provide stable and cost-effective replacement solutions for marine operating conditions.II. Compatibility Range and Application ScenariosCompatible with mainstream Makita marine diesel engine models.Application scenarios:•Marine main propulsion power systems•Marine auxiliary generator sets•Industrial stationary diesel power equipmentThe assembly dimensions can be accurately matched one-to-one based on the engine model, part number, old parts, or drawings provided by customers, achieving non-destructive replacement.III. Core Product Functions1. Stable Combustion Chamber Sealing to Maintain Smooth Power OutputMaintains stable cylinder pressure, prevents pressure loss and gas leakage, and ensures continuous and stable operation of the engine unit.2. Optimized Intake and Exhaust Flow to Reduce Operating Energy ConsumptionThe air passage structure is reasonably designed to ensure sufficient gas exchange, improve combustion efficiency, and reduce power loss.3. Precision Fuel Injection Installation Structure for Stable Combustion ConditionsThe injector holes are precision-machined to ensure reliable positioning and sealing, reducing problems such as fuel leakage and abnormal combustion.4. Efficient Circulating Heat Dissipation to Resist High-Temperature Fatigue DamageThe cooling water passage heat dissipation performance is optimized to effectively reduce common high-temperature failures such as thermal cracks and cylinder head deformation.IV. Dual Material Options for Different Operating Conditions1. High-Strength Alloy Gray Cast IronIt provides stable performance and high cost-effectiveness, suitable for routine maintenance of conventional ships and industrial equipment.2. Compacted Graphite Iron (CGI)It provides higher strength, toughness, and thermal crack resistance, suitable for heavy-duty, high-load, and long-term continuous operating conditions.V. Manufacturing Process•Resin sand precision casting ensures a well-formed internal structure with a low defect rate.•Aging heat treatment eliminates internal stress, preventing deformation during long-term operation.•CNC precision machining is applied to core holes and sealing surfaces, ensuring high assembly accuracy.•Each individual product undergoes dimensional inspection, water pressure testing, air-tightness testing, and anti-corrosion treatment.Suitable for harsh marine working environments with high salt spray and high humidity.VI. Improvement of Common FailuresIt can effectively improve common issues such as thermal cracks, poor valve sealing, cooling water passage corrosion, injector leakage, and cylinder head deformation, enhancing the overall stability of equipment operation.VII. Core Advantages of DONGFANG Products1. High Compatibility Direct Replacement, Shortening Maintenance TimeDimensions match assembly standards accurately, requiring no modification or grinding, reducing equipment downtime losses.2. Special Optimization for Marine Operating ConditionsThe structural durability is optimized for marine environments with high temperatures, high salt content, and high loads.3. Full Inspection Before Delivery, Controllable QualityEach product undergoes multiple pressure tests, air-tightness inspections, and dimensional inspections to prevent potential quality risks.4. Flexible Supply and Customized ServicesSupports sample orders, bulk orders, private labeling, and customized production based on customer drawings and samples.VIII. Application FieldsWidely applicable to maintenance of main engines for fishing vessels, cargo ships, and engineering vessels;Covers marine auxiliary engines, generator sets, and backup power systems;Suitable for maintenance applications of industrial power equipment equipped with Makita diesel engines. Compliance DisclaimerThe Makita brand and model numbers mentioned on this page are only used for product compatibility description and are provided solely as a reference for customer selection.All DONGFANG cylinder heads are third-party aftermarket replacement parts independently designed, manufactured, and inspected by DONGFANG, and are not original equipment manufacturer (OEM) parts.DONGFANG has no authorization, cooperation, or affiliation relationship with Makita, and is not involved in OEM manufacturing or brand co-branding.All trademarks belong to their respective brand owners and are used only for compatibility matching purposes.

Compatible Models: L16/24, L23/30, L23/30H, L28/32A, S26MC, L31, L35MC, S35MC, L50MC-CI. Product OverviewDONGFANG cylinder heads are third-party compatible replacement spare parts independently manufactured by DONGFANG, suitable for MAN series marine and industrial high-power diesel engines. They are widely used for maintenance and replacement of ocean-going vessel main engines, auxiliary engines, and large diesel engine units.The cylinder head is a core high-pressure load-bearing component of a diesel engine, continuously exposed to high-temperature combustion, high pressure, and alternating mechanical loads during operation. The product’s structural strength, sealing accuracy, and machining quality directly affect the overall power stability, combustion efficiency, and service life of the equipment.MAN high-power engine units are widely used in ocean transportation and heavy-duty industrial applications, requiring extremely high thermal fatigue resistance and structural stability from spare parts. DONGFANG develops products according to equipment assembly standards and adopts precision casting, heat treatment, and CNC precision machining processes, combined with comprehensive factory inspection, to provide stable replacement solutions for the global marine maintenance and power spare parts market.II. Compatibility Range and Application ScenariosCompatible with mainstream MAN high-power marine and industrial diesel engines.Precise one-to-one matching and assembly solutions can be provided according to customer engine models, part numbers, old parts, or drawings.Application scenarios:•Ocean-going vessel main propulsion power systems•Power equipment for large commercial vessels such as container ships, bulk carriers, and oil tankers•Marine auxiliary generator sets and backup power systems•Large industrial diesel generators and heavy-duty power unitsIII. Core Product Functions1. Stable Combustion Chamber Sealing for Smooth Power OutputThe high-strength sealing structure reliably withstands combustion pressure, maintains stable cylinder pressure, prevents pressure loss and gas leakage, and is suitable for long-term heavy-load operation of engine units.2. Optimized Intake and Exhaust Flow to Improve Combustion EfficiencyThe air passage structure is optimized to ensure sufficient gas exchange and smooth exhaust discharge, improving combustion conditions and reducing long-term operating energy consumption of the engine unit.3. Precision Fuel Injection Installation Structure for Stable Combustion ConditionsThe injector mounting position is precision-machined to ensure reliable positioning and sealing performance, maintaining uniform fuel atomization and reducing leakage and abnormal combustion failures.4. Balanced and Efficient Heat Dissipation to Reduce High-Temperature DamageThe internal optimized cooling water passages quickly dissipate combustion chamber heat, effectively reducing common problems such as thermal cracks, cylinder head deformation, and high-temperature fatigue.IV. Dual Material Options for Different Operating Conditions1. High-Strength Alloy Gray Cast IronIt provides good stability and high cost performance, suitable for routine maintenance and replacement of conventional marine vessels, marine auxiliary engines, and industrial generator sets.2. Compacted Graphite Iron (CGI)It provides higher strength, toughness, and thermal crack resistance, suitable for ocean-going main engines, high-power engine units, and harsh operating conditions involving long-term full-load continuous operation.V. Manufacturing Process•Resin sand precision casting ensures a well-formed internal structure with a low defect rate.•Artificial aging heat treatment releases internal stress, preventing deformation during long-term operation.•CNC precision machining is applied to core holes and sealing surfaces, ensuring high assembly accuracy.•Each individual product undergoes dimensional inspection, water pressure testing, air-tightness testing, and anti-corrosion/rust prevention treatment.Suitable for harsh operating conditions including marine environments with high salt spray, high humidity, and high loads.VI. Common Failure ReferenceCommon issues such as high-temperature thermal cracks, poor valve sealing, cooling passage corrosion and blockage, cylinder head surface deformation, injector area leakage, and power reduction can be effectively improved, significantly enhancing equipment stability.VII. Core Advantages of DONGFANG Products1. High Compatibility Direct Replacement, Shortening Maintenance TimeDimensions and parameters match equipment assembly standards, requiring no grinding or modification. Installation is convenient, reducing downtime losses.2. Special Optimization for Heavy-Duty Operating ConditionsThe structural strength and heat dissipation performance are optimized according to the characteristics of high-power and long-term continuous operation marine engines, providing stronger durability.3. Full Inspection Before Delivery, Stable and Controllable QualityEach product undergoes multiple inspections, including pressure testing, air-tightness testing, and dimensional inspection to prevent risks such as leakage, gas leakage, and assembly deviation.4. Flexible Supply and Customized ServicesSupports sample orders, small-batch orders, and large-volume orders. Private label customization services are available to meet global trade and maintenance procurement requirements.VIII. Application FieldsWidely used for maintenance of main engines of large vessels such as ocean-going container ships, bulk carriers, and oil tankers;Covers marine auxiliary engines, marine generator sets, and emergency backup power systems;Also suitable for replacement and maintenance of large industrial diesel generators and heavy-duty power units. Compliance DisclaimerThe MAN brand and model numbers mentioned on this page are only used to indicate the applicable equipment range of DONGFANG products and are provided for customer selection reference only.All DONGFANG cylinder heads are third-party aftermarket replacement parts independently designed, manufactured, and inspected by DONGFANG, and are not original products.Our company has no authorization, cooperation, affiliation, or OEM manufacturing relationship with the MAN brand. All trademarks belong to their respective rights holders and are used only for compatibility matching description purposes.

Compatible Models: ZC-G300, ZC-GN320, WX-G300, WX-X320, GC-320, GC-G320 I. Product OverviewDONGFANG cylinder heads are high-precision aftermarket replacement parts independently designed and manufactured by DONGFANG, suitable for various domestic diesel engines and widely used in maintenance scenarios for ships, construction machinery, agricultural machinery, and generator sets.The cylinder head is a core pressure-bearing combustion component of a diesel engine, continuously exposed to high-temperature and high-pressure combustion gas impact as well as mechanical loads during operation. Its structural strength, sealing performance, and machining accuracy directly determine the engine’s power performance, fuel consumption, and long-term operating stability.With the increasing application of domestic diesel engines in shipping and fishing, construction machinery, agricultural machinery, and industrial power generation, the market demand for highly compatible and reliable replacement cylinder heads continues to grow. Different engine manufacturers and models have significant differences in combustion chamber design, valve arrangement, fuel injection structure, and installation dimensions, requiring accurate model matching.Through complete engine measurement and reverse engineering based on original assembly dimensions, DONGFANG develops cylinder heads with precision casting, heat treatment stabilization, and CNC precision machining processes. Combined with standardized factory quality inspection, DONGFANG provides highly compatible and cost-effective domestic diesel engine cylinder head replacement solutions for global maintenance markets and spare parts distributors. II. Application Range and ScenariosDONGFANG provides customized replacement solutions for cylinder heads of various domestic diesel engines. Applicable equipment includes:•Various domestic marine diesel engines •Stationary/mobile diesel generator sets •Diesel power systems for construction machinery •Agricultural machinery powered by diesel engines •Other industrial stationary power units With flexible matching capabilities, we can perform one-to-one precise verification based on the engine model number, original part number, old cylinder head samples, engineering drawings, and installation dimensions provided by customers. Customized development is available according to requirements to ensure successful installation and application. III. Core Product Functions1. Sealed Combustion Chamber for Stable Power OutputTogether with the cylinder liner and piston, the cylinder head forms a complete sealed combustion chamber. It provides stable pressure-bearing performance, maintains compression pressure inside the cylinder, prevents power loss caused by pressure leakage, and ensures consistent diesel engine power output.2. Optimized Intake and Exhaust Flow for Improved Fuel EfficiencyThe internal intake and exhaust passages are optimized to ensure smooth air intake, gas exchange, and exhaust discharge. This improves combustion conditions, reduces unnecessary energy consumption, and lowers long-term fuel consumption.3. Stable Fuel Injection Structure for Improved Atomization and Combustion PerformanceThe injector mounting position is integrally precision-machined to ensure stable positioning and reliable sealing. It maintains stable fuel injection conditions, improves atomization performance, and helps prevent problems such as unstable combustion, carbon deposits, and difficult starting.4. Balanced and Efficient Heat Dissipation to Reduce High-Temperature DamageThe optimized internal cooling water passages efficiently circulate coolant to remove heat from the combustion chamber, reduce thermal stress, and effectively minimize common failures such as thermal cracks, cylinder head deformation, and valve burning. IV. Dual Material Options (Full Operating Condition Coverage)1. High-Strength Alloy Gray Cast Iron (Standard General-Purpose Version)Featuring stable casting performance, balanced wear resistance and heat resistance, and excellent machinability, it provides significant cost-performance advantages. It is suitable for routine maintenance of most domestic marine engines, generator sets, conventional agricultural machinery, and construction machinery.2. Compacted Graphite Iron CGI (Heavy-Duty Long-Life Version)With upgraded structural strength, toughness, thermal crack resistance, and high-temperature fatigue resistance, it is suitable for heavy-duty diesel engines that operate continuously under full load, experience large variations in working conditions, and require higher component service life. V. Precision Manufacturing Process•Resin sand precision casting is applied to ensure well-formed cooling passages, air passages, and combustion chamber cavities, reducing casting defects such as pores and sand inclusions from the source. •Artificial aging heat treatment is carried out to fully release internal casting stress, ensuring resistance to deformation and dimensional stability during long-term high-temperature operation. •CNC precision machining is performed on the fire deck surface, valve holes, injector holes, and engine mounting holes, with strict control of critical assembly tolerances. •Each finished product undergoes dimensional inspection, high-pressure water pressure testing, air-tightness sealing inspection, and professional anti-rust treatment. The products can reliably withstand harsh operating environments such as marine salt spray, construction site dust, and dusty and humid agricultural conditions. VI. Improvement of Common FailuresDONGFANG cylinder heads can effectively address common domestic diesel engine cylinder head problems, including:•Thermal cracks on combustion surfaces •Valve seat wear and gas leakage •Cooling water passage corrosion and blockage •Cylinder head surface deformation causing cylinder gasket failure •Insufficient cylinder pressure and increased fuel consumption They effectively extend engine maintenance intervals and improve overall service life. VII. Core Advantages of DONGFANG Products1. Accurate Measurement and Direct Replacement, Shortening Maintenance TimeDeveloped according to the assembly references of different engine models, the cylinder heads feature high matching accuracy for mounting holes, cooling passages, and air passages, eliminating the need for on-site grinding or modification and enabling faster equipment repair.2. Flexible Multi-Model Compatibility and Customized Development SupportConsidering the wide variety of domestic diesel engine models, DONGFANG supports customized development based on samples and drawings, covering both small-volume niche models and large-volume common models.3. Complete Quality Control System to Reduce Operating Failure RisksFrom raw casting to precision machining, pressure testing, and air-tightness inspection, the entire production process is strictly controlled. Quality risks such as leakage, air loss, and dimensional deviation are minimized to ensure more stable performance in maintenance applications worldwide.4. Flexible Supply Model with Private Label Customization SupportDONGFANG supports sample orders, small-batch replenishment, and large-volume orders. Private label customization services are also available to meet the long-term cooperation needs of spare parts distributors. VIII. Product Application FieldsMarine Field:Replacement and maintenance of main engines for various domestic vessels, including fishing boats, cargo ships, and engineering vessels.Power Generation Field:Maintenance and supporting applications for stationary industrial generator sets and emergency standby diesel power systems.Construction and Agricultural Machinery Field:Repair and replacement applications for diesel-powered equipment such as excavators, loaders, tractors, and other construction and agricultural machinery. Compliance DisclaimerThe domestic diesel engine models and part number information mentioned in this document are only used to indicate the applicable range of DONGFANG products and are provided solely as a reference for customer selection and compatibility verification.DONGFANG cylinder heads are third-party aftermarket replacement parts independently developed, manufactured, and inspected by DONGFANG. They are not original equipment manufacturer (OEM) parts from any diesel engine manufacturer.DONGFANG has no brand authorization, project cooperation, affiliation, or OEM manufacturing relationship with any original diesel engine brands mentioned. All trademarks and intellectual property rights belong to their respective owners and are used only for compatibility identification purposes.The products are intended only for compliant equipment maintenance and replacement. DONGFANG shall not be responsible for equipment damage or economic losses caused by unauthorized modifications, operation beyond specified conditions, or improper installation and maintenance.

Compatible Models: 6LUD-26、6LU-26AGHS、6LU-28、6LUN-28、6LUN-28AOA、6LUN-28ARG、6LU-32、6LU-35、6LUD-35、6LU-38、6LUS-38、6EL-30、6EL-32、6EL-35 I. Product OverviewDONGFANG cylinder heads are third-party maintenance replacement spare parts independently developed and manufactured by our company, suitable for maintenance applications of Hanshin marine diesel engines and related power equipment.The cylinder head is a core structural component of the diesel engine combustion system. It is installed on the upper part of the cylinder block and works together with the piston and cylinder liner to form a sealed combustion chamber. During continuous operation of the engine unit, the cylinder head is subjected to high-temperature and high-pressure combustion, cyclic thermal shocks, and mechanical loads for long periods. Material performance, structural strength, and machining accuracy directly determine the engine’s power performance and long-term operating reliability.Hanshin series diesel engines are widely used in marine propulsion systems and marine auxiliary engines. They have gained industry recognition due to their robust structure, convenient maintenance, and suitability for long-term continuous operation. Marine power equipment usually requires stable power output over extended periods; therefore, replacement cylinder heads need to have excellent thermal fatigue resistance, reliable sealing performance, and corrosion resistance suitable for marine operating conditions.DONGFANG cylinder heads are developed through measurement and mapping based on the original structures of corresponding engine models and mold development. They are manufactured using precision casting, heat treatment, and CNC precision machining processes. The product assembly dimensions, structural strength, and operating stability meet the maintenance and replacement requirements of marine diesel engines.II. Applicable Engine ModelsDONGFANG cylinder heads can match multiple Hanshin marine diesel engines and serve maintenance applications for marine propulsion systems, marine auxiliary diesel engines, marine generator sets, and industrial diesel power equipment.Applicable model list:6LUD-26, 6LU-26AGHS, 6LU-28, 6LUN-28, 6LUN-28AOA, 6LUN-28ARG, 6LU-32, 6LU-35, 6LUD-35, 6LU-38, 6LUS-38, 6EL-30, 6EL-32, 6EL-35Different engine models have significant differences in valve structures, combustion chamber designs, and cooling system layouts. Customers can provide engine models, original part numbers, physical samples, or drawings, and our company will assist in accurate matching to ensure that installation dimensions meet on-site assembly requirements.III. Main Functions of Cylinder HeadMaintain Combustion Chamber Sealing and Ensure Stable Marine Power OutputHanshin diesel engines are commonly used in marine power systems requiring long-term uninterrupted operation. The cylinder head withstands combustion pressure and maintains effective combustion chamber sealing, ensuring continuous and stable engine operation.Optimize Gas Exchange and Improve Fuel Combustion EfficiencyThe cylinder head integrates key components such as intake passages, exhaust passages, and valve seats. It precisely controls intake air and exhaust gas discharge, improves combustion efficiency, and enhances the operating economy of the engine unit.Support Fuel Injection Components and Ensure Stable Injection ConditionsThe injector mounting base on the cylinder head provides precise positioning and sealing capability, ensuring stable fuel injection, improving engine starting performance, and optimizing combustion results.Dissipate Combustion Heat and Improve Long-Term Operating StabilityThrough internal cooling water circulation passages, heat from the combustion area is effectively removed, reducing cylinder head thermal stress and minimizing risks of cracks, deformation, and other high-temperature damage caused by long-term operation under high temperatures.IV. Optional Material SolutionsBased on the operating conditions of Hanshin marine diesel engines, two mature material options are provided:High-Strength Alloy Gray Cast IronIt features good casting stability, balanced heat resistance and machinability, and outstanding cost performance.Applicable scenarios:Routine maintenance and replacement of Hanshin marine diesel engines and marine auxiliary power equipment.Compacted Graphite Iron (CGI)It provides higher mechanical strength, excellent thermal fatigue resistance, and crack resistance.Applicable scenarios:Marine diesel engines operating continuously for long periods under high-load conditions, effectively extending cylinder head service life.V. Manufacturing ProcessResin Sand Precision CastingPrecisely forms internal cooling water chambers, intake and exhaust passages, and internal reinforcement structures, improving casting quality and reducing casting defects such as pores and shrinkage cavities.Artificial Aging Heat TreatmentEliminates residual internal stress generated during casting, improves dimensional stability under long-term high-temperature operating conditions, and reduces thermal deformation.CNC Precision MachiningCompletes precision machining of the fire deck surface, valve holes, injector holes, and various mounting holes. Critical dimensions are matched according to the assembly standards of corresponding engine models.Anti-Rust Treatment and Complete InspectionFinished products undergo surface anti-rust treatment. Each unit sequentially completes dimensional inspection, water pressure resistance testing, and air-tightness testing to ensure stable sealing performance and adaptability to complex marine corrosion environments.VI. Common Failure ReferenceThermal Cracks on Combustion SurfaceCaused by long-term high-load operation of diesel engines, reduced cooling system efficiency, and concentrated cyclic thermal stress, which may affect combustion pressure stability.Valve Seat Wear / BurningLong-term exposure to high-temperature combustion gas impact causes reduced valve sealing performance, resulting in reduced power output and lower combustion efficiency.Cooling Water Chamber CorrosionThe combined effects of marine salt, coolant quality, and long-term operation may reduce cooling capacity and cause leakage in severe cases.Leakage at Injector Installation PositionCaused by sealing surface wear or insufficient machining accuracy, which may result in fuel leakage and abnormal engine operation.VII. Advantages of Choosing DONGFANG Cylinder HeadsDeveloped Through Original Engine Structure Measurement to Meet Maintenance Replacement RequirementsInstallation dimensions are verified and matched with high accuracy, reducing adjustment time during marine maintenance and enabling quick replacement.Specially Optimized for Long-Term Marine Operating ConditionsOptimization is carried out in material selection, machining accuracy, and sealing structure to enhance heat resistance and long-term operating reliability.Standardized and Complete Quality Inspection ProcessEach product undergoes casting appearance inspection, precision dimensional inspection, water pressure testing, and air-tightness testing to reduce operational and maintenance risks for end users.Flexible Supply ModelSupports sample confirmation, small-batch purchasing, and large-volume export supply, providing stable supply for long-term cooperating distributors.Customized and Private Label ServicesProducts can be developed according to customer drawings, samples, and technical requirements, supporting customized molds and private brand packaging solutions.VIII. Application FieldsMarine Main Propulsion Power SystemsSuitable for replacement and maintenance of Hanshin diesel engines installed on commercial ships, fishing vessels, engineering workboats, and inland waterway transport vessels.Marine Auxiliary Power EquipmentIncluding marine diesel generator sets, auxiliary diesel engine systems, and ship emergency power units.Industrial Diesel Power SystemsProvides reliable replacement spare parts for maintenance markets of various industrial diesel units operating continuously for long periods. Compliance DisclaimerDONGFANG cylinder heads are third-party repair replacement spare parts independently manufactured by the company and are not original Hanshin products. The company has no equity affiliation, brand authorization, OEM cooperation, or any other relationship with the Hanshin brand rights holder. The third-party trademarks mentioned herein are only used to objectively indicate the applicable engine models of the products, and all trademarks belong to their respective legal holders.

Compatible Models: R20, L20, R22, R25, R32I. Product OverviewDONGFANG cylinder heads are high-quality aftermarket replacement parts independently developed and manufactured by DONGFANG. They are compatible with Wartsila series marine diesel engines and large industrial power equipment, and are widely used in maintenance and replacement applications for ocean-going vessels, offshore engineering equipment, and diesel generator sets.The cylinder head is a core high-pressure combustion component of a diesel engine. It continuously withstands high temperatures, high-pressure impacts, and periodic mechanical loads during operation. The structural strength, heat dissipation capability, and sealing accuracy of the product directly determine the engine’s combustion efficiency, operating stability, and service life.Wartsila power equipment is well known for high efficiency, low energy consumption, and the ability to operate continuously under full load for long periods. It is widely applied in ocean transportation and offshore engineering equipment, which requires extremely high thermal fatigue resistance, deformation resistance, and long-term durability from spare parts.Based on independent process development and precision dimensional adaptation, DONGFANG adopts advanced casting, heat treatment stabilization, and CNC precision machining systems, combined with comprehensive factory inspections, to provide global marine maintenance companies, offshore engineering service providers, and power spare parts purchasers with highly reliable, highly compatible, and standardized replacement solutions.II. Compatible Models and Application ScenariosDONGFANG compatible cylinder heads are precisely suitable for mainstream Wartsila L-series and R-series marine diesel engines.Core Compatible Models:R20, L20, R22, R25, R32Application Scenarios:•Main propulsion power systems of ocean-going commercial vessels, cargo ships, and engineering vessels•Marine auxiliary diesel engines, marine generator sets, and emergency power equipment•Offshore engineering power systems and large industrial diesel generator setsThe product can be accurately matched one-to-one according to customer-provided engine model parameters, part numbers, old part samples, or technical documents, achieving non-destructive assembly replacement.III. Core Product Functions1. High-Load Sealing and Pressure Stability for Long-Term Reliable OperationDesigned for the long-term continuous operation characteristics of Wartsila units, the high-strength sealing structure provides stable pressure resistance, maintains balanced combustion chamber pressure, and ensures smooth and continuous power output of the complete engine.2. Optimized Intake and Exhaust Structure to Improve Fuel Utilization EfficiencyThe airflow field of the gas passages is scientifically optimized to ensure smooth gas exchange and complete exhaust discharge, effectively improving combustion efficiency, reducing fuel consumption, and meeting long-duration ocean navigation operating conditions.3. High-Precision Injector Positioning for More Stable Combustion ConditionsThe injector mounting seat is precision-machined as an integrated structure, providing accurate positioning and reliable sealing to ensure uniform fuel atomization and stable injection, preventing failures such as uneven combustion and power fluctuation.4. Efficient Circulating Heat Dissipation to Resist Thermal Fatigue DamageThe optimized internal cooling water passage layout provides efficient and balanced heat dissipation circulation, quickly removing combustion heat, and significantly reducing the risks of thermal cracks, cylinder head deformation, and local burning damage caused by long-term high-load operation.IV. Dual Material Selection for Different Operating Conditions (Full Coverage)1. High-Strength Alloy Gray Cast IronIt features excellent thermal stability, high machining accuracy, and good deformation resistance, with outstanding cost performance. It is suitable for routine maintenance and replacement of conventional marine auxiliary engines and industrial generator sets.2. Compacted Graphite Iron CGI (Designed for Ocean-Going Heavy-Duty Applications)It provides comprehensive improvements in strength, toughness, thermal crack resistance, and high-temperature fatigue resistance. It is specially designed for ocean-going vessels, offshore engineering equipment, and units operating continuously under full load in all-weather conditions, providing longer service life and lower repair frequency.V. Precision Manufacturing Process•The resin sand precision casting process ensures dense and well-formed internal structures of water passages, gas passages, and combustion chambers, reducing casting defects.•Artificial aging heat treatment releases internal stress, preventing dimensional deviation and structural deformation during long-term high-temperature operation.•Full-process CNC precision machining ensures accurate and controllable tolerances for fire deck surfaces, valve holes, injector holes, and mounting holes.•Each finished product undergoes dimensional inspection, high-pressure water pressure testing, air-tightness sealing testing, and anti-corrosion/rust prevention treatment.Perfectly suitable for harsh operating conditions including high salt spray, high humidity, and long-term heavy-load marine environments.VI. Improvement of Common FailuresCommon issues such as high-temperature thermal cracks, reduced valve seat sealing performance, cooling water passage corrosion and blockage, cylinder head surface deformation, injector area leakage, and reduced power output under long-term load can be effectively improved, significantly enhancing equipment operating stability.VII. Core Advantages of DONGFANG Products1. High Compatibility Direct Installation, Greatly Shortening DowntimeStrictly matched with equipment assembly references, with mounting holes, water passages, and gas passages fully compatible. No grinding or modification is required, providing high on-site replacement efficiency.2. Special Optimization for Wartsila Long-Life Operating ConditionsDesigned according to the requirements of low energy consumption, long-term operation, and high stability of Wartsila engines, enhancing thermal fatigue resistance and sealing durability to meet demanding ocean-going operating conditions.3. Strict Full-Process Quality Control, Lower Quality RisksFrom raw casting and precision machining to pressure and air-tightness testing, every product undergoes complete inspection before delivery, preventing quality issues such as gas leakage, water leakage, and assembly deviation.4. Flexible Supply + Private Label Customization ServiceSupports sample trial orders, small-batch replenishment, and large-volume stock delivery. Private brand customization services are available to meet the diverse procurement needs of global offshore engineering and marine maintenance companies.VIII. Product Application FieldsWidely compatible with maintenance and replacement of main engines for large vessels such as ocean-going cargo ships, commercial vessels, and engineering ships;Suitable for maintenance of various marine auxiliary engines, marine generator sets, and emergency backup power systems;Also covers supporting applications for large industrial diesel generators and offshore engineering power equipment maintenance. Compliance Disclaimer The Wartsila brand and model numbers mentioned on this page are only used to describe the applicable equipment range of DONGFANG products and are provided solely as a reference for customer selection.All DONGFANG cylinder heads are third-party aftermarket replacement parts independently designed, manufactured, and inspected by DONGFANG, and are not original equipment manufacturer (OEM) parts.DONGFANG has no authorization, cooperation, affiliation, or OEM manufacturing relationship with the Wartsila brand. All trademarks belong to their respective owners and are only used for compatibility identification purposes.

Compatible Models: MG25BX, L25BX, M26, M28DHS, M28X, M28ZE, 6M-31FZ, 6M-31EZ, 6M-31AFTE, 6M-37XI. Product OverviewDONGFANG cylinder heads are high-quality aftermarket replacement parts independently manufactured by DONGFANG. They are widely compatible with Niigata series marine diesel engines and industrial diesel power equipment, and are suitable for routine maintenance and failure replacement of marine main engines, auxiliary engines, and diesel engine units.The cylinder head is a key component of a diesel engine for pressure bearing, sealing, and heat exchange. It continuously withstands high combustion pressure, alternating temperature loads, and continuous mechanical vibration during operation. The product's sealing performance, structural stability, and machining accuracy directly determine the overall operating smoothness, combustion efficiency, and service life of the equipment.Niigata power equipment is known for stable operation, low failure rates, and suitability for long-term continuous operation. It is widely used in various commercial vessels, engineering vessels, fishing vessels, and industrial power generation equipment, which have strict requirements for spare part thermal stability and sealing reliability.Through independent measurement and mapping as well as process optimization, DONGFANG develops compatible cylinder heads according to equipment assembly standards. The products are manufactured using precision casting, heat treatment stabilization, and CNC precision machining processes, combined with complete factory inspections, providing highly stable and cost-effective replacement solutions for global marine maintenance companies and power spare parts markets.II. Compatible Models and Application ScenariosDONGFANG compatible cylinder heads can accurately match mainstream Niigata marine and industrial diesel engine series.Core compatible models:MG25BX, L25BX, M26, M28DHS, M28X, M28ZE, 6M-31FZ, 6M-31EZ, 6M-31AFTE, 6M-37XApplication scenarios:•Main propulsion power systems of commercial vessels, fishing vessels, engineering vessels, and inland waterway vessels•Marine diesel generator sets, auxiliary diesel engines, and backup power equipment•Industrial stationary diesel power generation and power unitsThe products can be accurately matched one-to-one according to customer-provided engine model information, part numbers, old parts, or drawings, ensuring proper assembly fit without modification.III. Core Product Functions1. Stable Combustion Chamber Pressure to Ensure Reliable Continuous OperationThe precision sealing structure maintains stable cylinder pressure and prevents pressure fluctuations, allowing the engine to operate more smoothly during long-term continuous operation.2. Optimized Intake and Exhaust Circulation to Improve Combustion EfficiencyThe air passage structure is scientifically optimized to ensure sufficient gas exchange and smooth exhaust discharge, effectively improving combustion conditions, reducing energy consumption, and enhancing overall operating stability.3. High-Precision Injector Installation Structure for More Uniform and Stable CombustionThe injector seat is precision-machined with reliable sealing performance, ensuring uniform fuel atomization and preventing problems such as injector leakage, unstable combustion, and unstable power output.4. Balanced and Efficient Heat Dissipation to Reduce Thermal Fatigue DamageThe optimized internal cooling water circulation system provides uniform and efficient cooling, quickly removing combustion heat and significantly reducing common failures such as thermal cracks, local deformation, and high-temperature aging.IV. Dual Material Options (Full Operating Condition Coverage)1. High-Strength Alloy Gray Cast IronIt provides stable heat resistance, balanced structure, and high cost performance. It is suitable for routine maintenance and replacement of conventional vessels, auxiliary engines, and industrial power units.2. Compacted Graphite Iron (CGI)It provides significantly improved strength, toughness, thermal crack resistance, and fatigue resistance. It is suitable for equipment operating continuously under high loads without shutdown, greatly extending spare part service life and reducing repair frequency.V. Precision Manufacturing Process•Resin sand precision casting ensures well-formed internal water passages and air passages, with fewer casting defects and high consistency.•Artificial aging heat treatment releases internal stress, preventing deformation during long-term high-temperature operation.•Full-size CNC precision machining ensures consistent accuracy of the fire deck surface, valve holes, injector holes, and mounting holes, with controllable tolerances.•Each finished product undergoes dimensional inspection, high-pressure water pressure testing, air-tightness testing, and anti-rust and anti-corrosion treatment.Fully suitable for harsh operating conditions including high humidity, high salt spray marine environments, and industrial dusty environments.VI. Improvement of Common FailuresIt can effectively solve common Niigata diesel engine problems, including:•Thermal cracks on combustion surfaces;•Valve seat wear and poor sealing;•Cooling water passage scaling and corrosion;•Cylinder head surface deformation;•Injector area leakage;•Power reduction caused by long-term operation.It significantly improves equipment operating stability.VII. Core Advantages of DONGFANG Products1. High Compatibility Direct Replacement, Shortening DowntimeDeveloped strictly according to equipment assembly standards, with precise matching of mounting holes, water passages, and air passages. No grinding or modification is required, making installation fast and convenient.2. Special Optimization for Niigata Stable Operating ConditionsDesigned according to the characteristics of Niigata engines featuring long-term continuous operation, low failure rates, and high stability, enhancing thermal fatigue resistance and sealing durability.3. Full-Process Quality Control and Complete Factory InspectionFrom casting and machining to pressure resistance and air-tightness testing, all processes are independently inspected to prevent quality issues such as gas leakage, water leakage, and assembly deviation.4. Flexible Supply + Private Label Customization ServicesSupports sample trial orders, small-batch replenishment, and large-volume stock supply. Private brand customization services are available to meet global trade and maintenance procurement requirements.VIII. Product Application FieldsWidely compatible with maintenance and replacement applications for main engines of various commercial vessels, fishing vessels, engineering vessels, and inland waterway vessels;Suitable for maintenance of marine generator sets, auxiliary diesel engines, and vessel backup power systems;Also suitable for repair and replacement applications of industrial diesel generators and stationary power units. Compliance Disclaimer The Niigata brand and model numbers mentioned on this page are only used for product compatibility description and are provided solely as a reference for customer selection.All DONGFANG cylinder heads are third-party aftermarket replacement parts independently designed, manufactured, and inspected by DONGFANG, and are not original equipment manufacturer (OEM) parts.DONGFANG has no authorization, cooperation, affiliation, or OEM manufacturing relationship with the Niigata brand. All trademarks belong to their respective owners and are used only for compatibility matching purposes.

Models: A24R、H27A、AH28、AH28A、AH33、A31、DM33、DM38、AH38 I. Product OverviewDONGFANG cylinder heads are third-party compatible replacement spare parts independently manufactured by DONGFANG, suitable for Akasaka marine diesel engines and widely used for maintenance and replacement of marine main engines, auxiliary engines, and power equipment.The cylinder head is a core high-pressure load-bearing component of a diesel engine, continuously exposed to high-temperature combustion, high pressure, and alternating mechanical loads. The sealing accuracy, structural strength, and machining quality of the product directly affect the power stability and service life of the entire engine.Relying on precision measurement, process optimization, and a standardized quality inspection system, DONGFANG cylinder heads can meet the requirements for stable replacement under marine operating conditions with high salt, high humidity, and continuous operation.II. Compatibility Range and Application ScenariosCompatible with Akasaka A, AH, and DM series marine diesel engines.Application scenarios:•Main propulsion systems of commercial ships and cargo vessels•Marine auxiliary diesel engines and ship generator sets•Offshore engineering and industrial diesel power equipmentThe assembly dimensions can be accurately matched one-to-one according to the customer’s engine model, part number, old parts, or drawings, achieving non-destructive replacement.III. Core Product Functions1. Stable Combustion Chamber Sealing for Smooth Power OutputMaintains stable cylinder pressure, prevents pressure loss and gas leakage, and ensures continuous and stable operation of the power unit.2. Optimized Intake and Exhaust Efficiency to Reduce Operating Energy ConsumptionThe air passage structure is reasonably designed to ensure smooth gas exchange, improve fuel combustion efficiency, and reduce power loss.3. Precision Fuel Injection Installation Structure for Stable Combustion ConditionsThe injector holes are precision-machined to ensure reliable positioning and sealing, preventing failures such as fuel leakage and abnormal combustion.4. Efficient Circulating Heat Dissipation to Resist High-Temperature DamageThe cooling water passage structure is optimized to improve heat dissipation efficiency and effectively reduce the risks of thermal cracks, cylinder head deformation, and high-temperature fatigue.IV. Dual Material Options for Different Operating Conditions1. High-Strength Alloy Gray Cast IronStable performance and high cost-effectiveness, suitable for routine maintenance of conventional marine auxiliary engines and standard operating conditions.2. Compacted Graphite Iron (CGI)Featuring higher strength, toughness, and thermal crack resistance, it is suitable for ocean-going main engines and long-term full-load continuous operating conditions.V. Manufacturing Process•Resin sand precision casting ensures a dense and well-formed internal structure with a low defect rate.•Artificial aging heat treatment eliminates internal stress and prevents deformation during long-term operation.•CNC precision machining is applied to core holes and sealing surfaces, ensuring high assembly accuracy.•Each individual product undergoes independent dimensional inspection, water pressure testing, air-tightness testing, and anti-corrosion treatment.Suitable for harsh marine environments with high salt spray and high humidity.VI. Improvement of Common FailuresIt can effectively improve common problems such as high-temperature cracks, valve sealing failure, cooling water passage corrosion, cylinder head deformation, and combustion gas leakage, enhancing equipment operating stability.VII. Core Advantages of DONGFANG Products1. High Compatibility Direct Replacement, Shortening Maintenance TimeDimensions accurately match assembly standards, eliminating the need for grinding or modification and reducing downtime and maintenance losses.2. Optimized for Marine Operating ConditionsThe structural strength and environmental resistance are optimized for highly corrosive and high-load marine operating conditions, providing stronger durability.3. Full Inspection Before Delivery, Stable QualityEach product undergoes multiple inspections, including water pressure testing, air-tightness testing, and dimensional inspection to avoid risks such as leakage, gas leakage, and assembly deviation.4. Flexible Supply and Customized ServicesSupports sample orders, small-batch orders, and large-volume orders. Private labeling and customized production based on drawings or old parts are also available.VIII. Application FieldsWidely applicable to maintenance of main engines for various commercial ships, cargo vessels, fishing vessels, and engineering vessels;Covers marine auxiliary engines, generator sets, and emergency backup power systems;Suitable for maintenance and replacement applications of industrial power equipment equipped with Akasaka diesel engines. Compliance Disclaimer This product is a third-party compatible replacement spare part independently manufactured by DONGFANG and is not an original Akasaka product. Our company has no affiliation, authorization, or cooperation relationship with the Akasaka brand owner. All trademarks mentioned herein belong to their respective legal rights holders and are only used to indicate the applicable engine models of the product.

Models: UEC 45/75C, UEC 45/80D, UEC 37/88H, UEC 45/80D, UEC 37LAI. Product OverviewDONGFANG cylinder head is a high-precision replacement component developed for large marine low-speed diesel engines. It is compatible with Kobe UEC series low-speed diesel engines and is widely used in maintenance scenarios for large vessel main propulsion systems and related power equipment.As a core component of the combustion chamber of a diesel engine, the cylinder head is installed on the top of the cylinder and continuously withstands high temperature and high pressure generated during combustion, and cyclic mechanical loads. Low-speed marine diesel engines need to maintain stable speed and continuous power output for long periods, placing strict requirements on the cylinder head’s pressure-bearing capability, combustion chamber sealing performance, cooling efficiency, and long-term dimensional stability.Kobe UEC series diesel engines are mainly used in large vessel propulsion applications. They feature low-speed operation, high efficiency, and long-term continuous working capability. Compared with medium and high-speed diesel engines, their cylinder heads need to withstand longer combustion cycles and more complex thermal load variations. Therefore, higher standards are required for material strength, thermal fatigue performance, and machining accuracy.DONGFANG brand cylinder heads are independently designed and developed based on the assembly dimension requirements of corresponding engine models. They are manufactured using high-strength casting materials, precision machining processes, and strict inspection procedures, providing stable and reliable third-party replacement solutions for ship repair companies, engine service providers, and diesel engine spare parts suppliers.II. Product Compatible ModelsDONGFANG provides professional cylinder head products compatible with marine diesel engines, mainly covering the following models:UEC 45/75C, UEC 45/80D, UEC 37/88H, UEC 37LA, and other low-speed diesel engine models.The above compatible models are mainly applied in: • Main propulsion systems of large commercial vessels; • Ocean-going vessels; • Marine low-speed diesel power equipment; • Large vessel maintenance spare parts markets. Due to differences among UEC series diesel engine models in cylinder bore dimensions, combustion chamber structures, cooling system layouts, and valve configurations, DONGFANG can perform precise matching verification based on the engine model, part number, product photos, or technical documents provided by customers, ensuring that the cylinder head meets actual assembly and operating requirements.III. Core Product FunctionsCompatible with High-Pressure Combustion Conditions of Low-Speed Marine Engines to Ensure Stable Main Engine OperationCompatible with UEC series marine propulsion diesel engines, the cylinder head can withstand continuous combustion pressure. By maintaining stable combustion chamber sealing, it ensures reliable propulsion power output of the main engine and meets vessel navigation requirements.Match Low-Speed Diesel Engine Structures and Optimize Combustion EfficiencyThe product integrates intake and exhaust passages, valve installation structures, and fuel injection component mounting positions. It optimizes gas exchange processes, improves combustion efficiency, and enhances the operating economy of large marine engines.Ensure Fuel Injection System Installation Accuracy and Maintain Stable CombustionDesigned according to the fuel injection precision requirements of low-speed marine diesel engines, the injector installation structure maintains accurate positioning, ensuring effective fuel atomization and stable combustion processes.Control Long-Term Operating Thermal Loads and Extend Product Service LifeDesigned for continuous operation during ocean voyages, the internal cooling structure effectively controls heat in high-temperature areas, reduces the risk of thermal cracks and fatigue damage, and improves product durability.IV. Product Material SelectionConsidering the long-term continuous operating characteristics of UEC series low-speed diesel engines, DONGFANG provides material solutions suitable for different operating conditions:High-strength alloy gray cast iron:Provides good heat resistance, vibration resistance, and machining stability, suitable for conventional marine power system maintenance and replacement requirements.Compacted Graphite Iron (CGI):Provides higher strength, thermal fatigue resistance, and crack resistance. It is suitable for large vessel main engines and low-speed diesel power equipment operating continuously for long periods, improving service life under high-temperature cyclic conditions.V. Product Manufacturing ProcessDONGFANG cylinder heads are manufactured using resin sand precision casting technology. Based on the structural characteristics of compatible engine models, the combustion chamber area, cooling water chambers, and internal passages are cast to improve overall casting stability.Through artificial aging heat treatment, internal casting stress is eliminated to ensure good dimensional stability during long-term vessel operation.CNC precision machining technology is applied to process the fire deck surface, valve holes, injector mounting holes, and connection areas, ensuring that critical dimensions meet assembly requirements.Each product undergoes dimensional inspection, water pressure testing, air-tightness testing, and anti-rust treatment before delivery, improving reliability in marine environments with high salt spray conditions.VI. Common Cylinder Head Failures and CausesCombustion Surface CracksUsually caused by long-term high-temperature combustion, thermal cycle variations, and insufficient cooling in low-speed diesel engines, affecting combustion chamber sealing performance.Exhaust Valve Area DamageLong-term exposure to high-temperature combustion gas erosion may reduce valve seat sealing capability and decrease engine operating efficiency.Cooling Water Chamber Corrosion or ScalingAffected by seawater environment, water quality, and cooling system maintenance conditions, which may result in reduced heat dissipation capability.Abnormal Cylinder Head Sealing SurfaceAfter long-term operation, thermal deformation and changes in installation stress may occur, potentially causing combustion gas leakage or sealing failure.VII. Advantages of Choosing DONGFANG ProductsDONGFANG cylinder heads are specially developed according to the assembly requirements of UEC series diesel engines, ensuring product dimensional compatibility and meeting marine maintenance replacement requirements.Based on the characteristics of long-term continuous operation of low-speed marine diesel engines, DONGFANG optimizes material selection, thermal stability, and sealing performance to improve reliability under complex marine environments.With strict quality control throughout the entire process, all products undergo casting inspection, dimensional inspection, water pressure testing, and air-tightness testing, effectively reducing customer maintenance risks and downtime costs.DONGFANG supports sample confirmation, small-batch purchasing, batch supply, and OEM customized production. Customized product solutions can be provided according to customer drawings, old parts, or technical parameters.VIII. Product Application FieldsDONGFANG cylinder heads are mainly compatible with large vessel low-speed main propulsion diesel engine systems, including:•Ocean-going cargo vessels;•Bulk carriers;•Container ships;•Engineering transport vessels.They are also suitable for marine auxiliary power systems, including:•Marine power generation equipment;•Auxiliary diesel engines;•Vessel maintenance spare parts.The products serve the global marine maintenance market and provide reliable replacement options for users with compatible diesel engines. Compliance DisclaimerThis product is a third-party compatible replacement part independently produced by DONGFANG and is not an original product of KOBE. Our company has no affiliation, authorization, or cooperation relationship with the KOBE brand owner. All trademarks mentioned in this document belong to their respective legal rights holders and are used only to indicate the applicable engine models of this product.

Compatible Models: 453, 453C, 250I. Product OverviewDONGFANG cylinder heads are third-party compatible replacement parts independently developed by DONGFANG, serving maintenance applications for MaK marine diesel engines and industrial power equipment. DONGFANG provides stable and cost-effective spare parts solutions for the global marine maintenance and power parts market.The cylinder head is a core pressure-bearing component of the diesel engine combustion chamber. It continuously withstands explosive high pressure, high-temperature gas erosion, and alternating mechanical loads during operation. Its structural strength and machining accuracy directly determine engine power performance, fuel consumption, and maintenance cycle.MaK diesel engines are widely used in marine propulsion, marine power generation, and industrial stationary power equipment due to their stable durability and adaptability to various operating conditions. They have strict requirements for cylinder head strength, heat dissipation performance, and assembly accuracy.Based on independent measurement and forward development, DONGFANG combines experience in marine engine operating conditions with precision casting, CNC precision machining processes, and standardized quality inspection to achieve non-destructive replacement of compatible engine models.II. Compatible Models and Application ScenariosMain compatible models:MaK 453, MaK 453C, MaK 250Application scenarios:•Marine main propulsion power systems•Marine auxiliary / emergency generator sets•Industrial stationary diesel power equipmentDifferent engine models have differences in combustion chamber, cooling water passage, and air passage structures. We can provide one-to-one customized matching solutions based on the engine model, original part number, or old part samples provided by customers, ensuring tight assembly and stable operation.III. Core Functions1. Stable Combustion Chamber Sealing for Smooth Power OutputThe independently developed sealing structure maintains stable cylinder compression pressure, prevents gas leakage and pressure loss, ensures complete combustion and stable power output, and meets the requirements of MaK units operating continuously for long periods.2. Optimized Intake and Exhaust Passages to Reduce Operating Energy ConsumptionThe air passage structure is optimized and upgraded to improve gas exchange efficiency, reduce energy loss, and lower long-term fuel operating costs of the engine unit.3. High-Precision Injector Base for Controllable Combustion ConditionsThe injector mounting position is integrally precision-machined with excellent positioning and sealing performance. It matches MaK fuel injection structure standards and prevents problems such as fuel leakage and abnormal combustion.4. Optimized Cooling Water Passages for Efficient Heat Dissipation and Resistance to Continuous Heavy-Load Thermal DamageThe customized cooling water passage layout quickly transfers combustion residual heat, reduces thermal deformation and thermal cracks caused by alternating hot and cold conditions, and is suitable for long-term heavy-load operation of marine and industrial equipment.IV. Dual Material Options1. High-Strength Alloy Gray Cast Iron (Conventional Operating Conditions)It provides balanced wear resistance, heat resistance, and thermal fatigue resistance with high cost performance. It is suitable for daily maintenance of marine auxiliary engines and conventional industrial power units.2. Compacted Graphite Iron CGI (Heavy-Duty Harsh Operating Conditions)Strength, toughness, and thermal fatigue resistance are comprehensively upgraded. It can withstand long-term full-load operation, large load fluctuations, and high salt spray marine environments. It is suitable for heavy-duty models such as marine propulsion engines, extending spare part service life and reducing overall maintenance costs.V. Standardized Manufacturing Process1.Resin sand precision integrated casting forms dense cooling passages, air passages, and combustion chamber structures, reducing casting defects such as pores and sand holes from the source.2.Artificial aging heat treatment eliminates casting internal stress, preventing deformation during long-term high-temperature operation and maintaining long-term dimensional accuracy.3.CNC precision machining is applied to all core holes and sealing surfaces, with strict control of assembly tolerances to support non-destructive alignment installation.4.Each finished product undergoes dimensional verification, high-pressure water pressure testing, and air-tightness inspection, combined with anti-corrosion and rust-prevention treatment, making it suitable for harsh environments such as marine salt spray and industrial dust.VI. Common Failure AnalysisFrequent cylinder head failures are mainly caused by thermal fatigue, insufficient maintenance, and insufficient component accuracy:•Thermal cycling stress concentration causes cracks and fractures on the combustion surface, damaging combustion chamber sealing performance;•Long-term high-temperature erosion wears valve seats, causing sealing failure, reduced power output, and increased fuel consumption;•Poor water quality and insufficient maintenance cause cooling passage scaling and corrosion, sharply reducing heat dissipation efficiency and worsening thermal damage;•Insufficient machining accuracy causes injector hole sealing failure, resulting in fuel leakage, carbon deposits, and unstable combustion.VII. Core Advantages of DONGFANG Products1. Precise Direct Installation Without ModificationDeveloped according to MaK engine assembly parameters through measurement and mapping, the mounting holes, cooling passages, and air passages are fully matched. No on-site grinding or modification is required, shortening vessel downtime and maintenance periods.2. Condition-Oriented OptimizationThe heat dissipation, toughness, and sealing performance are optimized according to the operating challenges of MaK units, helping to address industry issues such as long delivery times and high procurement costs of original spare parts.3. Full-Process Quality ControlThe entire process from raw materials to finished products is independently controlled. Water pressure testing, air-tightness testing, and dimensional inspection are mandatory. Risks such as leakage, gas leakage, and dimensional deviation are controllable, with lower failure rates under harsh operating conditions.4. Flexible Supply and CustomizationSupports trial samples, batch stock supply, and OEM private label production. Customized solutions can be developed based on drawings or old parts to meet the procurement requirements of global maintenance companies, operators, and spare parts suppliers.VIII. Application Fields•Maintenance of main engines for commercial ships, cargo vessels, engineering vessels, and other ships;•Supporting maintenance of marine auxiliary engines and emergency generator sets;Maintenance market for industrial diesel equipment powered by MaK engines. Compliance DisclaimerThe Mak brand and corresponding model numbers mentioned in this document are only used to accurately indicate the applicable model range of DONGFANG brand products and are provided for customer selection reference only. All products on this page are professional aftermarket compatible replacement parts independently designed, produced, and quality-controlled by DONGFANG. They are not original products, not officially authorized products of the brand, and have no cooperation, affiliation, or authorization relationship with the brand or its original manufacturer. They do not constitute any brand affiliation, infringement, or commitment to original manufacturer quality.The products are only applicable to compliant equipment maintenance and replacement scenarios. We shall not be responsible for any equipment damage caused by improper installation, unauthorized modification, operation beyond applicable working conditions, or improper maintenance. All performance data and descriptions on this page are provided as references under normal operating conditions and do not constitute any contractual validity or warranty commitment.