Details
Weichai X6170ZC756-5 Marine Diesel Engine (756 HP, 1500 RPM)
The Weichai X6170ZC756-5 marine engine is a proven medium-speed propulsion solution developed for commercial vessels that require dependable performance, fuel economy, and long operating life. Rated at 756 HP (556 kW) at 1500 RPM, this engine belongs to the renowned Weichai 170 Series Marine Diesel family and is widely used as a marine main engine in fishing vessels, tugboats, inland transport vessels, engineering ships, and cargo carriers.
Built around a robust 6-cylinder inline platform with a displacement of 27.24 liters, the Weichai X6170ZC756-5 combines strong low-speed torque with stable continuous-duty operation. Its heavy-duty design allows vessel owners to achieve reliable propulsion performance while maintaining low operating costs throughout the engine lifecycle.
As an experienced engine supplier, HekoPower provides genuine Weichai marine engines, technical support, spare parts supply, and export services for customers worldwide.
Tech Specs of Weichai X6170ZC756-5
General Engine Data
Engine Model: Weichai X6170ZC756-5
Cylinder Count: 6 / 8 Cylinders in Line
Engine Type: 4-stroke, water cooled, in-line, turbocharged and aftercooled
Total Engine Displacement: 27.24 L / 36.32 L
Bore * Stroke: 170×200 (mm)
Dimensions L×W×H) / net weight: L6 2463×1200×1650 (mm) / 3100kg; L8 2650×1040×1818 (mm) / 3800kg
Key Performance Data
Rated Power: 556 kW / 756 HP
Rated Speed: 1500 RPM
Idle Speed: 450-650 RPM
Minimum fuel consumption rate: 197 g/kW.h
Oil consumption rate: ≤0.5 g/kW.h
Torque reserve: 20-34%
More Technical Data
Certification: IMO Tier II
Aspiration: turbocharged and aftercooled
Starting system: Gas/Electrical
Rotation(facing the flywheel) : Counter-clockwise
Fuel system: Mechanical pump
Power rating: P1
Noise: ≤105 dB(A)
Technical Positioning and Platform Comparison
Structural Design Differentiation
The X6170ZC756-5 diesel engine utilizes a specialized gantry-type cast-iron cylinder block that separates it from standard high-speed commercial marine diesel units. High-speed marine engines often use lightweight alloy matrices or split-crankcase designs to save weight. In contrast, this Weichai marine propulsion engine features an integrated block construction with high structural rigidity. This design allows it to comfortably absorb the peak combustion pressures generated during maximum torque output.
The structural foundation includes separate cast-iron cylinder heads, implementing a clean "one head per cylinder" design philosophy. If a single cylinder experiences an thermal or mechanical issue, fleet mechanics can service that individual head assembly without disturbing the remaining five cylinders. This minimizes maintenance footprint and lowers downtime during overhauls.
Combustion and Air Management
Air handling on the Weichai 756 HP marine engine relies on a custom-matched pulse-conversion turbocharger paired with a high-capacity jacket-water intercooler. Many alternative commercial marine engines utilize constant-pressure turbocharging systems, which offer good efficiency at a single fixed peak operating point but experience significant turbo lag at lower engine speeds. The pulse-conversion system on the Weichai 6170 series propulsion engine leverages the kinetic energy of individual cylinder exhaust gas pulses. This design speeds up compressor wheel acceleration across a broad operating band.
This air charging configuration matches perfectly with an optimized four-valve cylinder head design. Providing two intake and two exhaust valves per cylinder ensures lower flow resistance, allowing a larger volume of clean air to enter the combustion bowl. This configuration achieves an exceptionally complete fuel burn, lowering smoke density values and keeping the minimum fuel consumption rate down to a highly competitive 197 g/kW·h.
Mechanical Injection System Engineering
The fuel delivery framework relies on a traditional, mechanically governed P-type in-line injection pump coupled with multi-hole mechanical injectors. While electronic common-rail marine power solution layouts offer precise injection timing control, they introduce vulnerable electronic control units, complex wiring harnesses, and sensitive solenoid valves that are susceptible to damage from salt spray, humidity, and voltage fluctuations.
The mechanical pump architecture used on the Weichai X6170 marine engine ensures complete electrical independence during operation. Once started via the 24V electric motor or optional air starter system, the engine requires zero external electrical power to maintain continuous propulsion. This makes it an incredibly reliable platform for long-range offshore vessels where electrical system failures cannot be allowed to compromise primary vessel propulsion.
Operational Scenarios and Vessel Applications
Deep-Sea Fishing Vessel Operations
The Weichai fishing vessel engine configuration fits the operational profile of deep-sea trawlers and long-liners perfectly. These vessels demand an engine capable of handling two completely different operational modes seamlessly. First, they need high transit speeds to reach distant fishing grounds quickly. Second, they require high low-speed torque while dragging heavy trawl nets through the water at low speeds.
The Weichai 556kw propulsion engine features a broad torque reserve ranging from 20% to 34%. This substantial torque backup prevents the engine from lugging down or stalling when a net catches a heavy current or encounters a sudden bottom obstruction. This high torque capacity ensures steady, predictable hull control when handling heavy loads.
Commercial Tugboat and Pushboat Propulsion
For harbor operations and coastal towing, the Weichai tugboat propulsion engine layout delivers the continuous bollard pull necessary to maneuver large cargo hulls. Tugboats require rapid thrust adjustments and frequent shifting between ahead and astern modes, placing heavy thermal loads on the piston tops and cylinder liners.
The X6170ZC756-5 handles these rapid load changes using an internal gallery oil-cooled aluminum piston design. A high-flow lubrication pump forces oil through a dedicated channel inside the piston crown, pulling heat away from the top ring groove to prevent piston ring sticking and liner scuffing. This comprehensive thermal management keeps the engine reliable during demanding harbor docking operations.
Coastal and Inland River Cargo Transporters
On long-distance inland waterways and coastal shipping lanes, economic performance determines profitability. Operating as a dedicated Weichai cargo ship diesel engine, the 27.24L displacement platform provides the mechanical efficiency needed for long runs.
The engine is officially rated for Weichai X6170 series P1 continuous duty propulsion. This rating permits unrestricted operation at 100% full load for unlimited hours per year, with an expected engine overhaul lifespan of 20,000 operational hours. For cargo operators, this long service life translates directly into lower operating costs per ton-mile and predictable maintenance intervals.
Wholesale Supply Logistics and Component Sourcing
Procurement Sourcing Channels
As an established Weichai X6170ZC756-5 supplier and exporter, HekoPower maintains a direct commercial supply network that ensures vessel operators receive fully certified propulsion assets. The global marine market frequently contains unverified component builds and mixed-specification industrial engine conversions that lack the necessary marine-grade water pumps, shielded exhaust manifolds, and marine classification approvals.
Sourcing through a dedicated China Weichai marine engine manufacturer distribution channel ensures that every single power unit is built from the ground up for marine applications. These units come complete with factory-installed marine accessories, proper documentation, and type-approval certifications from major international classification societies.
Parts Compatibility Management
Maintaining fleet operational readiness requires rapid access to correct component listings. When searching for Weichai X6170ZC756-5 engine parts, using precise model identification numbers prevents parts mismatch errors. The Weichai 170 base platform has evolved through several design generations, meaning components from older 170Z or standard X6170 configurations may not fit the precise valve guides, injector nozzles, or turbocharger linkages used on this specific IMO Tier II certified marine engine.
HekoPower manages verified parts inventories, tracking exact component cross-references to ensure that replacement gaskets, injection lines, and filtration elements match your specific engine build.
Marine Engine Maintenance and Overhaul Guidelines
Injection System Calibration
The mechanical P-type injection pump requires clean fuel to prevent premature wear on its internal plungers and delivery valves. Marine diesel fuel often carries water contamination from tank condensation and fuel transfers. This water can quickly score high-pressure injection components if not properly filtered out.
Operators must check the duplex fuel filters daily and drain any accumulated water from the primary separator bowls. Every 2,000 operating hours, the injection nozzles should be removed and tested on a pressure bench to check their spray patterns and opening pressures. This regular maintenance prevents poor atomization, which can cause unburnt fuel to wash down the cylinder liners and dilute the crankcase oil.
Cooling Circuit Zinc Anode Replacement
The heat exchanger configuration utilizes a dual-circuit cooling design where fresh water cools the internal engine components, and raw sea water passes through a tube bundle to cool the fresh water circuit. This raw water circuit is highly vulnerable to galvanic corrosion caused by the interaction of different metals in salt water.
To protect the heat exchanger housings and raw water pump impellers, sacrificial zinc anodes are placed inside the raw water passage plugs. These zinc elements must be inspected every 250 operating hours and replaced when more than half of their mass has eroded. Neglecting these zinc replacements can lead to internal heat exchanger leaks, causing sea water to contaminate the internal fresh water circuit.
Cylinder Liner and Valve Train Lubrication
The overhead valve train and rocker arms require clean, high-grade lubrication to maintain correct valve clearances over long operating periods. Operators should use a certified CD grade 15W-40 marine lubrication oil and change it along with the main lube oil filters every 250 to 500 operating hours, depending on fuel quality and operational loads.
Valve clearances must be checked and adjusted using a feeler gauge during the initial break-in period and every 1,000 hours thereafter. Maintaining proper clearances ensures the intake and exhaust valves seat fully, protecting the valve faces from hot exhaust gas erosion and keeping engine compression high.
Weichai 170 series marine diesel engine, original products from Weichai. This series mainly includes X6170ZC350-1, X6170ZC408-1, X6170ZC450-1, X6170ZC540-1, X6170ZC450-2, X6170ZC480-2, X6170ZC540-2, X6170ZC620-2, X6170ZC650-2, X6170ZC580-3, X6170ZC608-3, X6170ZC680-3, X6170ZC735-3, X6170ZC620-4, X6170ZC620-5, X6170ZC550-5, X6170ZC756-5, X6170ZC818-5, 8170ZC600-1, 8170ZC720-2, 8170ZC818-3, 8170ZC900-3, 8170ZC900-5, 8170ZC1000-5.
Product Frequently Asked Questions
What are the main differences between the X6170ZC756-5 and high-speed electronic common rail engines?
The X6170ZC756-5 relies on a fully mechanical fuel injection pump and a larger 27.24-liter displacement block to produce 756 HP at a low 1500 RPM. High-speed common rail engines generally use much smaller displacements and high injection pressures to produce similar power levels at 2000 RPM or higher. The mechanical Weichai platform offers superior reliability in remote areas because it does not use sensitive electronic sensors or control units that can fail in humid marine environments. Its heavy-duty cast block also delivers a significantly longer overhaul lifespan under continuous heavy loads.
Can this engine operate safely in heavy seas without stalling unexpectedly?
Yes. The engine monitoring system includes a dedicated rough seas operational mode. When a vessel experiences heavy pitching and rolling in high swells, the sudden changes in propeller immersion can cause rapid load fluctuations that might confuse standard electronic governors or trigger automatic safety shutdowns on generic engines. The mechanical governor on this engine dampens these sudden load swings, while the specialized deep oil pan keeps the oil pickup submerged in oil even at high angles of heel. This design ensures continuous lubrication and prevents unexpected engine shutdowns during critical maritime maneuvers.
What marine classification certificates are available for this specific Weichai engine?
The Weichai X6170ZC756-5 engine complies fully with IMO Tier II nitrogen oxide emission standards under Annex VI of the MARPOL convention. Depending on your specific commercial operating requirements, HekoPower can deliver these units with official type-approval and inspection certificates from major global classification registries, including the China Classification Society, Lloyd's Register, Bureau Veritas, and Det Norske Veritas.
How does the single-cylinder head design improve vessel maintenance workflows?
Traditional marine engines often use a single large cylinder head that covers three or all six cylinders. Under that configuration, servicing a single leaking valve or replacing a damaged injector sleeve requires removing the entire heavy cylinder head casting, which usually requires a crane and replaces all cylinder head gaskets. The Weichai 170 series uses individual cylinder heads for each cylinder. This allows a mechanic to isolate and service a single cylinder directly inside a cramped engine room using standard hand tools, saving significant maintenance time and reducing overall repair parts costs.
What type of marine gearbox fits best with this 1500 RPM engine?
The X6170ZC756-5 features a standard SAE 0 flywheel housing that accepts a wide range of heavy-duty commercial marine gearboxes. It pairs exceptionally well with vertically offset transmission units like the Advance HC400 or MB270A series gearboxes. The exact reduction ratio choice depends on whether your vessel requires a high transit speed or maximum towing bollard pull. HekoPower can calculate and supply a fully matched engine, gearbox, and torsional coupling package tailored to your vessel's specific hull design and propeller size.
