Description

Woodward 8280-4001: Fuel Injection Pump Assembly for Medium-Speed Diesel Engines

Mechanically Governed, In-Line Fuel Pump for Industrial Generator Sets

The Woodward 8280-4001 is a high-precision, camshaft-driven, in-line fuel injection pump assembly designed for medium-speed industrial diesel engines. It is a complete, factory-calibrated unit that meters and delivers high-pressure fuel to the engine’s cylinders, featuring an integral mechanical-hydraulic governor for speed control. This specific part number denotes a configuration engineered for a particular engine model and application, typically in the 500-2000 kW range for standby or prime power generation.

Product Overview

This assembly is the heart of the engine’s fuel system. It combines a multi-plunger injection pump with a self-contained governor, timing advance mechanism, and fuel rack actuator into a single, serviceable unit. The 8280-4001 is designed as a direct replacement or OEM component for specific medium-speed diesel engines from manufacturers like MTU, Caterpillar, Wärtsilä, or MAN, ensuring precise fuel delivery and stable engine speed regulation under all load conditions.

Core Features & Benefits

Integral Mechanical-Hydraulic Governor: The built-in governor provides isochronous (zero speed droop) or droop speed control, maintaining constant engine RPM (and thus generator frequency) despite load changes. It responds rapidly via flyweights and hydraulic servos to adjust the fuel rack.
Positive Displacement Plunger Design: Utilizes individual cam-actuated plungers and barrels for each engine cylinder to generate the extreme pressure (typically 15,000 – 20,000+ psi / 1000 – 1400+ bar) required for direct injection, ensuring consistent fuel quantity per stroke to each cylinder.
Automatic Timing Advance: Most configurations include a centrifugal timing advance device that optimizes injection timing based on engine speed. This improves cold starting, reduces smoke, and enhances fuel efficiency across the operating range.
Factory Engine-Calibrated: Each 8280-4001 is calibrated on a test bench for a specific engine model, horsepower, and speed rating. This plug-and-play compatibility guarantees optimal performance, emissions, and reliability when used as specified.
Heavy-Duty Construction: Manufactured from hardened and ground steel alloys for the camshaft, plungers, and rollers to withstand high internal pressures and provide long service life in continuous duty applications.
Simplified Installation: Supplied as a pre-assembled unit with matched internal components, reducing commissioning time and potential for error compared to setting individual pump elements.

8280-423

Technical Specifications (Application Specific)

Parameter	Specification / Description
Manufacturer Part Number	Woodward 8280-4001
Pump Type	In-line, Plunger-type, with Integral Governor
Governor Type	Mechanical-Hydraulic (Isochronous or Droop)
Number of Pumping Elements	Matches engine cylinder count (common: 6, 8, 12, 16, 20).
Rotation Direction	Specific to engine (as viewed from drive end). Must match engine.
Fuel Delivery Calibration	Precisely set for the engine’s rated horsepower and full-load fuel consumption.
Operating Pressure	Capable of generating injection pressures exceeding 1000 bar.
Drive Connection	Splined or keyed shaft, specific to the engine’s gear train.
Mounting Flange	Machined to match the engine block interface of the specified model.
Application	Medium-speed diesel engines (e.g., 720-1800 RPM) for generator sets.

System Context & Critical Information

WARNING – APPLICATION SPECIFIC: The Woodward 8280-4001 is NOT a universal pump. It is engineered, calibrated, and balanced for one specific engine model, horsepower, and sometimes a specific ambient condition rating.

Essential Data for Procurement/Replacement:
1. Engine Manufacturer, Model, and Serial Number.
2. Engine Full Load Rating: kW/HP and RPM.
3. Application: Prime Power, Standby, Marine.
4. Original Pump Identification: Tag number from the old pump.
Failure to provide this information risks severe engine damage due to incorrect fuel delivery (over-fueling causing overheating/detonation, or under-fueling causing power loss).

Installation, Timing & Service Warnings

Qualified Personnel Only: Installation, timing, and calibration require training on diesel fuel systems. Do not attempt internal adjustments.
Precision Timing is Mandatory: The pump must be timed to the engine with a dial indicator to a specific lift at Top Dead Center (TDC) per the engine service manual. Incorrect timing destroys performance and can cause piston/valve contact.
Cleanliness is Paramount: The unit must be kept spotlessly clean. The fuel supply system (tank, lines, filters) must be meticulously clean and purged. Contamination will destroy the precision components.
No End-User Adjustment: The maximum fuel stop, governor springs, and rack limits are factory-set. Tampering with these will alter the engine’s air-fuel ratio, leading to excessive smoke, overheating, catastrophic failure, or voiding emissions certifications.

Typical Applications

Emergency Standby Generators: For hospitals, data centers, water treatment plants, and telecommunications hubs.
Prime Power Generation: In remote mining, industrial plants, and island communities.
Marine Auxiliary Power: Generator sets on workboats, ferries, and commercial vessels.
Legacy Engine Support: A critical service part for maintaining older, mechanically controlled industrial engines.