Reviving the Mustang 345 with the 1.6L Ford Kent Engine

[MikePhua]

Origins of the Mustang 345 and OMC’s Compact Equipment Legacy
The Mustang 345 skid steer loader emerged in the early 1980s as part of Owatonna Manufacturing Company’s (OMC) push into compact construction equipment. OMC, founded in Minnesota in 1883, had a long history in agricultural and industrial machinery before entering the skid steer market in the 1960s. The Mustang brand became synonymous with rugged, affordable machines for small contractors and property owners. By the time the 345 model was introduced, OMC had refined its designs to emphasize simplicity, reliability, and ease of maintenance.
The 345 was powered by the 1.6L Ford Kent crossflow engine—a compact inline-four petrol engine originally developed in the UK in the 1960s. Known for its use in Ford Escorts and Formula Ford race cars, the Kent engine was prized for its straightforward design and tunability. In industrial applications like the Mustang 345, it offered a balance of torque and fuel efficiency, ideal for light-duty excavation, grading, and material handling.
Sales figures for the Mustang 345 were modest but steady, with thousands of units sold across North America. Its popularity stemmed from its affordability and the widespread availability of Ford engine parts, making it a favorite among rural users and small-scale contractors.
Diagnosing a Short-Run Engine Issue
A common issue with aging skid steers like the Mustang 345 is short-run engine failure—where the engine starts easily but dies after 30 to 60 seconds. This symptom often points to fuel delivery problems. In this case, the machine had sat unused for over a decade, and the original carburetor had seized due to corrosion in the throttle shaft and plate.
The temporary fix involved installing a forklift carburetor using a fabricated steel adapter. While functional, this setup lacked precision in fuel metering, leading to rich mixtures and fouled spark plugs. The engine’s behavior—running longer after sitting—suggested debris in the needle and seat, possibly restricting fuel flow after initial startup.
Fuel System Restoration and Component Sourcing
To restore proper function, the fuel system must be addressed holistically:

• Inspect and clean the fuel tank, pickup tube, and check valve.
  
• Test the mechanical fuel pump for consistent output pressure (typically 3–5 psi for carbureted systems).
  
• Replace or rebuild the carburetor with a compatible unit.
  

The original Zenith Model 33 carburetor is ideal but expensive. Alternatives include:

• Weber 34 ICH: A universal single-barrel carburetor pre-jetted for 1.5–1.6L engines.
  
• Autolite/Motorcraft units from 1970s Ford Pintos: More affordable but require tuning.
  

A gravity feed test confirmed the fuel pump’s inadequacy, reinforcing the need for a rebuild or replacement. The governor—responsible for regulating engine speed under load—had failed years earlier. A used governor from a six-cylinder Ford engine was sourced, with plans to adapt its linkage and rebuild it using a compatible kit.
Ignition System Modernization
The original ignition system used a points-and-condenser setup, typical of pre-electronic engines. While functional, these systems degrade over time and require frequent adjustment. Upgrading to electronic ignition improves reliability and spark consistency.
Options include:

• PerTronix Ignitor: A drop-in electronic conversion for many Ford distributors, though some models lack vacuum advance.
  
• Hot Spark kits: Affordable and compatible with Lucas, Bosch, and Motorcraft distributors.
  

Identifying the distributor type is crucial before ordering. Removing the unit and checking casting numbers ensures compatibility. Electronic ignition also reduces maintenance and improves cold starts—especially valuable in seasonal equipment.
Restoring Factory Configuration and Aesthetic Integrity
Beyond mechanical function, restoring the Mustang 345 to its original configuration enhances resale value and operational confidence. Missing components included:

• Air horn: The elbow-shaped intake piece atop the carburetor.
  
• Intake hose: Connects the carb to the engine’s intake manifold.
  
• Engine cover: Protects the gas engine from debris and weather.
  
• Governor: A backup unit is desirable in case the rebuilt one fails.
  

These parts are increasingly rare, as many machines have been repowered or scrapped. Salvage yards, online marketplaces, and vintage equipment forums are the best sources. Networking with restorers and collectors often yields leads on obscure components.
The Ford Kent Engine’s Industrial Legacy
The 1.6L Kent engine, despite its automotive origins, found a second life in industrial and agricultural equipment. Its crossflow head design improved breathing efficiency, and its cast-iron block offered durability. In Formula Ford racing, it became a benchmark for reliability and tunability. In skid steers, it provided enough torque for hydraulic systems without excessive fuel consumption.
Key specs include:

• Displacement: 1.6 liters (97.5 cubic inches)
  
• Bore x Stroke: 81mm x 76.95mm
  
• Compression Ratio: ~9.0:1 (varied by application)
  
• Power Output: ~70–80 hp in industrial trim
  
• Carburetion: Typically Zenith or Weber single-barrel units
  

Its simplicity made it ideal for field repairs, and its widespread use ensured parts availability long after production ceased.
Hydraulic System Observations and Operational Viability
Initial tests showed strong hydraulic performance, indicating that the pump, valves, and cylinders were in good condition. This is critical, as hydraulic repairs can be costly and time-consuming. With a properly functioning fuel system and ignition, the Mustang 345 could be fully operational.
Recommended steps before regular use:

• Full fluid change: Engine oil, hydraulic fluid, coolant.
  
• Filter replacement: Fuel, oil, hydraulic.
  
• Belt and hose inspection: Replace any cracked or brittle components.
  
• Grease all fittings: Ensure smooth articulation and reduce wear.
  

Anecdotes from the Field and Lessons Learned
One technician recalled a similar restoration of a 1982 Mustang 345 used on a cranberry farm in Wisconsin. After sitting idle for 12 years, the machine was revived with a rebuilt Kent engine and a Weber carburetor. It returned to service hauling brush and grading trails, a testament to the durability of these compact loaders.
Another story involved a contractor who retrofitted a Mustang 345 with a Honda GX630 V-twin engine after failing to source Kent parts. While functional, the conversion required custom mounts and hydraulic recalibration—highlighting the value of original components when possible.
Conclusion and Recommendations
Restoring a vintage Mustang 345 with its original Ford Kent engine is both a technical challenge and a tribute to industrial heritage. Success depends on methodical diagnostics, sourcing compatible parts, and respecting the machine’s design intent. While repowering is an option, preserving the original configuration offers historical value and mechanical satisfaction.
For owners undertaking similar projects:

• Document all part numbers and configurations.
  
• Network with vintage equipment communities.
  
• Prioritize fuel and ignition system integrity.
  
• Consider electronic upgrades for reliability.
  
• Maintain hydraulic cleanliness and lubrication.
  

The Mustang 345 remains a symbol of American ingenuity in compact equipment. With care and persistence, these machines can continue serving for decades beyond their intended lifespan.