Subaru’s All-Season Engine combines the powerful benefits of overhead cam (OHC) technology from its EX Series engines with special cold-weather features of the SX Snow Series line to create a multi-seasonal solution for a variety of outdoor equipment.
Initially developed as a year-round power solution for rotary brooms, Subaru’s All-Season Engine doesn’t require any adjustments to accommodate varying weather conditions. The 9-horsepower unit is designed to operate in temperatures ranging from 20 degrees below zero (Fahrenheit) up to 140 degrees. It is suitable for additional types of multi-season equipment including log splitters, chippers and shredders, and lawn and turf seeders.
The All-Season engine features chain-driven OHC technology, a standard for high-performance automotive engines. The technology allows the intake and exhaust valves to be positioned for optimum engine performance, and offers lower resistance for the air/fuel mixture flow. Designed with a highly efficient pent-roof-type combustion chamber, the All-Season Engine is able to uses a high compression ratio, producing higher power and torque while limiting exhaust emissions and fuel consumption.
To have the ability to function in a variety of temperatures and weather conditions, an engine must provide the proper balance of cooling and heating. The All-Season Engine achieves this thanks to the inclusion of several extreme weather features. To combat excessive heat in warmer temperatures, the engine is designed with patent-pending technology and other special features to provide outstanding cooling. To use every possible cooling area, special heat dissipation fins have been built into the mounting base, cylinder and both the inner and outer crankcase surfaces. The OHC technology allows for 360-degree airflow around both the exhaust and intake valve stem areas to provide additional cooling action.
An anti-icing baffle is included to ensure proper operation in cooler temperatures and humid conditions. This feature redirects heat from the cylinder head back to the carburetor to keep it warm and prevent problems commonly associated with cold-weather operation. Humid environments can result in moisture build up and potential freezing in the engine. The anti-icing baffle also directs heat into the air cleaner system, eliminating potential ice build-up and airflow restriction in the nearby venturi area. Additionally, the transfer of warm air to the carburetor helps to maintain engine temperature, keeping the engine warm for easy starting on the first pull – every time.
Easy, one-pull starting is further encouraged with the inclusion of an automatic decompression system and specially designed recoil housing. The automatic decompression system reduces the required recoil pulling force by 30- to 40-percent when compared with competitive models. With fewer moving parts and an optimized-capacity rigid muffler, the All-Season Engine operates a full 2dBA (decibel level) quieter than other same-class engines.
For further protection in cold-weather environments, the All-Season Engine includes anti-icing guards. These strategically placed guards prevent snow and ice from entering the engine and freezing up, causing damage to the governor system, vital controls and linkages.
To avoid common problems associated with battery-starters in cold weather, the All-Season Engine is available with an optional 120-volt starter system. It meets EPA and CARB emission regulations, and is backed by an industry-leading 3-year limited warranty.