Subaru’s new ER12 rammer engine features a carefully balanced and engineered design, and is exclusively intended for the demanding application of rammers. With specially-designed components and overhead cam (OHC) technology, this 3-hp., 4-stroke engine is lightweight, yet rugged and powerful. Weighing in at slightly more than 20 pounds, the ER12 offers more power and up to 24-percent more output than similar competitive engines, all while being lighter weight and designed for optimized balance and performance.
Unlike existing competitive rammer engines that have been modified from their general-purpose engines, Subaru’s ER12 rammer engine is specifically designed for this piece of equipment and its unique demands. The vertical cylinder design is slim and compact, and maintains an excellent center of gravity to effectively transmit power to the ground, resulting in superior performance. The recoil has been integrated into the flywheel and blower housing, further enhancing balance and overall engine performance.
Utilizing belt-driven OHC technology, the ER12 offers more power, easier starting and quieter operation than competitive engines in its class. The OHC design provides improved engine performance without adding extra weight, while the technology allows the intake and exhaust valves to be positioned to offer lower resistance for the air/fuel mixture flow, thus optimizing engine performance. The ER12 also features a highly efficient hemispherical combustion chamber. By centrally locating the spark plug, maximum combustion is achieved and the engine is able to utilize a higher compression ratio, resulting in more power and torque.
The ER12’s lightweight design further optimizes rammer balance, and the reduction in weight is achieved with the inclusion of several specially-designed features. The crankcase features a thin-wall, yet durable construction and a lightweight aluminum flywheel. High-strength torsion bolts extend from both the cylinder head and the gear cover deep into the crankcase. This unique design allows less material to be required on the cylinder, heads and blocks, further reducing overall weight while improving structural strength. The muffler size and weight has been reduced, thanks to the use of high-strength aluminized metal, while the resin air cleaner features glass-fill, making it lightweight, durable and resistant to cracking.
Because of their constant up-and-down motion, rammer engines are difficult to lubricate. The ER12 has addressed this concern by including a pressure lubrication system. A gear pump transfers oil from the bottom of the crankcase to various parts of the engine that need critical lubrication. Additionally, the belt moves oil to the top of the engine, ensuring all areas are properly lubricated. This thorough lubrication leads to better performance and longer engine life.
Engine performance is further optimized thanks to the uniquely designed breather system. This system separates the oil in the crankcase from air passing through the breather system. Not only does this result in better performance, oil consumption rates and emissions are reduced.
To enhance equipment and operator safety, the ER12 also includes a low oil pressure shut-off system, while an emergency-stop device further increases safety. A digital CPU ignition system is designed to protect the operator and engine from over-speed, while also providing more accurate spark timing.
Maintenance is simplified with a structurally-integrated crankcase and improved air cleaner sealing. For added convenience and transport ease, the ER12 can be laid on either side without causing oil or starting problems.
The 120-cc displacement ER12 engine offers an output of 2.6 kW (3,600 rpm) and is suitable for 60- to 80-kilogram class rammers. It meets EPA Phase 3 emissions standards and is backed by Subaru’s 3-year limited warranty.
Subaru Industrial Power Products/(847) 540-7300