Home > Resources and Tools > Engineer Resources > PowerConnect Newsletter > June 2013 > New Generac Spark-Ignited Engines Mean Longer Life, Shorter Lead Times
New Generac Spark-Ignited Engines Mean Longer Life, Shorter Lead Times

New Generac Spark-Ignited Engines Mean Longer Life, Shorter Lead Times


The popularity of gaseous fuel in commercial and industrial power applications continues to grow. Applying natural gas and LP-fueled engines to generators, however, requires considerable engineering skill to ensure reliability and long life. With more than 20 years of in-house engine design expertise, Generac Power Systems has designed and manufactured two new gaseous-fueled engines specifically for use in several Generac industrial power systems. Generac’s 80kW and 100kW generators now feature the new Generac 9.0L Engine, with the Generac 150kW through 275kW generators now powered by the new Generac 12.9L Engine.

Gaseous fuels behave very differently than gasoline in a sparkignited engine, and that means making significant modifications to the engine,” says Peter Winnie, director of engineering at Generac. “The fuel system has to be replaced or converted. The valve train must be hardened to withstand wear and higher temperatures. Engine timing needs to be addressed. By designing and building our own engines, we can ensure that every challenge is met and that every generator meets the high standards of reliability our customers expect, especially in mission-critical applications.”

In manufacturing its new engines, Generac used stainless steel for the intake and exhaust valves to ensure durability and long life. Stellite®, an extraordinarily tough cobalt-chromium alloy, makes the valve seats resistant to corrosion and wear. As dry-fuel engines lack the benefit of the lubricating qualities of liquid fuels, Generac reduced the valve angles from 45 to 30%, thereby minimizing the added friction that results from using gaseous fuels. The pistons are made of hypereutectic, cast aluminum to resist thermal expansion for tighter clearances that result in quieter operation and longer piston-ring life.

Manufacturing its own engines also helps Generac ensure that it can deliver products with the shortest lead-times in the industry.

“Generac prides itself on short manufacturing lead-times,” says Paul Bowers, Generac Industrial Power’s vice president of sales. “One way we achieve this is through vertical integration. Manufacturing these new 9.0L and 12.9L engines ourselves gives us additional control over our products and allows us to meet our customer’s demands more effectively.

Each of the generators using one of the new Generac engines will retain all of its current features and configurable options, and will ship from the factory in full compliance with all regulatory requirements.

And like all of the company’s industrial generators, it is fully compliant with IBC 2009 and 2012 seismic standards.