Engineered Systems Magazine

Engines: Generac

October 29, 2012

GeneracThe new 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:

  • The new Generac 9.0L engine will be used on Generac 80kW and 100kW generators.
  • The new Generac 12.9L engine will be used on Generac 150kW through 300kW generators.

“Gaseous fuels behave very differently than gasoline in a spark-ignited engine, and that means making significant modifications to the engine” said Peter Winnie, director of engineering, Generac. “The fuel system has to be replaced or converted. The valve train must be hardened to withstand wear and higher combustion 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®, a cobalt-based alloy, makes the valve seats especially resistant to corrosion and wear. Valve angles were reduced to minimize the friction that can result from using dry fuel. Hypereutectic cast aluminum pistons were chosen 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 to customers as quickly as possible.

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

Each of the generators using one of the new Generac engines will retain all of its current features and configurable options. Both new engines will also meet all regulatory requirements.