DETROIT -

Not long after its much publicized initial public offering, General Motors revealed just before Thanksgiving that it is doing another multi-million dollar plant investment.

The automaker is planning to use $163.2 million to boost operations in Flint and Bay City, Mich., and Defiance, Ohio. The investment is meant to support engine production for the Chevrolet Volt, Chevrolet Cruze and a new Chevrolet small vehicle to be built in the United States.

Company officials contend the investment will protect 184 jobs at the three sites.

GM calculated the announcement brings new U.S. investments to more than $3.3 billion, creating or retaining more than 8,000 jobs in 21 U.S. plants since emerging from bankruptcy in July 2009.

The OEM offered a deeper breakdown on this most recent investment:

—Flint Engine Operations: $138.3 million and 135 jobs.

—Bay City components: $12.7 million and eight jobs.

—Defiance castings: $12.2 million and 41 jobs.

The manufacturer is looking to increase production of the Ecotec 1.4-liter engine that is used in the Cruze and a 1.4-liter variant used in the Volt. Officials expect the Flint engine facility to start production of 400 engines a day in early 2011 and ramp up to 800 engines a day late next year. The newest investment increases its capacity to 1,200 a day in late 2012.

GM went on to mention Bay City will increase connecting rod and camshaft production and Defiance will boost output of engine block and crankshaft castings.

In less than two years, officials determined they’ve invested nearly $700 million and protected more than 600 jobs at these three facilities.

“This investment is essential in ensuring we can meet the expected high demand for the Chevrolet Volt, Chevrolet Cruze and a small car that will be produced at our Orion Township facility,” explained Kathleen Dilworth, Flint Engine Operations plant manager.

“These three facilities will continue to play a key role in GM’s resurgence and efforts to bring to market vehicles with segment-leading fuel economy,” Dilworth added.

Local union officials also reacted to GM’s latest investment announcement.

“The UAW has and will continue to play a key role in GM’s revival,” stated Terry Everman, UAW Local 599 chairman.

“Our members have demonstrated that they are more than capable of building the latest and greatest in technology that will power some of the most fuel-efficient vehicles in the market,” Everman went on to say.

GM explained the Ecotec 1.4L turbocharged engine for the Cruze is like “two engines in one” with the fuel economy of a small displacement engine and the performance of a larger engine. The engine is designed to help the Cruze Eco achieve a segment-leading EPA-estimated 42 highway mpg.

The company also elaborated about how the 1.4L naturally aspirated engine is meant to enable a range extension for the Volt. After the battery is depleted, the on-board engine-generator can create additional electricity to power the vehicle for hundreds of additional miles.