Honda’s largest vehicle engine plant in the world in Anna, Ohio, has built its 15 millionth engine since opening in 1985.

As the milestone engine was finished, a $US75m expansion project at the plant continued toward completion later this year. The project will transfer connecting rod and camshaft production from Japan to Ohio.

The 15 millionth engine, produced on line two, is a V6 destined for an Accord coupe to be assembled 45 miles to the east at the Marysville Auto Plant.

The Anna engine plant has three assembly lines and two foundries, one for aluminium and one for ferrous casting. The plant produces drive shafts, connecting rods, brake components and other parts, as well as all of its own engine blocks and heads.

The Anna facility will serve as the engine supply source for the latest Honda Manufacturing of Indiana plant under construction in Greensburg, Indiana. Production there begins in autumn 2008.

Marysville will later this year celebrate 25 years of car production in America – starting with an ’82 Accord – and the anniversary coincides with the production of the redesigned ’08 model.

The Anna engine plant reached its milestone 22 years after opening. At its current production rate – 1.15 million engines annually – it will take only 13 years to build another 15 million engines.

Its engines power a variety of Honda and Acura models made in Ohio and in two plants in Alliston, Ontario, Canada.

The Anna plant has been expanded many times, with the current project transferring additional connecting rod and crankshaft business from Japan. Investment in the plant now exceeds $US1.4bn.