United Engine & Machine is re-introducing the DUALOY brand for light/medium diesels in early 2018 which are aimed squarely at the direct-replacement market.

“These pistons are available for Cummins, Power Stroke, and Duramax applications. In addition to the stock replacement pistons, there will be some versions which will be destroked for engine rebuilders to allow for decking of the block,” said UEM Sales and Technical representative, Marko Glush. “Pistons which require cooling channels in the pistons do have those.”

The Dualoy brand was actually started over half a century ago by United Engine, who was heavy into the diesel market at that time. In fact, in the early 1950s, the company was the first to develop the method for manufacturing iron-insert cast pistons.

“It’s a very difficult process to do,” says Glush. “There’s an increased chance for porosity in there, and it takes special casting equipment to do this.”

“The top ring land has an iron insert in the casting, which keeps the top ring from beating itself to death against the aluminum. These use a Keystone ring on the top land.”

Recently they increased their plant capacity and mold capacity to be able to return to their roots and build iron-insert style pistons required by diesel engines again.

There will be twelve applications released initially with more to come after these are available. The company also offers pistons for the early Ford non-turbo diesel and Oldsmobile diesel applications, among others.