Despite cheap gasoline prices in the U.S., the march to remove weight from light vehicles continues.
Over at Ford, the Shelby GT350R’s new 5.2-liter, V-8 engine is the first Ford engine to be made in-house that uses plasma transferred wire arc process, or PTWA. Ford has used PTWA before, but has outsourced the work.
Ford actually patented the process and licensed it to Nissan, which uses it in the mighty GT-R supercar.
PTWA does away with the heavy (3-mm thick) cast-iron liners in an aluminum engine. Instead, electricity in a plasma cloud vaporizes metal wire, which is then sprayed onto the cylinder walls of the engine block with an air jet. Only the sections of the cylinder walls that the piston rings travel over are treated. The result: Ford saves more than 6 pounds per engine.
That’s huge. Engineers struggle to find every ounce of weight in a car that can be left at the curb.
Now, Ford has installed the expensive plasma equipment at its Essex Engine Plant in Windsor, Ontario, to do the job in-house. So far, only the engine in the Shelby is getting the PTWA treatment. Ford won’t say if the PTWA costs more than pressing in the old-fashioned cylinder liners. But the PTWA process could have more applications in the future, including four-cylinder motors.
“It could benefit any engine,” said Ford spokesman Paul Seredynski. “Bringing it in-house shows our commitment to the technology.”
Ford’s weight-reduction efforts are part of a larger industry trend that is gaining traction.