Federal-Mogul developments ‘to ramp up engine performance’

New piston, ring and cylinder liner technologies that promise increased performance, reduced emissions and greater durability from heavy-duty diesel engines will be revealed by Federal-Mogul at Germany’s IAA Show in September.

Federal-Mogul is showing what it claims is the world’s first liquid-cooled piston with a sealed-for-life coolant chamber contained in the crown. An integral coolant gallery is created within a steel piston and then filled with a special high-temperature oil and an inert gas, before being sealed for life with a welded plug.

The technology, dubbed EnviroKool by Federal-Mogul, is said to enable higher combustion chamber temperatures to be achieved without compromising durability.

It builds on long-established practice from the 1920s onwards in high-performance petrol engines where sodium-cooled exhaust valves are often used: with applications extending from racing cars and motorcycles and aircraft to the side-valve Bedford Twin-Six engine fitted to the Churchill tank of World War II.

In conventional modern engines, piston crowns are cooled by the lubricating oil, with jets directing it onto the underside of the piston where it spreads into galleries around the inner crown.

Keri Westbrooke, director of engineering & technology at Federal-Mogul Powertrain, said: “The prolonged exposure of engine oil to higher temperatures in the piston oil cooling gallery leads to degradation and carbon build-up, reducing the cooling efficiency and leading to overheating.

“The superior high-temperature properties of the EnviroKool gallery coolant allow it to handle increased gallery temperatures reliably, with the heat subsequently removed from the undercrown – where temperatures are lower – by a standard cooling oil jet.”

With no build-up of carbon in the cooling gallery, heat dissipation remains unhindered for the life of the piston. The new technology is so effective that the oil cooling flow to the spray jets can be cut by 50 percent, says Federal-Mogul, reducing work for the oil pump, lessening parasitic losses and improving engine efficiency.

The heat removed from the piston as a result of the spray jets is additional to that which is conducted away through the pin, piston skirt and rings.

Federal-Mogul Powertrain has already accumulated more than 1,400 hours of testing on heavy-duty engines fitted with EnviroKool Monosteel pistons. Development programs are underway with These engines are expected to offer improved efficiency and reduced emissions without compromising durability.

The company is also developing ultra-high strength and stiffness cylinder liners from a special form of compacted graphite iron which are initially intended for off-highway engines but will make their way into heavy truck engines in due course.

It has also enhanced its Goetze Diamond Coating for piston rings with increased diamond content generating lower friction and greater scuff resistance than previously, enabling engines to run with higher cylinder pressures.