3.0 Duratec Forged Pistons – High Compression
PLEASE STATE BORE SIZE AND COMPRESSION RATIO WHEN ORDERING. THESE ARE CUSTOM MADE TO ORDER.
Full sets of Ford 3.0 Duratec Forged Pistons – High Compression – are available from Torque Developments International, in various bore sizes and compression ratios. These pistons have been proven to perform well and be reliable under endurance racing conditions for many years.
- Aligned Grain Flow Technology*
- Xylan coating**
- Includes rings, pins and clips
* AFT is about making the best use of the grains of metal within the piston. A forged piston is already stronger than a cast one. The cast piston has larger grains that are more three-dimensional in shape, but the source material for the forged piston – a long aluminum extrusion that’s cut off into piston-size slices – means that those grains have already been worked into a longer, thinner form, which helps to prevent crack propagation.
JE’s idea was to make even better use of the inherent advantages of forging and optimize crack resistance in highly stressed areas, such as where the pin tower meets the crown.
“There were additional manufacturing steps that we had to take to ensure that the grain structure was in the proper locations,” says Cody Mayer, JE Piston’s Senior Manager of Advanced Product Development. “We further work those grains to stretch them and form them around the contours of the piston forging shape. Longer, thinner grains that are compressed more tightly together create additional grain boundaries in the most critical areas.”
In a piston, the grain boundaries in the metal provide resistance to cracks. Think of it as chopping a log: it’s much harder to cut across the grain, with each wood-cell fiber providing resistance to the axe. But if you slit the log from the top, it’ll crack much more easily along the grain.
“When a crack propagates through the material, it rarely happens all at once, especially in a fatigue situation in a reciprocating engine part that’s experiencing millions of load cycles,” says Mayer. “The crack starts very small and grows over thousands of cycles. But the elongated grains, packed tightly together, form walls to prevent the crack from progressing. The crack stops every time it hits a grain boundary. It’s much more difficult for it to propagate far enough through the piece to cause a failure.”
** A dry-film lubricant applied to the piston skirt, Xylan helps reduce friction to not only improve performance but also quiet down the piston in the cylinder bore. The coating is permanent, as it’s applied with a unique computer-controlled screen-printing process that’s designed not to compromise the piston’s base material, geometry or heat treatment.
The piston is fully machined to the designated outside diameter before the coating is applied in house. The exact depth of the coating is kept proprietary, but it does conform to the detailed skirt shape and profile that is specific to each application.
Dry-film lubricants have been around since liquid-free lubricants were needed for the space race. There are a number of different formulas but most of the automotive coatings are based around a chemical called molybdenum disulfide—which often referred to in the performance industry simply as “moly.”
How does moly work? It’s a very structured, hexagonal-shaped molecule that exhibits strength when tipped on its ends, but when lying on its side moly will shear apart easily. Think of trying to slide across a rough concrete floor with sneakers on your feet. You won’t go too far. Now spread thousands glossy postcards across the floor and try again. There is no liquid oil or lubricant, however, the low shear properties between the slick cards allow plenty of sliding between the different layers. The overall effect is low friction as you glide across the floor with very little effort.
For info on our full range of services please go to http://www.tdi-plc.com