June 27, 2007 — Navistar's International Truck and Engine Corp. has chosen Brazilian metalcaster Tupy S.A. to supply compacted-graphite iron engine blocks for two large-bore diesel engine products, the MaxxForce 11 and MaxxForce 13. The blocks will be cast at Tupy's foundry at Mau, in S©o Paulo, beginning later this year.
Tupy uses the Sintercast process control technology for CGI casting, a product of Sweden's Sintercast AB. The plant is already producing heavy-duty diesel engines with CGI for the German truck group MAN AG.
Compacted-graphite iron is created by adding magnesium to molten gray iron. The process requires careful process control, but the resulting material is said to offer advantages over gray iron, including a higher fatigue limit because CGI's molecular structure is fracture-resistant.
"The MaxxForce 11 and MaxxForce 13 will be the first heavy-duty diesel engines in North America to leverage advances in manufacturing technology to offer an engine block cast from CG Iron," stated Jacob Thomas, Navistar vice president Jacob Thomas. "The use of this material allows us to provide a high-strength block without added weight — a valuable attribute for our truck customers."
Tupy's cast blocks will be machined by Navistar's MWM International Motores at Santo Amaro, Brazil, and shipped to Navistar's new engine plant in Huntsville, AL, for final manufacturing, beginning in 2008. Navistar is building a new operation near its existing Huntsville plant, but the initial products in the MaxxForce series will be partially assembled in Germany and "trimmed" at Huntsville.
"Our ability to source globally and utilize MWM International for the machining of this new innovative block design demonstrates our commitment to integration and growth as a global company," stated Persio Lisboa, International Engine Group v.p.-purchasing and logistics. "This also allows us the opportunity to leverage our assets to serve the North American market, while creating a competitive advantage for our MaxxForce big bore engines."
The MaxxForce engines are said to offer excellent fuel economy and power characteristics, low noise vibration and harshness, and high strength, with low overall weight. The engines will be installed in International's ProStar line-haul tractors, TranStar regional-haul tractors, and WorkStar severe-service vehicles in the U.S. and Canada.