Lunn died in Santa Barbara, Calif., on Aug. 5 following a stroke, according to media reports.
A former pilot in the Royal Air Force, Lunn was inducted to the Automotive Hall of Fame in Dearborn, Mich., in 2016.
Lunn oversaw the GT40 project as manager of the Advanced Concepts Group at Ford's Skunk Works, known as Kar-Kraft. The sports car would go on to win the 24 Hours of Le Mans race four consecutive times from 1966 to 1969 and become the first overall winner for Ford Motor Co. — or any American automaker.
The feat helped fulfill a longtime goal of then-Chairman and CEO Henry Ford II.
Here's what Lunn told Hemmings Classic Car earlier this year about the early days of working on the GT40 under then-vice president and general manager Lee Iacocca and targeting Ferrari's dominance:
"We produced the original Ford GT40 — it was called that because the height of the roof was 40 inches, level with my navel — with a 5-liter engine. We decided to make it a mid-engine car for the best weight distribution. But as we were working on it, Iacocca decided that it might be smarter simply to buy Ferrari. He appointed a four-man team to negotiate the purchase--I was one of the four. We went off to Italy and negotiated an agreement. But later the accountants and lawyers got into the picture to thrash out the details. After days of peppering Enzo Ferrari with myriad minor decisions he got so angry he called the whole thing off. Back in Dearborn I said, 'You know, he really did us a favor, because if Ford had purchased Ferrari and continued winning races, everyone would have said it was because of Ferrari's genius. And if they began losing races, the blame would go to Ford for interfering. I said the only real way for Ford to get the entire credit is to do it ourselves. So I was ordered to design, build and race a Ford GT40.'"
In 1962, Lunn also created the first Mustang I concept in just 100 days. It was a two-seat, four-cylinder mid-engine sports car with no roof.
Lunn left Ford in 1971 to become head of engineering for Jeep following the brand's acquisition by American Motors Corp. There, he worked on the XJ Cherokee and Wagoneer and pioneered the use of the unibody chassis for SUVs. He also created the AMC Eagle, the first modern American four-wheel-drive sedan and the precursor to all-wheel-drive crossovers.
After retiring from AMC in 1985, Lunn became vice president of engineering at AM General, where he oversaw the introduction of the Humvee for the Pentagon. In recent years he had been serving as a mentor to mechanical engineering students at the University of California, Santa Barbara, and he was working on developing a "people's car" made entirely out of sustainable materials.
Lunn, who was born in Richmond, England, in 1925 and earned degrees in mechanical and aeronautical engineering at Kingston Technical College, began his career at AC Cars in 1946, according to Automotive News. He later moved to Aston Martin, where he built two DB2s that competed at Le Mans, and British automaker Jowett before joining Ford of England in 1953.
In addition to his engineering accomplishments, Lunn was author of three books: "The Oil Crisis: Sooner Than You Think!," "Globalization: A Worldwide Quest For a Sustainable Future," and "The World Crisis: It All Started With 9/11." He was reportedly working on a fourth book about the environment, sustainability and future cars.
Surviving family members have requested that donations be made in Lunn's name to the UCSB Department of Mechanical Engineering to support undergraduate design projects and laboratories.