Glen W. Bell Jr., whose idea in 1951 to sell crispy-shell tacos from the window of his hamburger stand became the foundation of Taco Bell, the restaurant chain that turned Mexican fare into fast food for millions of Americans, died at his home in Rancho Santa Fe, Calif. He was 86

His death was announced Sunday on the Taco Bell Web site. No other details were provided.

Mr. Bell never forgot the first taco buyer at Bell’s Hamburgers and Hot Dogs in San Bernardino, Calif., one of three stands he owned at the time.

“He was dressed in a suit and as he bit into the taco the juice ran down his sleeve and dripped on his tie,” Mr. Bell recalled in “Taco Titan: The Glen Bell Story,” (Bookworld Services, 1999), a biography by Debra Lee Baldwin. “I thought, ‘Uh-oh, we’ve lost this one.’ But he came back, amazingly enough, and said, ‘That was good. Gimme another.’ ”

By the time Mr. Bell sold the chain to PepsiCo in 1978, it had grown to 868 restaurants. Today, the company says, more than two billion tacos and a billion burritos are sold each year at more than 5,600 Taco Bell restaurants in the United States and around the world.

Drive-in stands dotted San Bernardino when Mr. Bell opened his first one there in the late 1940s. One competitor, only a few miles away, was the original stand opened by two brothers with the last name of McDonald.

They all were capitalizing on the emerging Southern California car culture, offering prompt service and streamlined menus of mostly standard fare like hamburgers, hot dogs, French fries and milk shakes.

But Mr. Bell, a fan of Mexican food, had a hunch that ground beef, chopped lettuce, shredded cheese and chili sauce served in the right wrap could give burgers a run for the money. The problem was which wrap. Tacos served in Mexican restaurants at the time were made with soft tortillas.

“If you wanted a dozen, you were in for a wait,” Mr. Bell said. “They stuffed them first, quickly fried them and stuck them together with a toothpick.”

The solution: preformed fried shells that would then be stuffed. Mr. Bell asked a man who made chicken coops to fashion a frying contraption made of wire.

Tacos became a hit at Bell’s, selling for 19 cents each. They were such a hit that by 1954 Mr. Bell and a partner opened Taco Tia, his first restaurant selling only Mexican-style food.

Two years and three Taco Tias later, Mr. Bell sold his interest after his business partner resisted expanding any further. Mr. Bell then opened another fast-food Mexican restaurant in Pasadena, in 1957, and a year later took on three partners in a chain called El Taco.

After four El Tacos, Mr. Bell decided he no longer wanted to answer to any partners. He sold out again. Then, in 1962, with a $4,000 investment, he opened the first Taco Bell, in Downey, Calif. Over the next two years, he started eight more Taco Bells, each with a grand opening featuring live salsa music, searchlights and free sombreros. The first of its franchises opened in Torrance, Calif., in 1965.

PepsiCo greatly expanded the chain after purchasing it in 1978 for about $125 million, then spun it off to Tricon Global Restaurants in 1997. Tricon changed its name to Yum Brands in 2002.

Glen W. Bell Jr. was born in Lynwood, Calif., on Sept. 3, 1923, one of six children of Glen and Ruth Johnson Bell. When he was 12, the family moved to a small farm outside of San Bernardino.

At 16, with the family facing hard times, according to his biography, Glen Jr. “goes on the bum” and “rides the rails in search of work.” He joined the Marines in 1943 and served in the Pacific.

Back in San Bernardino after the war, Mr. Bell bought a surplus Army truck and began hauling adobe bricks at 5 cents each. A miniature golf course that he leased failed to make a profit. Then, he opened a hamburger stand in a Hispanic neighborhood.

Mr. Bell married Dorothy Taylor in 1947. They were divorced in 1953. He is survived by his wife of 54 years, Martha; three sisters, Delores, Dorothy and Maureen; a daughter, Kathleen; two sons, Gary and Rex; and four grandchildren.

The trade publication Nation’s Restaurant News has credited Mr. Bell with introducing millions of Americans to Mexican-style food. “I always smile,” Mr. Bell told the magazine in 2008, “when I hear people say that they never had a taco until Taco Bell came to town.”

Glen William Bell jr