John K. Evans -- Welsh immigrant, one-time headwaiter and full-time oil promoter -- leans forward, his elbows resting on the cluttered desk in his tiny downtown office, a slight lilt in his voice.

"Believe me, this is a crusade," he says. "Our nation needs what I'm trying to do. It needs energy. It needs a safe, secure source of energy."

At 73, Evans, a millionaire several times over, remains an apostle of oil. His campaign to build a $1 billion oil refinery on the lower reaches of the Chesapeake Bay near downtown Norfolk has angered both regional and national environmental groups -- critics Evans has denounced as "elitist zealots."

But Evans has won critical dredging permits from Army Secretary Clifford L. Alexander Jr., and his financial backing from Cox Enterprises Inc., an Atlanta-based newspaper chain, which has an 80 percent interest in his venture.

Evans says he has already gambled $500,000 of his own money to line up the refinery's crude oil supply and the hundreds of millions of dollars from investors to finance its constrution.

Evans -- Jack, to his friends -- seems to relish the battle. "Most people my age are doddering, for God's sake," he remarks."I don't like golf. So I like to work. . . . I believe in America."

To his opponents, Evans' patriotic talk is mainly misplaced. "He has confused feelings of patriotism," says Joanne Berkley, a leader of a Virginia group called CARE (Citizens Against the Refinery's Effects), which is trying to block the Portsmouth venture. "Most people resent his callous attitude toward our natural resourses and lack of concern for our health . . . He's putting self above the good of the nation."

A self-described maverick, Evans is at once charming and brash, outspoken and modest -- a flamboyant oilman who claims to lead a simple life. "A character, isn't he?" observes Cox Enterprises chairman Garner Anthony. "He's sort of a dying breed of cat."

"He's not out of the mainstream by any means," says Bobby Hall, an American Petroleum Institute official. "He's outspoken, but so are many people in the industry."

Peter A. Bradford, now a Nuclear Regulatory Commission member, described Evans in a book, "Fragile Structures," which dealt with refinery controversies in Maine. "Evans was basically a promoter," Bradford wrote. "His aim was to find a money-making idea, develop it as far as necessary, and sell it, relieving himself of administrative responsibility but retaining a continuing share of the profits."

Despite his flair and wealth, Evans operates from a small, drab back room, overlooking a rear alley and air vents. The front door to the office, at 1707 L St. NW, says "Bowles Secretarial Services." Two letters -- an "o" and a "c" -- are missing. Evans rents his room from the secretarial firm."I use this for my little hideaway," he says. "What the hell do I want a plush office for?"

Lacking the bureaucracy of an oil conglomerate, Evans relies instead on a string of petroleum consultants, engineering firms and lawyers, headquartered from Tulsa to London. They keep him abreast of the volatile oil market and drew up the technical designs for his proposed refinery. "I'll be wheeling and dealing in England," he said last week, shortly before leaving Washington on a trip to London and Honolulu, one of his worldwide journeys in search of oil supplies and financial backers.

From his little D.C. office, Evans, a tall bladish man with a gray mustache, has pressed his fight for the Portsmouth refinery, planned for a 623-acre site on the west bank of the Elizabeth River, a tributary to Hampton Roads. It is designed to handle 175,000 barrels of crude oil daily. hAccording to industry averages, 175,000 barrels of crude could be refined to yield about 3.2 million gallons of leaded and unleaded gasoline along with other products. Evans does not plan to build an average refinery, however. He says a considerable part of its output will likely be jet fuel, probably for the Navy bases nearby. Just what it will produce depends, moreover, on another unknown factor -- the type of crude he can obtain.

Critics, questioning the need for his refinery, have contended that it would cause air pollution, oil spills and endanger oysters, crabs and other marine life in the lower Chesapeake Bay area. "We can build clean refineries," Evans replies, citing a small refinery he helped build in Hawaii.

Evans gained a key victory last December when Army Secretary Alexander approved a permit allowing dredging and other work on the project. "I believe that the refinery and the Chesapeake Bay resources can coexist free of disastrous implications," Alexander said as he overrode vehement objections to the refinery from the Interior Department, Environmental Protection Agency and other government and private organizations.

By his own account, Evans' project is not yet clear. Amid rapidly changing petroleum prospects, he has been trying for several months so far to obtain contracts for crude -- in part, from Venezuela. Not until he has pinned down a crude oil supply, Evans says, can he start looking for additional investors and lenders.

Moreover, lawsuits filed by environmental groups have cast "sort of a cloud on the whole thing," he says. Three suits are pending in federal district and appeals courts in Richmond and the refinery's opponents are expected to file a fourth suit soon.

Despite these obstacles, Evans expresses hope that the Hampton Roads Energy Co., the Washington-based firm set up to build the refinery, can start construction by the end of this year. "It's a good investment, if we can get the damn thing going," he says.

The last major refinery built on the East Coast went on stream in September 1956, according to the National Petroleum Refiners Association. Several small refineries have opened on the East Coast since then -- all of markedly less capacity than the proposed Portsmith venture. One other major East Coast refinery -- a Crown Central Petroleum Corp. project at Wilmington, N.C. -- is currently planned, but it is scheduled to open later than the Portsmouth plant.

As both Evans and Energy Department officials note, East Coast refineries produce only about 25 percent of the petroleum output consumed on the East Coast. The rest is transported from other U.S. refineries or imported from refineries abroad, chiefly in the Caribbean.

"There's no progress in this country. You've got to have progress," says Evans, a man whose unwavering ambition carried him from a humble upbringing to oil riches, some notoriety and entree ianto international circles. "I know the Yamanis of the world," Evans remarks, referring to influential Saudi Arabian Oil Minister Ahmed Zaki Yamani.

Evans spent his childhood in Portmadoc, a Welsh seafaring town. "My family were all sailors," he recalls. His father retired as a ship's captain and later opened a dry goods shop. Orphaned at 10, Evans left school at 14 and went to sea, arriving three years later at Halifax, Nova Scotia, with the equivalent of $24 in his pocket.

He made some money prospecting for gold in Northern Ontario, quickly spent most of it, worked briefly as an actor in Toronto, and then entered the United States -- illegally, he says -- at Buffalo, N.Y. He still refers to himself as a "wetback."

Arriving in New York City, Evans worked as a waiter at a speakeasy during Prohibition, then moved to other jobs as a headwaiter and restaurant captain at the elegant Tuscany Hotel, whose patrons, according to Evans, included O.H. Bond, a vice president for what was then Shell Eastern Petroleum Products Inc. Bond offered Evans a job as a trainee, Evans says, and this bagan a 27-year career with the Royal Dutch Shell Group that took him to Puerto Rico, Brazil, mainland China, New England, New York and Washington.

Evans' years with Shell ended in 1961 after a national controversy. In a political fundraising letter, Evans wrote that he had been asked by then-secretary of the interior Stewart L. Udall to solicit $100 contributions to a Democratic dinner from the oil and gas industry. The letter, which surfaced first in the old Washington Daily News, led to front-page stories by The Washington Post, The New York Times and other newspapers, prompting Republican political charges and considerable Democratic distress. Udall flatly denied asking Evans to write the letter.

"It was very embarrassing to me," Udall, now a Phoenix lawyer, recalled recently. "Jack and I never saw each other after then (except on rare occasions). I learned my lesson . . . It was better to just keep everybody at arm's length."

Nevertheless, Udall regards Evans as a relatively enlightened oilman. "I still have a soft spot for Jack, despite what he did to me," Udall remarked.

The incident changed Evans' career. Rather than be transferred from Washington, "I took early retirement," he says. "I wanted to go on my own and I bolted. I probably would never have the gumption to do it if that hadn't happened."

His first venture was the Independent Fuel Oil Markerters Of America, a group formed, according to its Aug. 1, 1961, press release, to combat "onerous government regulations which discriminate particularly against small business concerns." Evans, the group's executive director, claimed success after a five-year campaign to gain relaxed federal import controls on industrial fuel oil.

Meanwhile, Evans also worked as an oil trader and started promoting refineries. His first and so far only successful refinery venture was in Hawaii, a 67,900-barrel-a-day operation that went on stream in 1972. It is Evans' largest known financial holding. His 6.2 percent interest in Pacific Resources Inc., the parent company, is currently valued at more than $12.6 million.

The Hawaiian refinery also brought Evans and Cox chairman Anthony together for the first time. According to both men, Anthony, who lives in Hawaii, got to know Evans after investing in the refinery there. Evans told Anthony about his planned Portsmouth venture and Cox later acquired its interest in the project.

Evans' refinery plans proved failures at several East Coast sites, including Machiasport, Maine, and Savannah, Ga. He turned over his Machiasport venture to Occidental Petroleum Corp. in the late 1960s, and Occidental eventually dropped the project amid oil import restrictions and environmental controversy.

Evans appears a bit miffed that another oil group, operating as Southland Refining Co., is currently moving ahead with plans for a $260 million, 50,000-barrel-a-day refinery at Savannah, where his own project met defeat. "I didn't have the muscle to be able to go ahead with it," he recalls. "The whole thing is ridiculous."

Evans, a retired Air Force Reserve colonel who has been married four times, does not confine his outspokenness to the oil business. He is also an inveterate writer of letters to the editor of The Washington Post and other newspapers, having managed to get 36 letters printed by The Post in the past 18 years. His most recent such letter, published in May, criticized the District of Columbia public shools, which he says all five of his children have attended, at least for a time.

"I believe, having come up the hard way, that the child with motivation and guts will survive and prosper in even the District schools, but this means that those not born wise are condemned to economic slavery all their lives," he wrote.

Why write such letters?"I must have a knack," he replies. "I'll see something. I'll get mad, rattle it off and forget about it."