But six years after Heat became a twinkle in the eye of several Emap Metro executives - though it is regarded as primarily McIlheney's baby - the MD claims to be losing no sleep over its chances in a big, brutal world. He remains cool in the face of some gloomy predictions following the recent failure of a number of new magazines.
Sitting in his unexpectedly unglamorous office off London's Oxford Street, the big, rough-edged McIlheney - more bloke-down-the-pub than smooth, big-time executive - admits that the market is "tougher than a year ago", but points out that Emap Metro has suffered less than most companies.
His confidence in Heat, however, almost certainly owes much to another factor - McIlheney has had little personal experience of failure. Low- profile he may be, but it is McIlheney who has quietly engineered and presided over some of Emap's greatest successes.
Under his editorship, the pop magazine Smash Hits saw its circulation rocket from 400,000 to 800,000. He went on to launch the highly successful film magazine Empire, and he was MD of Emap Metro when the company acquired FHM, a small-circulation, rag-trade magazine, and transformed it into a new, "laddish" monthly with a circulation of 700,000. Launched to compete with IPC's Loaded, it knocked its rival into a corner. In McIlheney's four years at the helm of Emap Metro, all titles with the exception of Neon, which closed to make way for Heat, have flourished.
All this information is reeled off at breakneck speed by the fast-talking Irishman. "We have done the research and hired some of the best people in town," he says. "I'm quietly confident." He expects Heat, his first hands-on launch since Empire, to have lured 100,000 readers by the summer.
The front covers of all Emap Metro's magazines are displayed proudly above his desk. One of the secrets of their success, he says, is their shared self-deprecating tone. It is a tone that might have come straight from the humorous McIlheney. He started in journalism as a student reviewer for Melody Maker. He jokes that the period is now remembered only for the smack in the mouth he received from Kevin Rowlands of Dexy's Midnight Runners, irate over something he wrote.
He admits that the switch from Melody Maker journalist - music bible of the truly purist - to editor of Emap Metro's teeny-bopping, trashy Smash Hits might have been too great a moral leap for many. "But then I was always a bit poppy," he says wryly: "...to the right of Melody Maker..." What the move showed, of course, was that McIlheney was as interested in the business of magazines as the writing of them.
He plays down his influence on the huge rise in Smash Hits' circulation after he took over. "There was a bit of the luck of the Irish," he says, arguing that Smash Hits' success owed much to the changes taking place in pop music then. But those who watched McIlheney's rise say that it was the first sign of formidable talent, and an all-consuming passion for magazines.
He was 26 when he took over at Smash Hits. That was precocious, but unremarkable given the editors who followed. Mark Frith, who is also involved in the Heat launch, was just 23 when he became the boss at Smash Hits. "You can't appoint a 14- year-old to edit Smash Hits - though the thought has crossed our minds," says McIlheney. "So you need someone who can still remember what 14 was like."
McIlheney believes he was lucky to find a company that nurtures talent - where enthusiasts, not dried-up accountants, invent and shape titles - and the board operates like a "benevolent bank", eager to back good ideas.
At Emap, he says, market research is important, but the idea is the starting-point for a new magazine. "Emap is the kind of company that doesn't care if you are young or old, as long as you are good."
While Emap has a "cradle-to-grave" approach to magazine publishing - with titles targeted at every age group from 10 to 70 - the average age of staff at Emap Metro is terrifyingly young. Does that worry McIlheney, now that he has reached the hideously advanced age of 40? He uses the word "groovy", for instance, but, unlike most of his staff, must remember it from first time round. "It is nice to be here," he says, "for the ironic second take." He warms to the theme. One minute, he says, you are at the staff party strutting your funky stuff; the next, you are the "avuncular figure" being pulled on to the floor by the girls from the typing pool.
But he seems to have no real fear of being put out to grass. McIlheney plans to see Heat established in the market-place, then Emap is moving him to a position of comparable seniority in Paris.
Gone are the days when Emap could offer ambitious staff only the choice of "London, Peterborough or Kettering". In the last five years, it has become an international company, with titles in Australia, France and the US.
So what can we expect from McIlheney in Paris? More acquisitions and launches of the entertainment and male titles that have become his trademark, he says. Will laddishness survive a Channel crossing? He believes that "10 pints and a curry, and hunting in packs" will always be around in Britain, but he is not sure it will translate directly to France. It may be, of course, that Frenchmen are more highly evolved than their British counterparts? That's the trouble with women over 30, says McIlheney: they just don't get laddish irony.
But there will be nothing laddish about Heat, which must win over men and women. McIlheney believes there is a gap in the market for a magazine that covers both music and film. In the late Nineties, he says, specialist knowledge in just one area is judged "anoraky".
The only question now, he says, is: will 100,000 a week go out and buy it? Will it allow McIlheney to board the train for Paris a happy man this summer, or will Heat, as some predict, be his first taste of failure?