McIlroy (25) won the Speight's Invitation singles in 2006 and 2008 and would like to claim a third title to equal the feat of the great Rowan Brassey (Auckland).
The four-day event starts this afternoon. McIlroy is the TAB favourite and will pay $5 if he wins.
"I have played some serious bowls in Adelaide and my form's pretty good," he said. "It would be great to equal Rowan Brassey and get another caricature of myself on the club wall."
McIlroy has won his title in even years and the odds must be in his favour in 2012.
The highlight of McIlroy's career was to win his first national title in 2007.
"All the great players in the game talk about their first national title," he said. "It was very exciting to win at the age of 20. It was the turning point in my career."
McIlroy was unlucky to miss selection for World Bowls in 2008.
"I'd played the Asia and Pacific champs in 2007 and thought I had a reasonable chance," he said. "But that side in 2008 was strong and won a lot of medals and the Leonard Trophy for the first time."
McIlroy was in the wilderness for two years but came back into the Black Jacks squad last year.
"Once you are left out of the top side in a sport you're passionate about it makes you more determined to get back in," he said.
McIlroy knew he had to be successful on the domestic scene and in overseas events to change the selectors' minds.
"It's good to be back in and I'm happy to play in World Bowls," he said. "I'm very excited. It's the pinnacle event for bowls."
McIlroy is in the hot seat as the singles player and is lead in the pairs for Richard Girvan.
"I'm obviously a bit nervous but at the same time I'm very excited. The number of world-class players in the singles is mind-boggling," he said. "I've got to play to my absolute best to have a chance of winning a medal."
McIlroy is having a thorough preparation for the championships by playing club bowls for the Ascott Park Club in Adelaide for seven weeks.
"It allows me to get used to the environment and the green conditions," he said. "I'm hoping it might give me an edge."
The greens being used for World Bowls get a lot of wind and McIlroy is getting the experience to adjust to it.
"It could be a good thing for us," he said. "It is not unusual to have wind in New Zealand. A lot of the other countries might get a shock if they have never been there before."
The greens at Adelaide run at 15 seconds and are a bit slower than New Zealand greens.
''It's about repetition and you get more comfortable the more you play," he said. "The biggest difference is green speed and the line to the jack. You can play a much tighter line than in New Zealand and it allows you to play more attacking shots." McIlroy will marry promising Nelson female bowler Amy Brenton on January 26.
Speight's Invitation Singles
At a glance
Dates: October 19-22. Post-section play from Sunday afternoon. Final from 1pm Monday.
Venue: North East Valley Bowling Club.
Number of players: 32.
TAB odds: Shannon McIlroy $5, Steve Beel $50, Andy McLean $125.
