In RACER magazine and on RACER.com, we're continuing our countdown to the 100th Anniversary Indianapolis 500 with a series of fascinating insights on “The Greatest Spectacle in Racing." This week, we take a look – or, rather, a listen – at a short and simple phrase, spoken just after the balloons are released and heading skyward, that's always guaranteed to make the Brickyard crowd roar.

THE MOST FAMOUS WORDS IN RACING

“Gentlemen, start your engines!”

It's the most famous phrase in racing – one that's evolved in recent years to reflect the growing gender equality in the Indianapolis 500's starting fields. But the dramatic prelude to 33 race engines exploding into life started out as a low-key improvisation that only gradually evolved into the climactic moment it has become.

In the early Indy 500s, the start of the race was counted down by a morning-long succession of aerial bombs, culminating in the bomb signaling the drivers to fire up their cars.  In much of Seth Klein's tenure as chief starter from 1934 to his retirement after the '53 race, the final bomb was accompanied by his twirling of a furled, green flag above his head.

By all accounts, the engines would then begin to burst into life in ones, twos and threes, not the almost instantaneous volley of noise we hear today. It could have been a spectacular precursor to the action…but it wasn't.

Plenty of people involved in the race wondered how the moment could be made more dramatic, but it took a showman friend of track president Wilbur Shaw to finally do things a little differently.

John “Irish” Horan was a former circus barker who'd recently formed a traveling auto “thrill show.” He'd joined the public address staff at the Speedway in 1948 and decided before the '51 race that he'd mark the signal to start the engines with his own little addition over the P.A. As the bomb went off, Horan opened his mike and with little gusto uttered the words, “Gentlemen, start your motors.”

Whether he actually said “motors” instead of “engines” is up for debate. In fact, there's some speculation that it was 1950, or maybe even '48, when he first said something to accompany the final bomb. Adding further confusion, other sources say that Klein was the first to say it – but only through a megaphone and for the benefit of the competitors themselves.

Anyway, what does seem to be indisputable is that Horan was the guy who first said something over the P.A. (unless you know differently, that is…).

By 1953, Shaw himself was issuing the command, “Gentlemen, start your engines,” with a microphone held close by to allow the whole Speedway to hear. By now, it was growing into one of those spine-tingling Indy 500 moments and would be accompanied by a roar from the grandstands.

In October 1954, Shaw was killed when the small aircraft he was traveling in crashed near Decatur, Ind. For the following year, track owner Tony Hulman decided to take over from the man who'd done so much to build and revive the fortunes of the Speedway after it fell into disrepair during World War II.

With growing panache, Hulman (RIGHT, pictured giving the command in 1970) would continue to give the command up until the 1977 Indianapolis 500, after which he would shortly pass away from cancer. But, for such a key figure in the history of the Indy 500, it was apt and fitting that Hulman's final command should be a groundbreaking one.

After trying and failing in 1976, Janet Guthrie became the first female driver to qualify for a “500” in '77, and speculation was rife as to how Hulman would modify his command – some even going as far as saying it should remain unchanged, because the command was addressing the guys holding the starters, not the drivers…

Come the moment, with anticipation at fever pitch, Hulman delivered his eloquent variation: “In company with the first woman ever to qualify at Indianapolis, gentlemen, start your engines!”

For 1978, Hulman's widow, Mary Fendrich Hulman, took over the duty and, in deference to Guthrie's second start, called out, “Lady and gentlemen, start your engines!”

Fendrich Hulman's last command came in 1996 (LEFT, she's pictured giving the command in 1983), just a couple of years before her death in April of '98, but her daughter, Mari Hulman George, had already substituted for her in '81 and would take over from her in '97 – a role she continues to perform to the present day (see video BELOW).

Recent years have witnessed multiple female starters in the “500” and the command given has evolved into “Ladies and gentlemen, start your engines.” What hasn't changed is the tumultuous roar and incredible surge of anticipation that always follow that handful of words.

• Trivia corner: When a race has to be restarted because of rain or a serious accident, the command that's usually given is, “Gentlemen, restart your engines!” or a variation depending on whether there are female drivers in the field. Those restarted races include 1967, '73, '82, '86, '97, 2004 and '07 and, in '82 and '04, it was legendary track announcer Tom Carnegie who gave the command over the P.A.

NEXT WEEK Some famous drivers make their Indy 500 debuts – with mixed results.

• For tickets to the 100th Anniversary Indianapolis 500 on May 29, 2011, CLICK HERE.

For more insight on the history and heritage of the Indianapolis 500, check out legendary Indianapolis Motor Speedway historian Donald Davidson's blog HERE on Indianapolismotorspeedway.com.

To get up close to racing history, visit the Indianapolis Motor Speedway's Hall of Fame Museum. Find out more HERE.

Follow RACER's Countdown to the Indy 500's 100th anniversary in the magazine that takes readers inside the world of auto racing like no other. CLICK HERE to subscribe.