In RACER magazine and on RACER.com, we're counting down to the 100th Anniversary Indianapolis 500 with a series of fascinating insights on “The Greatest Spectacle in Racing.”

This week, we rewind to 1991 and take a look at the dramatic Month of May that culminated in a fourth Indy 500 win for Brickyard great Rick Mears, and recall the fourth wins of those other members of the “Quadruple Club,” A.J. Foyt and Al Unser.

“AND RICK'S GOT HIM RIGHT BACK IN TURN 1!”

It was one of racing's fundamental truths: Rick Mears (LEFT) didn't crash at the Indianapolis Motor Speedway. Ever. So, when his Penske-Chevrolet PC-20 pounded the Turn 1 wall the afternoon before the 1991 Indianapolis 500 Pole Day, there was genuine shock and surprise.

But if anybody thought Mears' first accident in 14 years of competing at Indy showed a chink in the laid-back Californian's armor, they were sadly deluded. Instead, it set the stage for his fourth and most spectacular win at the Brickyard.

Prior to the crash, Mears had been among the quick guys, running with the likes of his teammate, Emerson Fittipaldi, Michael Andretti's Newman/Haas Lola-Chevy, and the fastest (Kevin Cogan) and bravest (Jim Crawford) of the Lola-Buicks. Typically, even at his quickest, Mears looked like the smoothest, least hurried guy in the place.

Then, a little after two in the afternoon on “Fast Friday,” the squeal, boom and grind of a car hitting the wall – hard.

The rear of the Penske was destroyed, but Mears climbed out unaided. As he headed to Methodist Hospital for checks, his ever-efficient crew began preparing the backup car, which he'd driven for a few laps the previous Monday.  

As soon as the cause was traced to a faulty wheel nut pin and the team was satisfied it was a one-off, Roger Penske let Fittipaldi back on track. It was just before 4 p.m. and the Brazilian soon turned in the day's fastest lap of 226.705mph.

Then, at 5:02 p.m., all eyes turned to Penske No. 3T as Mears, back and cleared to drive, climbed aboard. Seven minutes later, with a red, white and black collage of paint and rubber adorning the Turn 1 wall, he swept across the line with a 226.557mph lap. Normal service resumed.

And business as usual for qualifying, too.

In the morning warmup, Mears, Fittipaldi and Cogan all ran 226mph-plus laps, pointing to a record-breaking Pole Day. But the building heat and humidity of the day slickened the track, leaving Mears to work hard in the car – not that his effortless-looking progress gave much hint of that to the fans in the stands – for a four-lap average of 224.113mph and the provisional pole.

When Penske waved off a run by Fittipaldi late in the afternoon and light rain moved in to deny him another run, Mears' sixth Indy pole was set.

Fifteen days later, on an overcast race day, the early acts played out as classic Mears. For him, the “500” boiled down to being in the right place with the best-handling car for the final shootout. Everything prior to that was about biding your time, scoping the opposition, fine-tuning.

After Mears relinquished the lead on lap 11, Fittipaldi, Al Unser Jr. and Michael Andretti traded the lead for the next 300-plus miles, with Mears circulating top five. But on lap 139, with the momentum building, Mears was up there swapping the lead with Fittipaldi and Andretti.

On lap 171, three became two as Fittipaldi peeled off with gearbox problems. Andretti led until 183; Mears took over again on lap 184.

Then came the defining moments, set up by Danny Sullivan's Alfa Romeo-powered Lola, which expired in a smokescreen on lap 184.

At the restart on lap 186, with Andretti right behind, Mears passed the lapped cars of Unser Jr. and John Andretti, but lost momentum doing so. That allowed Andretti to pull out of the tow, sweep past Mears on the outside through Turn 1 and take the lead as they entered the short chute. It was a gutsy, race-winning move.

But, one lap later, with the Penske sucked up onto the new leader and Andretti hugging the Turn 1 apron, it was Mears holding his breath as he entered the turn faster than he had all day. He jinked to the high side for a near-identical pass (ABOVE) as the crowd erupted in excitement and disbelief.

As Mears began to put a little daylight between himself and Andretti, the final twist came courtesy of Michael's father, Mario, who coasted to a halt near pit entry with an engine problem on lap 191. It took three whole laps to tow away the elder Andretti (not helped by his sudden and inexplicable inability to catch and hold onto a tow rope…), with Michael right behind Mears once again for the restart on lap 195.

No way was Mears letting this one get away. He drove those final laps as if on a qualifying run – maximum concentration, inch-perfect accuracy at 220mph-plus – to take the checkers 3.149sec ahead of Andretti and become the Indy 500's newest four-time winner. A.J. Foyt and Al Unser had a new member in their exclusive club.

THE FIRST TO FOUR

While Mears had to wait only three years after his third win to claim his fourth place on the Borg-Warner Trophy, Foyt had to wait a full decade beyond his third and final 1960s Indy triumph in '67. He'd had several near-misses, being thwarted in both 1975 and '76 when rain caused the race to be flagged early, and so Supertex came loaded for bear in 1977. 

Much of the race, however, was dominated by Gordon Johncock's Wildcat-DGS, which led 129 laps and enjoyed a 16sec lead over Foyt's Coyote-Foyt (the old Ford four-cam V8 which Foyt's engine shop now built) after the final pit stops. But, under relentless pressure from Foyt, Johncock pushed his engine beyond its limits on a blazing hot day, and coasted to a stop with a failed crankshaft just 16 laps from the finish. Foyt (ABOVE LEFT) motored through into history, beating polesitter Tom Sneva to the checkers.

Unser's road to the quadruple was nearly as long, and required an even more dramatic plot to reach its successful conclusion.

After arrival at Indy that May without a ride, Al took over the third entry at Penske Racing when Danny Ongais was injured during practice in one of the team's PC-16 chassis, which had proved disappointing and were being shelved for all Penske's drivers in favor of year-old March cars. Unlike teammates Rick Mears and Danny Sullivan, though, who were running the more powerful Chevrolet engine, Unser had to make do with one of the increasingly dated Cosworths – indeed, his whole car had been recalled from showcar duty in the foyer of an hotel.

But, an attrition-filled race that felled all the Chevy runners – including Mario Andretti, who led a staggering 170 of the 200 laps – was precisely what the mechanically savvy Unser needed, and when new leader Roberto Guerrero stalled in the pits on his final stop due to a damaged gearbox, the New Mexican surged past for his fourth Indy win (ABOVE RIGHT).

• 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.

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