Legendary racing engineer Mario Illien of Illmore Engineering talks about the famous Mercedes-Benz 500I development
Standing in front of an auto-engineering legend, you get not only the sense of the humbleness that comes with race-engineering triumphs and failures but also the mirth that comes from the sport's mischief.
Covering this year's Indianapolis 500, we got a chance to meet and chat with the legendary Mario Illien, the Swiss-born mechanical engineer involved in one of Indianapolis' greatest secrets.
Illien has been involved in racing since the 1970s when he began work for his boyhood hero, Jo Bonnier (later killed at Le Mans in 1972). He really honed his racing chops at Cosworth in England, where he met another engineering legend, Paul Morgan. The two eventually formed Illmore Engineering.
"We didn't have any money," Illien told us as we stood in the Brickyard garage of KV Racing as part of Littelfuse's Speed2Design project. "So we called up Roger Penske. We sent him a handwritten budget and later met him at Red Bank (N.J.) on a Sunday afternoon. After two hours, we made a deal. That's how we started in '84. We have been partnered ever since."
The mischief came about a decade later when they were working with Mercedes. The racing gods had slowly relaxed the rules to help Buick, which had struggled at Indianapolis, become more competitive, according to Illien.
A rule requiring stock blocks to contain some production-based parts was eased in 1991. Two years later, Illmore and Penske, working in total secrecy, exploiting the rules relaxation, devised a new pushrod engine capable of more than 1,000 hp.
"We designed and made the engine in a half year. We did three months of development then we came here racing. Roger set up a shop where you only worked at night in Redding, Pa. We tested on tracks that Roger owned. Everything was sealed off."
"We announced the program one week before we entered Indy. We had 1024 hp, 200 more than anyone else. We were just smoking it."
That Mercedes-Benz 500I (209 cu in.; 3.42 l), was plunked into the Penske PC-23 chassis.
Penske cars owned the pole and the outside first row at the start of the race, and when the 500 miles had been traveled, Al Unser Jr., the pole sitter at 228.011 mph, won for Penske, lapping the field incredibly with 16 laps remaining in the race.
By way of context, in this year's Indy 500, engines were limited to 550 hp.
There is an excellent resource to read more about this engine development at Forix Autosport
[Learn more about the Indy 500 at Littelfuse's Speed2Design site.]