Published on Fri, May 1, 1992
By: Len Frank
In 1992, the late Len Frank wrote his seminal piece on the Indianapolis 500, “the greatest spectacle in racing.”
Above: The 1913 Indianapolis 500 (Bain News Service/Public Domain)
The Indy 500, “The Greatest Spectacle in Racing,” is the world’s oldest race, the world’s richest, the world’s fastest. At one time it was the bastion of the backyard dreamer, the Gearloose Inventor, American Ingenuity, home-grown genius, and last year’s Grand Prix car.
Over the years, Indy has seen four wheel drive, front wheel drive, six-wheeled cars, twin-engined cars, all-independently sprung cars, cars with solid axles on both ends,
Diesels, two-strokes, turbines, mundane side valve stock blocks, fours, sixes, eights, twelves, sixteens, nitro-methane, gasoline, intercoolers, superchargers, turbos. Every trivia player knows that the winning car in the first race, the Marmon Wasp, was supposed to have had the first rear view mirror. Less known is that the Cornelian, a few years later, was the first all-independently sprung monocoque racing car.
This year, most of the starters will have come from the same factory (Lola) in England, and will be powered, most likely, by one of six basic engines. This year when the lights go green and the flag drops, thirty-three monocoque, mid-engined turbocharged cars, all powered by methanol, all powered by V-configuration engines, will drive for Turn One.
Stock-block engines (a misnomer—only the basic architecture is stock) will all be Buick V6s. For ’92, the two-valve Buicks have been allowed to raise boost pressure from 45″ to 50″ (at Indy’s near sea-level, about 11 lbs/sq.in boost) for all CART races (every race in the PPG series except Indy).
With the increased boost, horsepower goes from 690 to 720. Indy, however, is sanctioned by USAC and boost will be 55″—horsepower jumps to 785.
Brayton Engineering (Owned by Lee Brayton, father of Indy driver Scott Brayton–who drives a Chevy-Ilmor this year), works with Buick to machine, assemble, and develop the 209ci iron-block, aluminum-head, 90o, even-fire, V6 pushrod engines.
Buick supplies Brayton with raw crank forgings, block and head castings, ignition systems and electronic fuel injection management. Brayton builds or buys the gear-drive cams, titanium intake valves, roller lifters, Garrett turbo, etc.
In addition to the new boost allowance, Brayton has developed a seven butterfly intake manifold that helps drivability—it smoothes power, helps speed off corners on road
courses, doubles the mileage under caution-flag cruising, and makes pit exit easier and more controllable. Valve train has also been developed to increase reliability.
The price, low by Indy standards, is $83,500 including the new manifold. Rebuild cost is less than half that of a Cosworth or Ilmor V8. Goal is to get more top teams using Buicks and to get finishes to match their strong qualifying.
All other engines starting at Indy will be four-cam, four-valve per cylinder V-8s with aluminum blocks and heads and containing varying amounts of carbon fibre, titanium, and magnesium, and used as stressed members in their respective chassis.
The Cosworth DFX and Judd V-8s are the old hardware. Cosworths were developed for Indy from the Cosworth-Ford DFV three-liter, normally aspirated F1 engine that dominated grand prix racing from 1967 until the Honda epoch. McLaren Engines in the US began the Indy development of the Cosworth in 1975 and within a few years the versatile V-8 was the one to beat, obsoleting the Ford four cams, Offy variations and Chevy stock blocks.
It was CosworthCosworthCosworth until the Chevrolet-Ilmor came along in 1986—by 1988 it was all Chevy-Ilmor. Think of the Ilmor as the logical development of the Cosworth DFX. Mario ILlien and Paul MORgan left Cosworth to found Ilmor Engineering in England. Instigator was Roger Penske who eventually involved Chevrolet. Chevy supplied the engine management system and worked on cam problems as well as providing substantial amounts of cash.
Ilmor designed a very compact combustion chamber that, combined with slightly smaller exterior dimensions, and other hidden wonders gave the new engine both a power (partially from a higher rpm limit–they admit to 11,400) and chassis aero advantage over the Cosworth. The Ilmor features lighter weight, shallow, low, structural sump that
incorporates the main bearing caps, cam gears at the flywheel end, narrow included valve angle (24o), high exhaust manifolds (for chassis aero advantage) and carefully packaged pumps and ancillaries as the chief advantages over the old DFX. Originally a Penske-only weapon, CART rules demand open availability after three years so Ilmor-Chevy distribution is widespread and Chevy is working to lower the cost of ownership/leasing/operation.
For 1992, Cosworth has responded with their new XB, officially the Ford-Cosworth XB. The XB is 15 percent lower and 19 percent narrower than the older DFS (latest version of the DFX). Ford claims a weight of 260 pounds dry, down from about 330. The rpm limit has been extended again, to 12,700, but all other performance figures are confidential. “We have some technology to protect,” says Lee Morse, Ford’s Manager of Performance Operations for North America.
Much of the technology comes from the F1 engines developed to replace the old DFV—Ford and Cosworth feel that they were nailed by the FISA change from the 1.5 blown formula to the current 3.5 normally aspirated, and the XB is a way to keep from wasting man-years of R&D.
The XB appears to have a slightly-more than 90o included bank angle. Ford hints at the same kind of sump-main bearing-girdle arrangement that the Ilmor uses (used on many engines before Ilmor), large aerodynamic gains (both lower drag and more downforce as a result of less frontal area, smoother, tighter cowling, and larger, better-shaped under car tunnels).
Water and oil passages are integral whenever possible to help reliability, lower vibration levels than other Indy engines (the flat plane cranks used for exhaust tuning purposes are shakers—the Ilmor was designed with rear-mounted timing gears to reduce balance problems—the early DFVs were especially bad), an “exceptionally wide” power band,
and higher rotational speeds than any other Indy engine are claimed. Engine management electronics are by Cosworth for the time being while Ford develops a more advanced, more complex unit.
Since boost is fixed (and carefully monitored) at Indy, horsepower gains come primarily from higher rotational speeds. This generally means shorter strokes/bigger bore, longer connecting rods, and lower reciprocating mass. Ford and Cosworth comment: “no comment.”
Drivers will be the Andrettis, father and son, for Newman-Haas Racing with Lola T9200 chassis (Haas is the importer) suitably designed to fit the new engine, and Eddie Cheever, racing for Chip Ganassi in a similar car.
Never one to be left without an Unfair Advantage, Roger Penske, in the form of Team Penske/Marlboro Racing have come along with the The Chevrolet-Ilmor Indy V-8 “B” for Roger Mears and Emerson Fittipaldi in new Marlboro Penske Chevy 92 chassis.
Like Ford-Cosworth, the “B” is all “no comment,” “CONFIDENTIAL,” and of unobtanium construction. Unlike the all-new XB, it is a modification of the existing Chevy Indy V-8 (Ilmor “A”), with new heads, new electronics (GEN-III from Delco), new external accessories and intake manifolding. Like the XB, the “B” is substantially narrower and lower, and allows better aerodynamics. Chevy is also claiming lighter weight and more power.
No word from Judd, but Truesports, who have been handling the Honda-based V-8 have Scott Pruett sitting in front of a Chevy Indy V-8. Porsche dropped out a while back and Alfa, after a disappointing season with Patrick Racing and Danny Sullivan, appear to have left USAC/CART for the foreseeable future.
Goodyear will still be the standard rubber at The Speedway. They are supplying Superspeedway Eagle radials, 10.0″ X 25.5″ front, 14.0″ rear width, with 27.1″ right rear, and 26.92″ left rear, mounted on 10 X 15 wheels front, 14 X 15 rear. A set, by the way, will set you back about $1200, mounting and balancing not included. After the track was resurfaced providing better traction in
89, compounds were adjusted to restore durability. For92, Goodyear has worked on uniformity to make chassis tuning a bit more of a science and less an art (racing tires are largely hand built). Goodyear promises a new sidewall treatment but will not say whether it is just cosmetic.
The late Len Frank was the legendary co-host of “The Car Show”—the first and longest-running automotive broadcast program on the airwaves. Len was also a highly regarded journalist, having served in editorial roles with Motor Trend, Sports Car Graphic, Popular Mechanics, and a number of other publications. LA Car is proud to once again host “Look Down the Road – The Writings of Len Frank” within its pages. Special thanks to another long-time automotive journalist, Matt Stone, who has been serving as the curator of Len Frank’s archives since his passing in 1996 at the age of 60. During the next few months, we will be re-posting the entire collection of “Look Down the Road”, and you’ll be able to view them all in one location under the simple search term “Len Frank”. – Roy Nakano