Mercedosaurus Rex at Indianapolic Park
Appendix 1: Specifications
Author
- Henri Greuter
Date
- December 4, 2009
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- March-Porsche 90P - The last oddball at the Indianapolis Motor Speedway, by Henri Greuter
- Penske-Mercedes PC23-500I - Mercedosaurus Rex at Indianapolic Park, by Henri Greuter
- Introduction
- Part 1: Penske Racing at Indianapolis - new standards
- Part 2: Ilmor Engineering at Indianapolis
- Part 3: Mercedes, Benz and Mercedes-Benz at Indianapolis up until 1993
- Part 4: Equivalency formulas - waiting for things to go wrong
- Part 5: Stock blocks - keeping them rolling and promoting 'Born in the USA' technology
- Part 6: Indianapolis 1991 - Chevy And Rich Team owners
- Part 7: The Speedway narrowed, its speeds lowered
- Part 8: The forerunner
- Part 9: Pre-May '94 plans
- Part 10: Penske PC23 - a home for the engine
- Part 11: The 1994 Indycar season until mid-April
- Part 12: The unfair advantage and when others have it
- Part 13: Practice during the 1994 'Month of May'
- Part 14: Other bespoke-design 209s
- Part 15: From the last weekend of May '94 to the end of the season
- Part 16: Could the Mercedes Benz 500I have been stopped in time?
- Part 17: Creating an extinct species without it being forbidden, initially at least
- Part 18: The 1995 '500' - Did the Mercedosaurus bite its masters after all?
- Part 19: A possible twist of fate for Rahal-Hogan and Penske as a legacy of the 500I
- Part 20: Re-evaluation of our verdict
- Part 21: PC23's further active career after 1994
- Part 22: USAC’s points of views and some answers
- Part 23: The loose ends that didn’t fit in anywhere else and the epilogue
- Part 24: "Plan your work; work your plan" - Chuck Sprague on the PC23
- Appendix 2: Car and driver appearances and performances during the Month of May 1994
- Appendix 3: Chassis, entry, practice and race numbers in 1994
- Appendix 4: PC23's 1994 results sans Mercedes Benz 500I
- Appendix 5: PC23's 1995-'96 results sans Mercedes Benz 500I
- Appendix 6: A reflection on the PC23 chassis used by Team Penske in 1994
- Appendix 7: A review of Beast by Jade Gurss
Specifications of the Mercedes-Benz 500I were hardly released up until the 500-miles race at Indianapolis. The project was carried out in secrecy, about everything there was to know about the engine remained a secret too. See for example the specifications sheet as found in the Mercedes press kit released during the month.
Karl Ludvigsen devoted a lot of attention to the engine in his books Mercedes-Benz Quicksilver Century and Prime Movers, both on sale in 1996. In Part 9 I gave a description about the engine construction, based on these two books.
The specifications as I list them here are a combination of data found in Ludvigsen's books Prime Movers and Classic racing engines and some quotes by Mario Illien in the Louis Schwitzer Award Media kit, and some data provided by Patrick Morgan during the Summer of 2014.
| Ilmor type | 265E |
| Designation | Mercedes-Benz 500I |
| Configuration | V8, vee angle 72 degrees, single turbocharger. 2 valves per cylinder, operated by pushrod system, single camshaft operated |
| Bore * Stroke, Capacity | 97 mm * 58mm, 3429cc |
| Bore/Stroke ratio | 0.6 |
| Compression ratio | 11.0 |
| Connecting rod length | 116.0mm |
| Rod/crank radius ratio | 4.0:1 |
| Main bearing journal diameter | 58.0mm |
| Rod journal diameter | 50.0 |
| Inlet valve diameter | 52.5mm |
| Exhaust valve diameter | 39.7mm |
| Length pushrods | "As short as possible" |
| Rocker adjustment | "Mechanically" |
| Lubrication and water pumps | Similar to Ilmor 265/D but modified to deal with slower crankshaft speeds |
| Engine control | Delco GEN-IV |
| Boost | 1.86bar (55 inch mercury) |
| Turbocharger | Garrett AiResearch TA74, built according to USAC specifications |
| Peak power | 1024bhp at 9800rpm1 |
| Corrected piston speed | 24.1m/s = 4.823ft/min |
| Maximum safe rpm level | 10,500 |
| Peak Torque | 755Nm = 557lb ft at 8000rpm |
| Weight | 123.0kg = 273.4 pounds2 130.0 kg3 |
| Length | 561mm |
| Width | 510mm |
| Height | 654mm |
| Center of Gravity | 225.90mm above lowest point of sump3 |
1. This 1024hp figure is corrected for temperature and atmospheric conditions. Uncorrected the power output was between 965 and 970hp.
2. Weight as listed in Prime Movers. Classic Racing Engines lists the engine weight as 132kg, so perhaps a typing error that should have read 123kg?
3. Data as provided by Patrick Morgan.
For good measure, the dimensions of the Ilmor/D engine normally used in the Penske PC23 during the 1994 season were: Vee angle of 82 degrees resulting in L*B*H dimensions of 561 * 555 * 566mm. The weight was 124kg. According to the Marlboro Racing press kit of 1994, the Ilmor/D produced 740hp at 12,500rpm and had a peak torque of 360lb ft (= 488Nm) at 8500rpm.
The following specifications found in the Marlboro Racing press kit (with the car being told as appearing with an Ilmor quadcam engine) were given for the Penske PC23 car:
| Chassis type | 94 Marlboro Penske Ilmor Indy V8 |
| Contructions | Penske Carbon Fiber |
| Constructed at | Penske Cars Ltd, Poole, Dorset, England |
| Weight | 1,550lb |
| Weight distribution (front-rear) | 41/59 |
| Wheelbase: | 115in |
| Length | 190in |
| Shock absorbers | Penske |
| Radiators/Heat exchangers | Modine |
| Wheels | BBS |
| Front | 10x15 |
| Rear | 14x15 |
| Tyres | Goodyear Eagle Speedway Special Radial |
| Front | 25.5in x 9.5in x 15in |
| Rear | 27in x 14.5in x 15in |
| Instruments | Pi/Ilmor/Penske |
| Battery | Delco |
| Fuel cell | Goodyear Crashworthy |
| Fuel capacity | 40 U.S. gal |
| Fuel | Methanol, supplied by Mobil |
| Steering | Penske, rack & pinion |
| Turns, lock to lock | 1-1.5 |
| Suspension: | |
| - Front | pushrod |
| - Rear | pushrod |
| Brakes | Alcon disc |