I'm not sure it's as simple as that, as Tom says, the tallest available ratio was 3.08. The Mulsanne Straight was 2 1/2 miles long (though still 2 1/2 miles long, 2 chicanes were added after 99, when 2 Mercedes CLR's literally became airborne after crossing the Mulsanne "hump", Mulsanne top speeds had reached 250 mph by then!), the entire race distance was over 8 miles long. A car had to maintain that 150+ mph for more than 1 1/2 miles. But, Le Mans also has some very slow speed turns, I think you may have needed even more than a 3.08 for a competitive balance. I never thought about it before, but I'm really sort of curious as to what rear they would have run.

In 1960, Corvette News did a article on the 60 Le Mans race and the Corvettes. Unfortunetly there are no specs given on the cars. The author of the article (who's name is not given) descibes a lap at Le Mans, a portion of his description is:

"From the Esses there is a brief straightaway, but you must be wary as you approach the extremely diffucult Tetre Rouge Corner. Brake down - because at anything over 40 mph, you will find yourself in the sandbank that lies off Tetre Rouge. As you come out of this corner you find yourself barrelling down the fastest and most famous straightaway in sports car racing - the Mulsanne Straight. You quickly build to over 155 mph, flat out. You should have reached this speed about one third of the way along the straight........"

"Some 500 meters from Mulsanne Hairpin you begin to brake down - ever so gently. In the 500 meters you must reduce the Corvette's speed approximately 90 miles per hour. You must, if you desire to negotiate the turn properly."

"It is a mile from the Mulsanne Corner to Indianapolis, .... There is a slight righthander followed by a much sharper lefthander, a short straight between thick pine woods, then a 90 degree turn to the right at Arnage Corner. Your speeds through this series have gone from 140 to 90 to 60 to 30 miles per hour. You are still two miles from the checkered flag........ You zoom by the pits at 130 mph and you are home. It has taken just over four minutes to run the complete circuit."

During one lap at Le Mans in a 1960 Corvette, speeds varied from a slowest of 30 mph, to a top speed of 155 mph. If, as the article says, you come off Tetre Rouge at 40 mph and reach top speed of 155 within 3/4 of a mile (1/3 of the 2 1/2 mile long straight), could a 1960 290 horse fuelie motor do that with a 3.08 rear? I don't consider the 283/290, or any of the early fuelie motors, as being very strong on low end torque. I think rear ratio in the mid, or maybe even upper 3's, might have been needed???

 

I love the efforts at aerodynamic imrovement on C1 #3 in the lower picture. Rear of hood is propped open to release trapped air up rather than down, reducing lift. The headlight buckets are partially raised, forming mini-spoilers. Also jacked rear, unless driver is panic-braking!

 

Nope, the near car is the #3 Mickey Thompson 427 "Mystery Engine" car, and the #4 far car is a (stock) 327 Z06 in the RAIN on the Daytona banking. All of the hood buckling, headlight door rolling and lifting are due to aerodynamic loading.
Mickey Thompson had cut "doors" in the inner fender of the front wheel wells so that the driver could check the wear on the front tires, however, when the rains came, fog/mist from the heated water entered the cockpit and made the 427 car undrivable because of limited/no vilibility.
Note the size of the Firestone T-170 race tire.

 

I think the white (or light colored) car, in the picture on the banking with the Mickey Thompson car, may actually be the # 17 ZO6 that was driven by AJ Foyt in that race. The Mickey Thompson 427 car was driven by Junior Johnson in the race. The race was the Daytona Continental, which later became the Daytona 24 Hours.

I've never seen a picture of the 427 in that car. I've always wondered how deep it was set in the chassis, or what it used for an intake, that it fit under the stock 63 hood. It may be over simplifing it, but the mystery 427 used a block that was dimentionally similar to the 348/409 block and 396/427 "porcupine" style heads. Is it possible that the blocks deck height was short enough that the engine fit under the stock hood? The mystery 427 was the same engine that Junior Johnson, and others, raced in 63 Impalas in NASCAR that year.

 

Glenn I believe you are correct. The white car is the #17 AJ Foyt car.

 

u have me mocking up a deflector right now! my 61 has an open BB scoop, which i think works against it. the deflector should allow it to pull more air thru the radiator and reduce drag.

 

Glen, it took me a while, but here is a picture of the 427 engine in the car.

 

Wow, how the heck did they close the hood? Doesn't look like there's enough clearence without an air cleaner, let alone with one. That's a pretty tall manifold, looking at the rough finish of the casting, it almost has a hand made or prototype look to it. I like the Mallory distributor (magneto?). David, thanks for the picture.

 

That's a Scintilla-Vertex magneto.

 

With all these early Vettes racing, what carbueration, intake, & head combination were being used on the 283/327 engines?? And then the '63 Grand Sports with 377 and 427 eng blocks ?

 

283s and 327s had single quads or Rochester FI.

377 Grand Sports started with single air-meter Rochester FI, experimented with dual-meter FI, then ended up with quad Weber carbs. FIA spec sheet called for dual-plug hemi heads, but I don't believe any of these made it as far as a race track.

To my knowledge, all cars that later received 427 "mystery" motors used single quads.

 

Mechanic to Mickey: "Naow lookah here, Mick, this here Holley is sittin' on a hah-rahz mannyfold. If y'all try to put a ayah-cleenah onnit, the hood cain't close!

Mickey Thompson: "Then run it without. Chevy GAVE me the motor, if we win nobody'll care if it's junk afterwards."

 

Thanks John

 

The Grand Sports started out with stock 360hp Fuel Injected engines and fairly stock looking body work. Then the 3 coupes were taken back to the factory and fitted with aluminum 377cid engines with Webber 58DCOE and body panels modified for better air flow and wider tires.

 

Chevrolet engines are tested at full throttle for 200 hours at peak torque to peak HP. For a '60 fuelie that's from 5000 to 6200 rpm.

 

My car seems reasonably stable at ~120:



Stable enough that I could take this (in CO a few years later):



I'm not saying that I'd do it all the time, and I do run radials (as opposed to those pie-pan originals) but...that's what these cars were made to do!

 

Why didn't the C1s use a front spoiler? Wouldn't that help keep the nose down?

 

Ummmmmmmmmmmmmmmmm, I'm thinking that kind of aerodynamic knowledge and technology hadn't yet come onto the scene. Remember, you talking 1950s----------not 1970s and later.

Tom Parsons

 

Tyler says it takes a blizzard or monsoon for that to happen.