Quote:
Originally Posted by MAStuart
I have a few questions concerning track width. I assume this is a measurement to the center of the tires. Is this correct? And the track width depends on having a certain width of wheel with the proper offset. Wheels with a different backspacing equals different track width. Is this correct? I also assume ride height also depends on how tall the tire is. If a taller tire is installed and nothing else is changed the ride height is raised. So without knowing the tire dia the ride height number is meaningless. Is this correct?
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Correct about the parts. Where to measure is another subject as one would need to know where any given technical inspector would measure. Data submitted was for a standard set of all the parts you mention. Even if the same parts were available few would use them for all kinds of reasons in this century. The forms cover lots of technical topics but they are not all encompassing and either have some on purpose misdirections or errors (bogus Ford part number for example for made just for endurance racing part, i.e. nothing a walk in customer could get at a Ford dealer). Then there were the optional parts of all kinds submitted in list form.
Cobras were registered with the Fédération Internationale de l'Automobile (FIA) race sanctioning organization soon after their creation. Then the cars were changed for many reasons and revised submittals were made. To have a hard copy of every submittal and revision or parts list means a nice little book of papers and if you have the FIA submittal for the 427 Cobra it’s a little thicker. Some collections included fairly good size hard copies of the pictures submitted.
The only good I know the original forms have is for time frame restorations of original race cars. Example: It does little good to know that the standard static compression ratio (SCR) was listed as 12:1. How many 1960s specification multiple carburetor and ignition points engines with that SCR are going to be put in cars mostly driven on the street with modern fuels with ethanol in them? Does knowing that the STANDARD main fuel jet for a 48 IDM carburetor set up by Shelby's works was a "165" do any good these days for street driven cars?
On ride height. Most of the time works race cars were higher off the ground than street cars. Street tires by mid 1963 were 25.48” outer diameter (Our measurements of two new old stock Cobra specific tires mounted on stock rims.). The listed optional street tire after summer 1963 was 26.02" in outer diameter (Our measurement of six new old stock tires with Shelby shipping labels to the customer on them.). The Speedway Specials and Stock Car Special tires were much larger in diameter. One of the Peter Brock drawings shows a 27” front tire and rear wheels normally were larger in every way. There was a series of photos made comparing a new summer 1963 Le Mans Replica beside a current new street car from many perspectives. The race car was noticeably taller than the street car.