I want to thank you, bracketracer, for your comments, for they've caused me to direct further thought toward the value of my spreadsheet. I'll be adding the following (or something similar) to the instructions:
As you're aware, there are two methods commonly used to determine the car's center of gravity height. One is to measure the camshaft height (pushrod V8 engine is assumed) and assume that to be the same as the CG height for the entire car. The other is to tilt the car forward on its front tires to a specific angle and calculate the CG height, noting the change in front wheel loading between the horizontal and tilted positions.
Surprisingly, the first method will often yield a fairly accurate result. The engine is the heaviest single component and a number of other heavy components have CG heights essentially the same as the tire radius. It just happens to work out that, when the engine is mounted in a "typical" position, the camshaft height is quite close to the car's CG height. But, there are always exceptions. The Ramchargers' first car was a '49 Plymouth powered by (of course) a hemi. The valve covers were pressed right up against the underside of the hood. This is, admittedly, a radical exception, but it illustrates the weakness of the method.
The second method can yield quite accurate and reliable results. There is a certain amount of danger involved, but this problem can be overcome with reasonable caution. If the result is to be accurate, if follows that care must be taken to accurately record the wheel scale readings and to accurately measure the angle of tilt. Also, some equations being used assume front and rear tires to be of the same radius. This might not be a valid assumption. Page 31 has a spreadsheet for this method which allows input of individual (front and rear) tire information.
The tabular method (Page 39) can be considered to be an extension of the first method, with the intent of minimizing the first method's weakness. Instead of considering only the CG height of the engine and instead of assuming a "typical" relationship between engine mounting and wheels, you can expand your investigation as far as you desire.
Perhaps you will include only a few of the heavier components. These might include engine, transmission, driver, battery, and radiator. You might then lump together the weights of suspension components, axle, wheels and tires, and consider them all to have a CG height equal to the tire radius. This might seem crude, but it's a whole lot better than using the engine camshaft height alone, which wasn't all that bad an assumption in the first place.
If, on the other hand, you're working with a sprint car, you might want to carry the process much, much further, taking into account every piece of tubing and every piece of sheet metal. This is at least possible with a sprint car, but virtually impossible with a production unibody car.
Thanks again, bracketracer.
http://www.racetec.cc/shope