The bore is three times smaller, so the displacement is nine times smaller because of that. The stroke is also three times smaller, so the displacement is another three times smaller because of that: 27 times smaller in all.

Sigh... once again my ignorance is displayed for all to see.

You are absolutely right. I actually had to sit down and plug numbers into a formula and prove to myself empirically that yes, that incredible V-12 Ferrari engine really was only eight cubic inches displacement.

On the off chance that anybody cares, here are the numbers. For simplicity, I pretended that the engine was "square", that is, bore and stroke were equal.

Disp. = Pi x 1/4 x B^2 x S (where B = Bore, S = Stroke)

3600 = .785 x B^2 x S

Since S=B, then

3600 = .785 x B^3

4585 = B^3

B = 16.61
S = 16.61

Reality Check: 3.14 x 1/4 x 16.61 x 16.61 x 16.61 = 3597 (The missing 3 CCs are from rounding errors)

So, reduce the dimensions by a factor of three, and we get

Disp. = 3.14 x 1/4 x 5.54 x 5.54 x 5.54 = 133 CCs.

Interestingly enough, given the original premise of 40% over-square design (stroke = 60% of bore), the 1/3 scale displacement still remains at 133 CC.

This makes sense when looked at from Peter's perspective that the bore being three times smaller yields a 9x reduction while the stroke being three times smaller yields an additional 3x reduction, but it was non-intuitive to me until I played with the numbers. Of course, if I had been thinking properly, I would have considered the hypothetical case of reducing the bore by a factor of three and leaving the stroke at the original dimension, and I would have seen immediately the error of my ways.

I guess the same factors would apply to the weight of the car as well. If the original car weighed, say, 2160 pounds, then the model would weigh just 80 pounds. It would be interesting to know the horsepower rating of that engine, find out if it were producing 1/27 the power of the original. That would probably put it in the 12--15 HP range.

So, Bonzi, your revenge is complete. I bow to your superior math!

tanstaafl.