How many colectors have one of these?

[wa2ise]

The 57 Ford Fairlane 500 I mentioned before had overdrive. My brother was driving it on the highway, and he decided to give it a try. And it worked! "We have overdrive!" At the time I didn't understand what that was, but I didn't ask as I didn't want to risk being called an idiot... He was my older brother by 6 years. As I now (mis)understand it, overdrive is when the car tires rotate faster than the engine crankshaft. Which makes sense to do only at highway speed.

[jr_tech]

Originally Posted by wa2ise

As I now (mis)understand it, overdrive is when the car tires rotate faster than the engine crankshaft. Which makes sense to do only at highway speed.

No! you neglected the final drive reduction ratio, on the order of 2.5 to 4 :1. Do the math... If you have a tire that is 2 feet in diameter, the circumference is about 6.3 feet... if it was turning, say 2500 R.P.M. , that would be almost 16,000 feet per minute, or about 3 miles per minute!

jr

[wa2ise]

Originally Posted by jr_tech

No! you neglected the final drive reduction ratio, on the order of 2.5 to 4 :1.

DOH! Looks like I misunderstood it...