Re: top speed for a 21 super clipper with 356 cu. in

Posted by Joe Santana On 2020/3/1 10:09:23

Tim, I'd really like to understand this, but my pea brain (the left one) can't quite get its folds around it.

Maybe numbers would help. I have a 4.09 rear-end (differential gear?).

The fastest I've driven in the Duchess was 90 mph on a freeway (17 near San Jose) that was finished but was slated to open the next day. I moved a wooden barrier just enough. At 90 mph, I felt that if I opened the vent window even a crack, the car might spin around. I was a kid in 1960.

But on the way to my granddaughter's graduation from Santa Clara last year, I found myself doing 80 mph easily. I was on a freeway with light traffic and that's how fast most cars were going. I was just moving with the traffic, Officer. (I slowed to the speed limit.) But I was genuinely unaware of going that speed.

But I could honestly tell you I would not have the nerve to drive 80 mph in direct drive for fear of blowing up the engine, even if that couldn't happen. It would sound like that to me. Even going 45 mph without engaging the overdrive feels to me that I'm redlining. (I don't have tachometer, but maybe that would help me understand this.)

The mathematical formulas for calculating top speed are all over the road. Tire and wheel measurements, transmission gear ratios, differential ratio, rated horsepower, wind drag, tire drag, and probably more factors. I quit.

This all seems to Me, something like The Trial of Bumble the Bee, a kiddie song I learned. The bumble bee's body is too big and his wings are too small. "If you see one buzzing by, don't believe what you see with your eye; because science says, and figures don't lie, the bee, the bee, the bee can't fly."

I can go faster in overdrive than direct drive, I think. ??