[Volume XXVII
THE CHICAGO BANKER
50
Do You Fully Understand the Automobile Power Chart?
(From “The Sales Booster/* circulated among Winton Six salesmen )
so low after each power stroke that it represents no pressure at all.
The reason for this is shown in the statement above the top line, “Idle.”
When a piston is idle, that is, when it is not actually producing power, it is not exerting pressure.
On a five-inch stroke, power is actually produced for approximately only four inches. On the rest of the stroke there is no actual driving pressure.
Therefore, on the four, there is always an interval of no power before the next power stroke takes hold.
And on the four, this interval occurs four times on every cycle.
A cycle, you recall, means two complete revolutions of the crank shaft. *	*	*
With a five-inch stroke the distance of power piston-travel is 20 inches.
In the four, power is produced for a distance of (4x4) 16 inches.
That leaves four inches of no power on each cycle.
In the six, power is produced for a distance of (6 x 4) 24 inches.
Which gives four inches more of power piston-travel than the distance of the cycle.
*	-x-	*
This is made possible by the fact that in the six the actual pressure of one power-stroke does not reach its conclusion before the pressure of the succeeding power-stroke takes hold.
For that reason there is never an instant of no power in the six.
So the line of “actual pressure” is shown in the six chart to be always above the line of no pressure.
This merger of power in the various cylinders gives the six continuous power.
As against intermittent or jerky power in the four.
*	* *
Continuous power is physically, mechanically impossible in one, two, or four-cylinder motors.
Continuous power and six cylinders are inseparable.
* * *
This, in brief, is the “why” of the power chart.
From these premises your talk should lead through the advantages of continuous power, which subject is fully presented in our latest booklet, “ Jerks and Repair Bills vs. Continuous Power.”
*	-*	-x-
“Jerks and Repair Bills vs. Continuous Power” will be sent to any address gratis upon request. Write to The Winton Motor Carriage Co., 100 Berea Road, Cleveland, Ohio.
Every Winton Six salesman needs to understand the power chart which we use in our advertising and to make use of intelligent selling talk based thereon.
The charts we use are mechanically accurate.
The comparison is between a four-cylinder and a six-cylinder of equal total horse-power.
That’s materially different from equal-sized cylinders.
With equal-sized cylinders the four would have 50 per cent less power than the six, and such a comparison would be unfair to the four.
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With equal total horse-power, the only fair basis of comparison, the power in the four mounts higher on each power-stroke. Thus in the chart, four power reaches to the top limit of the chart, whereas six power does not.
That’s a point of advantage for you to emphasize.
That’s where the hammer-blow of the piston comes in. •
On a four of 48 horse-power each piston on the power-stroke strikes a hammer-blow of 7200 pounds.
On a six of 48 horse-power each piston on the power-stroke strikes a hammer-blow of but 4800 pounds.
Therefore, the hammer-blow of the four is 50 per cent heavier.
^
It is an advantage to have as much power as possible in a car (within reasonable limits of course) and it is equally advantageous to have hammer-blows as light as possible. Quantity of power and minimized hammer-blows can be secured only by having six cylinders.
This is true, because more than six cylinders are practically impossible.
It is desirable to have light hammer-blows because the harder each hammer-blow the more quickly is the motor “hammered” into the repair shop.
That proposition needs no further elucidation.
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Note in the charts that the average power in the four and the six is the same.
That is because the total horse-power is equal.
With total horse-power equal, average power must of necessity be equal.
* * *
Now as to actual pressure.
This is represented in both charts by the heavy black line which travels uphill and down over the shaded parts, which represent power.
Note that in the four this line of actual pressure (which means actual driving pressure exerted on the crank shaft and transmitted to the road wheels) falls
The Application of Power in the Six-Cylinder Motor
The Application of Power in the Four-Cylinder Motor
POWER