1. Horsepower What it is and how it works.
Welding and Small Gas Engines

2. The History of Horsepower
The term was invented by James Watt in the 1700’s.
He wanted to be able to talk about the power developed by horses used in coal mines.
He determined that the average horse could complete 33,000 ft-lbs.. Of work in one minute.

3. The History of Horsepower
This unit of measure is still used today for cars, lawnmowers, and vacuums.
To further explain HP, a horse exerting one HP can raise 330 lbs. of coal 100 ft in a minute.

4. Measuring Horsepower
You can measure horsepower by using a dynamometer.
This machine places a load on an engine at different RPMs and measures torque which is converted to HP.
The formula = Torque*RPM’s/5252

5. Measuring Horsepower
The following graph is an example of a typical horsepower curve of an automobile.

6. Measuring Horsepower
What can be learned from these graphs?
It shows peak horsepower at specific RPMs as well as torque.
Example RPM
290 ft-lbs RPM
these figures are for the 1999 Shelby Series 1.
To be first off the line at a stop light, rev your engine to the RPMs for maximum HP and dump the clutch.

7. How to increase Horsepower
Change your computer chip
Increase air flow- bigger air filters, blowers
Increase exhaust flow- bigger pipes, mufflers, headers
Change heads and cams- 4 valve heads improve intake and exhaust flow
Add turbo and or super chargers

8. How to increase Horsepower
Cool the incoming air- the hotter the air, the less it will expand when combustion takes place
Make everything lighter- aluminum is a popular material
Increase the compression ratio
Increase displacement- cubic inches V-6 vs. V-8

9. References