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How Your Brakes Work

Disc Brake System
- Consists of a brake rotor, which is attached to the wheel, and a caliper, which holds the disc pads. When pressure in applied on the brake pedal, hydraulic pressure from the master cylinder causes a piston in the caliper to force the disc pads to clamp down on the rotor. This creates the friction to slow or stop your vehicle.

Drum Brake System
- Consists of a brake drum attached to the wheel, a wheel cylinder and brake shoes. When pressure is applied on the brake pedal, hydraulic pressure from the master cylinder causes the wheel cylinder to force the brake shoes against the drum. This creates the friction to slow or stop your vehicle.

ABS Brakes
Anti-Lock Brake System are computer-controlled brakes that prevent the wheels from locking up during sudden stops. The system pulses the brakes on and off rapidly to keep the wheels from locking-up and skidding.

Parking Brake System
- Uses cables to mechanically apply the brakes when not being driven.

Master Cylinder

When you apply pressure on the brake pedal, pressure is created in the master cylinder which forces fluid out to the wheels.

Brake Lines & Hoses
Brake fluid travels through steel lines and high-pressure rubber hoses.

Brake Calipers & Wheel Cylinders
Located at each wheel, the pressurized fluid causes these devices to force the friction material against the drum and/or rotor to slow or stop the vehicle.

Engine Calculations
Piston Speed (ft/min.)
a = RPM
b = Stroke of Engine (ft)
Formula: 2 x a x b
Example: 2 x 8000 x .333 = 5328 ft/min

Compression Ratio (Total Swept Volume)
a = Combustion Chamber Volume at TDC
b = Cylinder Displacement (cc)
Formula: (a + b) / a
Example: (100.00 + 823.70) / 100.00 = 9.237

Rod Ratio
a = Rod Length
b = Stroke of Engine
Formula: a / b
Example: 6.0 / 3.5 = 1.714

Rod Length
a = Cylinder Block Length
b = Deck Clearance
c = Target Compression Height of Piston
d = Stroke of Engine
Formula: a - b - (c + (d / 2))
Example: 9.025 - .025 - (1.0 + (3.5 / 2)) = 6.25
Piston Dome Volume
a = Head Chamber Volume (cc)
b = Gasket Volume (cc)
c = Deck to Piston Volume (cc)
d = Cylinder Displacement
e = Target Compression Ratio
Formula: (a + b + c - (d / (e - 1.00))) x -1
Example: (60 + 10 + 10 - (823.7 / (9.237 - 1.00))) x -1 = 20cc

Piston Compression Height
a = Block Length
b = Stroke of Engine
c = Rod Length
d = Deck Clearance
Formula: a - (b / 2 + c) - d
Example: 9.025 - (3.50 / 2 + 6.00) - .025 = 1.250

Cylinder Displacement
a = Bore (Inches)
b = Stroke of Engine (Inches)
c = Number of Cylinders
cc Formula: a x a x .7854 x b x 16.387 x c
cc Example: 4 x 4 x .7854 x 4.0 x 16.387 x 6 = 4942.2142
CI Formula: a x a x .7854 x b x c
CI Example: 4 x 4 x .7854 x 4.0 x 6 = 301.5936

Dynometer is a water engine brake that produces horsepower and torque ratings. The engine connects to and drives a large water pump. The pump is outfitted with a restriction plate. When the engine accelerates, the restriction plate creates a load on the pump. A meter attached to the other side of the pump reads the pressure built up behind the restriction and calculates the amount of torque the engine is producing. The torque figure and rpm are multiplied then divided by 5250. This gives us the horsepower.

Example
427 Lbs TQ times 5,500 RPMS divided by 5250 = 447 horsepower