Motor Car History
 Veteran - Vintage - Classic - Modern
Motor car history
Understanding the Automobile
Toggle Navigation
  • Home
  • Makes and models
  • Motor car History
  • Innovations
  • Trivia
  • Help Guide
  • links
  • You are here:  
  • Motor Car
  • Car Innovation
  • Engine components
  • Valve vacuum delay

Vacuum delay valve

Car Vacuum delay valve explained

 

A vacuum delay valve is a valve with a small orifice, which delays a vacuum signal. These are commonly used in automobiles to alter the behavior of vacuum switches, vacuum motors, and other vacuum devices.

The engine in a common automobile produces almost 20 inches of mercury (68 kPa) of vacuum, and this pressure differential has been utilized for everything from automatic locks and windshield wipers to operating emissions control items.

Engine vacuum is also the best direct source of information on the engine's load.

Most delay valves have a one-way function, where there is either no restriction or no movement in one direction.

Delay valves are usually color-coded to their function.

Color Code Time (seconds) Threshold (+/- seconds) Direction
Orange Black 2 0.5 Forward
Purple Black 4 0.8 Forward
Gray Black 10 2 Forward
Brown Black 20 4 Forward
White Black 63.5 13.5 Forward
Yellow Black 100 20 Forward
Green Black 200 40 Forward
Orange White 2 0.5 Reverse
Purple White 4 0.8 Reverse
Gray White 10 2 Reverse
Gold White 15 3 Reverse
Brown White 20 4 Reverse
Yellow White 100 20 Reverse
Red White 375 75 Reverse

 

Engine components
Return
Valve timing 80 / 89 Valve Variable lift
Send
Print

Related

motor car on you tube

Categories
Engine components

Engines types

  • Petrol Engines
  • Diesel Engines
  • Straight 6 Engines
  • V6 engines
  • V8 Engines
  • Straight-4 Engines
  • Straight-5 Engines

Read more in this section

ignitor Hot tube
ignitor Hot tube
Read more...
Tappet
Tappet
Read more...
Valvetrain
Valvetrain
Read more...

  • You are here:  
  • Motor Car
  • Car Innovation
  • Engine components

Back to Top

© 2021 Motor Car History

X

Right Click

No right click