1. Interference & Timing by Erik de Jong

2. Agenda Objective What is Interference What is Engine Timing
Provide a general understanding of engine interference and timing
What is Interference
What is Engine Timing
Effects of Engine Timing
References
Questions

3. Interference
Intake and exhaust valves intersect the path of the piston
Piston rises high enough to hit valves if they are fully extended
Some engines have interference and some don’t
Drawn in picture here

4. Engine Timing
Intake valve opens during first down stroke, closes at bottom.
Exhaust valve opens at bottom of last up stroke, and closes at top
Timing belt driven by drive shaft is connected to cam shaft which controls when valves open and close.
Drawn in picture here

5. Engine Timing Effects If timing is not optimal; Performance is reduced
Efficiency is reduced
Damage to engine could result

6. References www.howstuffworks.com www.google.com (Images)
Rye Zimmerman (Engine Enthusiast)