Noise management: Demonstration engine

This publication is for: 
Employee / workerEmployer

Demonstration engines used in training situations consist of an automobile engine mounted in a frame complete with an ignition system, fuel lines, radiator and associated piping, exhaust system and auto electrics required to run the unit. Noise levels in excess of 95 dB(A) can be produced from this source depending on the type of muffler used. Hearing protection is required when test running the engine.


  • Maintain engine in good operational condition, by checking the following components:
    • Valve/rocker tappet clearances.
    • Big end and main bearing wear and correct oil grades. Manifold gasket leaks.
    • Exhaust flange leaks.
    • Holed muffler.
    • Water pump and generator noise.
  • Check frame mounts and instrument panels for vibration and tighten loose parts if necessary. If unit is mobile, fit rubber pads to ends of legs.
  • Ensure that engine can run smoothly at lower revs.

Noise control

  • Fit high performance mufflers (maximum noise attenuation) to engines.
  • Exhaust to an outside area via ducted exhaust outlets.
  • Run demonstration engines outside, if weather conditions permit.

Operator control

  • Avoid revving up motor for long periods of time.
  • Tune for quiet smooth running. 


  • Minimise lengthy use of engine.
  • Make policy of only running engines with mufflers fitted.
  • Where practicable use engines fitted in an old car body. This helps reduce the noise hazard radius and represents the real life situation.

Adapted from the Noise Control Manual for Schools with the permission of the Education Department of Western Australia.


Fact sheet
Last updated 14 May 2014

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