Acceptable vibration level of a car engine , engine components

[Rhyder88]

What is the maximum vibration level that can be accepted in a car engine and the components mounted around the engine. If the maximum level varies depending on the number of cylinders, is there any formula for determining the target natural frequency value ?

 

[rb1957]

for a Rolls Royce or a Chevy or a HUMV (jeep) ? ... the type of vehicle would affect acceptable vibration.

 

[GregLocock]

for durability some accessory manufacturers or OEMs specify a maximum of 5g RMS at the mounting point of the accessory. Since the typical vibration of a 4 cylinder spark ignition engine reaches 20g at full power that puzzles me rather.

Your vibration limits are set by 3 things

1) radiated sound power
2) vibration transmitted to other components such as ancillaries, gearbox, engine mounts for noise problems

3) durability of the engine and ancillaries and other components.

I don't know of any equations that really help.



Cheers

Greg Locock


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