Dectecting and recording engine knock. - Dectecting and recording engine knock.

[Jesse Lackman]

Here is a product designed to do this and they have some of the best sound clips of engine knock I have heard;



I'm wondering about building a similar system using contact microphones like these;



They could be potted with high temp epoxy, epoxied to a metal tab bolted to the engine.

The reason contact microphones are appealing is that they might have a greater frequency range than a knock sensor and thus might enable one to hear the onset of mechanical failure.

I am not an electronics person so I don't know how a contact microphone would compare to a knock sensor, nor do I know how to set up amplifying and sensitivity circuits like the Knockbox has.

What is driving this is aother dyno test of cylinder head grooves and checking to see if they decrease engine knock.

Comments?

[gofaster]

I don't know much about the newest trends in automobile sensors, but in motorcycle ignitions, S&S has a Knock sensor that works with their Intelligent Spark Technology Ignition System (IST). It must work great, because they add a year of warranty to their high performance engines if this ignition is spec'ed.