Detonation Cans (det cans) to detect engine pinging

[antmanbee]

I was wondering if anyone here has used or made a Det Can?
There is a fair amount of information on the internet about them although it mostly automotive.
They seem like an invaluable tool for getting ignition timing dialed in.
I will be looking to make my own and utilize it in further testing on my Cal Vin ECU map.
It is possible to build either a analog/mechanical one or and electronic one. I am interested in possibly using an old android phone to record and analyze for pinging.
Please let me know if you have any experience with these or any ideas.

Thanks,
antmanbee   

[Sasquatch Jim]

  Amazon has a number of mechanics' stethascopes that can be used fo that purpose.  Prices are reasonable.
 You could even hook up to a set of acoustic ear muffs to minimize other noise while listening to the ping.
 click here

 https://www.amazon.com/s/?ie=UTF8&keywords=mechanical+stethoscope&tag=googhydr-20&index=aps&hvadid=94606681466&hvpos=1o1&hvexid=&hvnetw=g&hvrand=4433036275100289646&hvpone=&hvptwo=&hvqmt=b&hvdev=c&ref=pd_sl_8qbfdx1vyd_b_p10

[guzzisteve]

You should be able to see spots on your spark plugs even if you can't hear it ping. It's a lost art, reading spark plugs. Sometimes it costs a few bucks for new ones to read but still better than the funnypapers.

[Triple Jim]

I hadn't heard the term "Deto cans" before, but did a little reading.  It's a neat idea, and as opposed to reading plugs, can very simply give you real time information about detonation.

Interestingly, I've been toying with the idea of detonation sensors to give the computer in my Guzzi CDI unit the ability to modify the advance curve adaptively, like the way automobiles now do.  Providing the most advance short of pinging throughout the rpm range would maximize fuel economy and power.

[JayDee24ca]

A few years ago my wife bought me one of those ten dollar TV hearing aids that you wear around your neck. A real piece of junk, but her intentions were good. anyway, I took apart the guts, added some longer leads, and turned it into a listening device for detonation and for setting the kick-down linkage on the transmission of my car. Works great. And cheap, which is typical for me.
JD

[atavar]

My hearing aids have a remote control that has a microphone that can stream to the hearing aids.  The intention is that you can set the remote by a TV set or the speaker in a meeting and get good audio in a noisy room.  I find it is great for finding sneaky noises on the bike and the car.  I have even taped it in wheel wells while driving around to pinpoint an annoying squeak. 
If you are an old codger like me you may already have this tool and just not thought about it.

[antmanbee]

My latest thought to what I may make and do is to use an android phone with a mic and attach the mike to a clip of some sort and then wrap it in foam to keep the wind noise down during testing.
I will then import the audio file into my desktop computer and use Audacity program to filter out low and high frequencies that are not needed and I can then analyze it and compare to other recordings on the internet to see what extent I have pinging and under what circumstances.