Engine knock audio/video clips

[dan filipi]

I'm putting together all the video's we have of the notorious "knock" to post in a new thread for the Video forum.

Please link to yours so I can download them.

 

[mcgovern61]

 

[dan filipi]

As I rode down our alley it occurred to me sound bounces off the block wall pretty good so I got a new video of the knock while sitting right next to it.

I'm on a mission to solve this mystery and won't stop until I do, or I die first.

The knock is really evident at 1:05 and 1:09

[flv]https://classicgoldwings.com/forum/vids/MyKnockVid_7-22-11.flv[/flv]

 

[mcgovern61]

That noise is deeper and duller than mine!

 

[mcgovern61]

Listening to your video in the gorilla thread, I stick with my last post that your knock is deeper than mine. Now that the heads, valves and springs can be ruled out, it is pointing to pistons, cylinders and bearings. With that start up bell ringing, I am under the opinion that it is piston related.

For my '81 engine, I think the valves, springs and heads would have done the trick...except when you listen to my original noisy start up video which clearly points to loose items getting filled with oil before that initial noise clears.

So, my question is, should we list the different knocks?

 

[dan filipi]

Gerry I think you really need to split that engine open and have a look at it. :beg:

Measure everything, look at the bearings, skirts etc. I'm kind of needing some encouragement.
Although the top end does sound good now, it was disappointing to find I can hear the knock more clearly since it's quieter.

 

[mcgovern61]

If I had to guess, your knock is #1 piston based on the pictures. (It looked like it was sitting lower in the cylinder than the other three, plus there were scores in the bottom of the cylinder consistent with the piston riding low). I wish I had the time (and the room) to split the case, but I am going to be out of town a lot through August. It is my intention to open it up at some point. I do know my top end was fairly shot just based on the valve and spring conditions. I think it fair to say that based on the startup noise, there are loose bearings that quiet down when oiled, but noisy when dry.