Have you considered a connecting rod, soft sound on start up and it get louder as the motor warms up.

 

Right now it is all speculation and it could be a number of things. Of course, I am keeping my fingers crossed that it will be something like the cams, and not some other catastrophic event which will require a whole engine breakdown. Until my mechanic opens it up, I won't know what broke. I do have a stethoscope and tried to isolate the noise, but was not able to. I thought initially it was the rocker arm assembly, but that was ruled out when I inspected them. It is also not the tappets or push rods, since I replaced them with S&S pieces. Also, no debris came out during the oil change.

 

Diagnosing motor noises is hard enough when standing next to the source and even harder from a recording; the source could be any number of things. The OP didn't reveal mileage or when the noise first presented which might help narrow down the source. Having said that, the noise sounds like valve train noise to me. Just because new S&S hardware was installed does not rule out lifter weakness or pushrods not adjusted properly. Certainly could be cams, failed tensioner or crank related, so I guess we will have to wait for the diagnosis.

 

I stopped by the shop this afternoon. The mechanic had removed the cam cover, which revealed a newer Screaming Eagle cam plate and outer hydraulic tensioner. I did not expect that. Best of all, not a single sign of deterioration of the cam shoe. Cam chain looked good. He has not taken off the cam plate, but I expect that it might also have a newer style oil pump to match the cam plate, and possibly newer cams. I bought this bike a year ago, so I don't know all that has been done to it. I do know that in 2018 it had work done, including a dyno tune (at 38500 miles. It now has 39,488 miles) and CNC ported Screaming Eagle heads installed. He will need to remove the cams to see further. He also pointed out the inside the rear exhaust port, which looked a bit oily. He said he will need to remove the heads to make sure there was no piston slap of the valves or a bent valve. We shall see.

 

Update: Cam support plate was removed. It had an upgraded cam and oil pump. Bad news: Crankshaft runout was out of specs. Witness marks were found on the cam plate copper ring indicating the crankshaft was bouncing around. Score marks on the cam plate ring were minor, but visible. The rear piston exhaust valve sleeve/guide and seal had come loose and were at the top of the valve stem instead of in place. Still, no signs of what made the noise. Entire engine will have to be torn down.

 

Sorry to hear that. I think we all were hoping for something less drastic.

good luck,
Paul

 

Rear valve guide was loose? There is your noise.

 

Agree with Max. Just lucky the valve didn't snap loose. Much damage then.

 

If it is the valve guide, is that a common occurrence? Might have to replace all guides just in case. Hopefully it did not bend the valve stem. I imagine replacing the guide would still require removal of the heads, but not the entire removal of the engine, I hope.

 

You have to pull the heads. The issue is not real common but does occur. You'll likely need to replace the valve and depending on the damage it might be more convenient to replace the head. Best to take to machine shop that can do the work. Depending on the miles you may want to do a complete valve job / top end while you are in there.