This past winter I did some upgrading to the bike and it has been running great with the exception of some engine rattle. Around 2,500 - 3,000 rpm I'm getting a strange rattle noise from the engine. The noise typically only occurs when accelerating or coasting in a specific instance where there is little to no drivetrain load such as coasting down a slight hill. From where I'm sitting I can best describe it as coming from the front cylinder and sound like a pushrod adjusted too short and getting bounced back and forth. I have adjusted the pushrods 3 separate times, removed and inspected the cam plate assembly, removed both rocker covers and checked torque on the valve train assembly and also checked primary chain tension. I even swapped the front lifters with the rears to see if the noise would follow with no luck. Nothing I've done seems to have given me any indication of where or what is causing this engine rattle. I've put roughly 3k miles on it with the noise having only marginally increased until recently where now I would suspect the noise increasing roughly 20-30%. Given its peak riding season I haven't convinced myself to do a full tear down, though I suspect this winter I will be doing exactly that unless I can cure this issue.
Here is a list of everything I did to the bike this previous winter.
95" BB with 10:1 pistons
Ported and rebuilt heads
SE Camplate
Andrews TW37 Cams
Fueling HP+ lifters
Professionally tuned
I've included a video I took while riding to try and capture the noise. The video description has time stamps that will make it easier to hear these "events" instead of having to watch the whole 2 minute video.

 

Loose heat shield, piston slap, loose primary chain. sagging front mount / pipe hitting frame or something similar.

KB pistons hypers?

 

Does it go away, at least partially when fully warmed up?

 

Chain drive or gear cams. I'm assuming chain. Some cams are just noisy in that area but 37's I have installed were quite

Rocker lockers may help. Certainly cheap enough to try

if noise lessens or goes away when warmed up, worse when cold, I would be thinking maybe some piston slap.

But actually from your video, check your heat shields and just ride it. I can't hear much anything unusual

 

I've checked just about everything on the exterior of the engine and I don't believe anything is loose or rubbing. I know the video doesn't do a great job with identifying that the noise is internal but I'm confident it is. The pistons are the Hypereutectic's

 

Nope, cold or hot its there

 

They are Chain drive 37's. I did add rocker rockers last year which made a huge improvement which is partially why I'm at ends with this rattle. Went from sewing machine smooth to sounding like a bag of bolts are in the crank. Warmed up or cold it doesn't seem to make any difference.

 

My 2000 flhtpi had a similar "rattle"....turned out to be the fins on the top of the jug, I don't know the correct term for what i'm trying to explain...but at the top of the left jug/cylinder the fins on the top are "bolted "on. Mine were loose, I tightened them and the rattle went away. Hope this helps, Good Luck

 

How many miles on the bike? Kinda sounds like a rod knock. Gone under load but there either off throttle or light load. It's hard to hear but it's there and definitely not good, unfortunately it sounds like more than just a lose heat shield or something along those lines.

 

30K miles. New pistons and wrist pins within the last 2k miles. So if it was rod related id imagine it'd have to be crank end as that wasn't touched.

The cylinder head?