Loud noise under heavy load

[Bhawkins854]

Having an issue with my 08 s&s 117 making a noise under heavy load as if something is broken.. Very hard to explain the noise but it's coming from the top end. Doesnt make the noise unless until I reach roughly4 grand. It made this noise a few thousand miles ago but was very faint, it has gotten louder now. I have lots of work done, shaved heads jugs, oversized intake valves and comp cams spring etc . I changed out my standard rocker arms for s&s rollers a few months ago as well. In the process I noticed my pushrods were very close to contacting my heads after the jugs/heads were shaves but ddidn't notice any contact makes on the rods. I have good compression readings, could this noise be my rods? Maybe my valves need adjusting? Maybe a ping? The sound is like nothing i have heard before

 

[Bhawkins854]

As you guys know these ssw+ motors have their normal "top end" noise that the motor has made as longas iI've owned it.. My buddy and I set the pushrod timing to 24 turns as it was before the roller rockers were added. So the timing should be right on, maybe someone has ran into issues like this with decked heads, maybe putting tapered rods would help. Best description I can come up with is a scraping noise, almost as if something is broken but I just had the rocker assembly open a few months ago and everything seemed fine!

 

[KaptinAmerika]

Were the heads clayed after the decking to make sure the valves aren't touching the pistons
Top end knock at RPM sounds like valve float and valves contacting pistons.
JohnSachs is an engine builder here on the forum and can probably give you great insight on this

 

[Thumper]

Dont forget the obvious things like a loose upper motor mount

 

[RCAdd1ct]

Dont forget the obvious things like a loose upper motor mount

Or the vent tube

 

[woodbutcher]

Or the vent tube

ask "raywood" about his top end rebuild. :roll::roll::roll::roll:

the thread that just keeps on giving. :roll::roll:

 

[Bhawkins854]

Yes they were clayed a while ago not a ton of clearance but enough.. I've got about 10k miles on this motor build, it has always used a little more oil than i would like but never and funky noises like this. Valve float seems logical I might need to check my adjustment once more. Thing is the motor is still a beast, no misses at all, pulls all the way through the rpm range.

 

[KaptinAmerika]

Is it a "Knock" or a high frequency rattle

 

[claw]

Look for black soot between the fins in the head gasket area. If your gaskets weren't upgraded when the engine work was done, they may have failed. Mine would only let go under hard acceleration at first.

Just a thought.

 

[Bhawkins854]

Its more of a rattle than a knock. Almost a springy type noise.. I would think I'd be getting misfires or engine bog with valve float.

 

[KaptinAmerika]

Check the overflow tube in your tank. It probably broke where it connects at the bottom of the tank.

 

[BigDogBro1]

If you didn't have a lot of valve clearance when the engine was clayed maybe now after everything has worn/seated in, the clearance is now not enough at higher RPM.

 

[Olde Man]

Check the front and rear tank mounts by pushing down and pulling up on the ends to see if it changes the noise. My rear did this when it wore out and my front did this when I installed the bottom bar of the front mount upside down. It let the front of the tank touch the frame when it vibrated.

 

[bigdogtech01]

Just a thought, you might want to call S&S and have them run the numbers off the crank case to see if they originally built the motor, or if BDM did. Being an 08, S&S should have. But, if the bike was built in 07, BDM might have. This being said, I just recently took a motor apart for a customer in Sweden who had his pinion shaft fail due to a loose pinion gear nut. From what it looked like, the motor actually ran out of mechanical time for a few thousand miles before it failed. If the nut is loose on yours as well, it could cause excessive noises at higher RPM's.