Looks like the both pistons are hitting the case on the exhaust side.

 

Hi Clammy,

I just finished reassembling everything after splitting the case. Unfortunately the balancers or anything in the case is not the problem. I honestly wish it was as then this could end once the parts are replaced. Everything in the case is smooth as silk and silent as can be. Flywheel, bearings, chain, all of it functioning like new. The sound remains after reassembly. based on the marks on the cylinders, there's no other explanation than faulty piston/cylinder fit even though the measurements are within spec. S&S is trying to blame me for something that would make me responsible buy I have been able to prove every attempt wrong so far. Here are links to the front and rear cylinders when I dismantled the engine a couple days ago:

https://photos.app.goo.gl/zg3EHDuxjJUPYL196

https://photos.app.goo.gl/ztoCqtkBviygG2Xv7

I, going to post this as an update on the main post.

 

Good morning all.

I'm swapping the pistons and cylinders front to back and back to front to see if that makes a difference. Last night when I removed them i noticed that the rear piston exhaust side skirt was wearing away a substantial amount of material from the cylinder. Enough to make a ledge that measures .005. It's circled in yellow in the attached picture. Is there anything I could have done wrong to make the piston move like this in the cylinder and cause the noise and marks? It seems like aside from boring the cylinder myself, there's nothing that could cause this but faulty fitment from the factory.
I sent pics and vids to S&S Cycle and they have had about 10 people within the company look at them but still haven't replied. This is the second cylinder and piston set as they replaced the first for faulty clearance. Looks like it needs to be a third.

 

The piston skirt is seizing in the cylinder. Measure everything and find out why. At this point, you need to replace the piston and the cylinder because all they are is paperweights. If you run them, your engine is going to have piston slap something fierce.

 

Thanks for the input, Tommy C. I'm definitely in complete agreement with you, I'm just waiting for S&S to make it happen. They seem to be debating this as they don't want to warranty a second set. The tech rep started giving me an attitude when I asked a question he didn't like during the build and freaked out that i was keeping him updated on the rebuild after he told me he wanted to be deeply involved in the break in process. I asked about removing material from oversized oil rings that wouldn't fit in the cylinder and I attached pics of the piston circlips installed properly) All of a sudden he sent me an email telling me to have a qualified mechanic do it but in a much more freaked out tone. Since then he has ignored my emails. I was directed to take the cam plate apart for cleaning after a sandblaster disregarded instructions and filled the case with their medium and the tech rep wouldn't tell me how to set the pressure relief valve to factory settings, just if I adjusted it i would void the warranty on everything I purchased of theirs.
So now I'm waiting on their decision regarding the present issue. That's why I asked if it is a fitment issue or can mistakes be made during a build that could cause this type of problem to happen.

 

@davidlyons37 I must be invisible, did you even look at and read post #20 & #21?
Did you mock up the pistons on the rods in a case half and see if everything clears?
You can't bore those cylinders, but you can maybe hone .002" out and use the KB pistons I mentioned
You really need to start over, get all the red paint out and completely clean everything including the oil pan.

 

By the way,i did measure everything. It was all good.

 

Quoted for emphasis.

 

I figured out the problem. Previously i stated that i measured everything and it was all within spec. I was mistaken and basing it on what I knew regarding coated pistons which can run tighter clearances. I'm running uncoated forged s&s pistons which require a minimum of 0025. I have .001 at the bottom of the cylinder and max .002 everywhere else. That explains why it gets worse as it heats up. The piston is expanding faster than the cylinder and causing the problem. Clearly a fitment issue which should be covered by S&S warranty. The last set was opposite with too much clearance and they sent this replacement without any hassle. I guess I'll have to wait until at least Monday to talk with them. What is the consensus on removing .002 from the skirts so I can actually ride this thing? It still gets worse when hot as of today. It seems easier to remove material from the piston at this point than honing the cylinder where I will need to put it back in torque plates to measure each time.

 

The pistons are cam ground so chucking them up in a lathe to remove material from the skirts is not a viable option. If it was mine, I'd disassemble the engine completely and start from scratch, and carefully check all clearances, and remove the red paint from inside the cases.