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[sadunbar]

Piston oilers installed and functioning?

[HILLSIDECYCLE.COM]

Heat.
I will also add, that at on time we had a clients bike in here converting it from an 80" Evo to it's current 96" configuration, and that he had used Castrol GTX 20W50 from almost day 1.
The entire of the engine had a dark brown stain throughout.
Did not witness any harm, only the discoloration.
Scott

[Mr. Warlock]

Extreme heat from the detonation is my guess and probably why the molly is gone from the top ring. I think the pistons are fine but I would replace the rings as you will be starting out with fatigued rings.

[HD Street Performance]

Please state your piston to wall clearance and ring end gap clearance.
Sadunbar mentioned oilers, I agree they should be tested or just replaced.

[GMR-PERFORMANCE]

This engine has no miles on it from what I understand it brand new.. A oiler that is not working can cause an issue however I do not believe that they are truly needed at all. Its an added feature, it helps cool the piston but there are so many other engines out there that never had them and they run just fine.

[HD Street Performance]

When they are blocked the piston bottoms get tarnished. The need for oilers I will let others discuss.

[GMR-PERFORMANCE]

Fair enough..

[sadunbar]

When they are blocked the piston bottoms get tarnished. The need for oilers I will let others discuss.

 

The purpose of oilers is to cool the bottom of the piston.  When they become blocked, the piston bottoms become tarnished, as Deweysheads stated.  I doubt the cost conscious MOCO bean counters would approve of the cost of the oilers and associated machining if there was no perceived engineering need for them...  

[GMR-PERFORMANCE]

I think it was more of a EPA deal with the ultra lean afr advanced timing and then the need for a oiler was made known.. I had a S&S engine that was brought to me for a rebuild , at some point someone had used RTV to seal up the oilers and they sealed up the feed as well.. Looked like they used the old GMS that stuff is tenacious. But my point being is that the engine had no pistons issues at all, just was a leaking oil.  But anyways I think we all will find out very soon what really went on.

[11 CVO Convertible]

Please state your piston to wall clearance and ring end gap clearance.
Sadunbar mentioned oilers, I agree they should be tested or just replaced.

I don't know. The pistons and cylinders were sent to Hillside to be set at the proper gap and clearance.  I didn't double check the work. I will call and request the cylinder bores be measured before they get bored. If the stock pistons are cast (and i don't know), and the clearances were not opened enough for the forged piston's extra expansion, that would explain the cylinder wall and piston skirt scuffing.  That could also have been the reason the heat was building to cause detonation and not the coatings.

[HD Street Performance]

Stock pistons are 4032 alloy forged.  If the cylinder is bored to true 4" the clearance is built into the piston. The coatings on the skirt can add material and change the sizing requirement. The coating firm dictates the changes, if any. While looking at everything I woud certainly be looking for rings butting and proper clearance plus concentric bores.

[Lever]

here is some info  in regarding forged and cast pistons

[11 CVO Convertible]

Stock pistons are 4032 alloy forged.  If the cylinder is bored to true 4" the clearance is built into the piston. The coatings on the skirt can add material and change the sizing requirement. The coating firm dictates the changes, if any. While looking at everything I woud certainly be looking for rings butting and proper clearance plus concentric bores.

Then the clearances were fine.  I check the end of the rings, but I didn't see anything except where they were filed.  It just sounds like extreme detonation caused a lot of extra heat in the pistons.

[11 CVO Convertible]

I got the heads and cylinders back from Lozano Brothers.  I had to check the deck height, piston to valve clearance, and the squish.  The deck height was dead on at .000" for both front and rear pistons.  The piston to valve clearance (checked at TDC measured from the valve on seat to piston contact) was .380" on the intakes and .408" on the exhaust.  This puts me at .160" TDC clearance on intakes and .207" on the exhaust.  The squish was .033" measured with the clay thickness after it was squished.  All this was measured with the old .027" compressed head gasket.  Now everything has to go back to LBP for final head work to set the compression (right now the chambers are 98cc's).  The cylinders were bored .010" for the Axtel 20° pistons.  LBP said that the existing cylinders had a horrible bore/hone on them.  They said it was way too coarse and was full of high and low spots.  The new bore and hone on the cylinders are like a work of art.  I've never had an engine with this nice of a hone.

Mike said that Hillside did a good jobs with the heads and all they did was remove the coatings....all the coatings.  The valves remained the original size that Hillside installed.  After LBP cut the 20° on the heads and slightly opened up the chambers to match, the heads flowed 326 cfm on their bench.  The low friction coatings were removed from the valve stems and they were concentric again.  Bottom line, it sounds like the coatings screwed everything up.

[Unbalanced]

I got the heads and cylinders back from Lozano Brothers.  I had to check the deck height, piston to valve clearance, and the squish.  The deck height was dead on at .000" for both front and rear pistons.  The piston to valve clearance (checked at TDC measured from the valve on seat to piston contact) was .380" on the intakes and .408" on the exhaust.  This puts me at .160" TDC clearance on intakes and .207" on the exhaust.  The squish was .033" measured with the clay thickness after it was squished.  All this was measured with the old .027" compressed head gasket.  Now everything has to go back to LBP for final head work to set the compression (right now the chambers are 98cc's).  The cylinders were bored .010" for the Axtel 20° pistons.  LBP said that the existing cylinders had a horrible bore/hone on them.  They said it was way too coarse and was full of high and low spots.  The new bore and hone on the cylinders are like a work of art.  I've never had an engine with this nice of a hone.

Mike said that Hillside did a good jobs with the heads and all they did was remove the coatings....all the coatings.  The valves remained the original size that Hillside installed.  After LBP cut the 20° on the heads and slightly opened up the chambers to match, the heads flowed 326 cfm on their bench.  The low friction coatings were removed from the valve stems and they were concentric again.  Bottom line, it sounds like the coatings screwed everything up.

did you measure squish on both sides of the wrist pins, I see you showed one side?

Were the original cylinders bored prior to putting in the build pistons?  You stated the cylinders were rough full of high / low spots.  If so, who did those and is per LSB is the heat to blame for the lows/high spots or is that a workmanship issue?

You stated the heads flowed 326 cfm at what lift .700?