So here's the thing. I've seen this before in pictures of rotaries that had "Detonation" issues. But if I recall It was on the leading side of the rotor face. Not the trailing side as I have here. (I'll do another thread on that here shortly) But this is interesting to me none the less.
What made this dent? This dent is in the three sides of the rotor face. But it decreases in depth and size, as you look at each side. It's not the same on all three sides.
First pic is the deep side.
Second pic is the next side. Not so deep.
Third pic, next side, has slight abnormalities.
Remember, this is the trailing side of the rotor. Pretty much the cooler side of the rotor.
Anyway, have at it rotary guru's. I have my own theories. As Of course ya'all do too. So lets hear it. What caused this?

 

Detonation? My tuner (Steve Kan) posted this up, it is from a poorly tuned engine (not by him) that detonated.

 

Detonation would be good. But on the trailing side of the rotor? @9K

Ok So I'll post up the pics of the rotor face that I consider "Detonation".
The rotors are from the same engine. A 2005 MT.
Now what I consider to be just plain detonation. In the center leading edge of the rotor.

Now this is the "Leading" side or the rotor. The cleaner spots on the outside corners, less carbon, are from the OMP metering oil in that area. The center spot on the leading Apex edge, I would presume to be a "Detonation" area. Signs of it. Now this engine did fail due to detonation. And broke an apex seal on that rotor.
More spices in the mix. I love this stuff.

 

9K. That is on the LEADING side of the rotor face. My scenario is on the TRAILING side of the rotor.

Dun Dun Dun. Dramatic Reverb!!!!

 

Running from the law in reverse gear ...................

 

No thats how you lower the compression on a rotor, lol.

Subbed for intrest.

 

A backfire from a misfiring leading plug?

 

Bump.

 

Possible that the tune had too large of a split in timing between leading/trailing? trailing side fired far after the leading side powered the rotation?

 

I actually seen one of the blown engine here that looks exactly like that ---- left a dent at the trailing spot.

I have no idea what the owner did, he said he was pushing it then boom. pretty much stock car.