So there I was inverted... No lie, I was really inverted. At the annual I had to replace the #2 cylinder, it had been creeping down on the pressure differential test the last three years. This year it was below 60 and combined with the trend, it was time. Got a manufactured jug and my mechanic put it on. I have been babying the engine. Flying XC . The only time I reduced power was on final to land. After 12-13 hours I decided to do some acro. The last contest of the season is coming up (Nov 2-4 Sebring, FL... Show up, should be a blast). This was going to be my first dedicated acro flight since my last contest and my first sequence since May. I dove into the box and hit my entry speed (160MPH) for my first figure, a loop with a two point roll on top, I start my pull into the loop at 2500 feet, and as I pitch to vertical, I add the remaining power and about 1/4 to 1/3 through the loop BAMN! The engine starts to lose RPM's and I can feel the airspeed dropping and the plane starts to shake. I instinctively pull the power to idle but I am now inverted with my engine trying to shake itself off the mount. I am looking for fire, or smoke... I see none. Luckily, I am pointed at the airport. So I roll upright and start making a beeline for the runway. I glance at my oil pressure and it was in the green... I honestly have no idea what it read, I just glanced at it and it was showing green. I make a radio call: "XXX Traffic, Blue Pitts, I have an emergency, engine issue, I need the runway." The skydiving plane is almost about to land and goes around to give me the airport (thanks Jim). There is no other traffic that has been speaking the last few mins or that responds to my call. I try to move the throttle up a bit to see if I have anything... Yeah it didn't like that and felt like it was going to shake so bad the engine would leave the plane. I thought about killing the power by hitting the mags, but honestly I just didn't feel comfortable killing it and KNOWING I was dead stick.... Don't get me wrong, I could not go around, but I felt better thinking it was a possibility or that I might have enough power to fix a bounce even if I was just lying to myself. And I knew I was lying to myself, there would be no go around. I check the oil pressure, still green and check for smoke or fire... All is as good as can be expected. I enter a tight and high down wind for 13 and make a call, "XXX Blue Pitts, engine out, downwind, high and tight 13, XXX." At this point the jump pilot asks me if I need help.... I really appreciate the offer, but I am ******* deep in the proverbial swamp and trying to drain the water. I reply, "No, can't talk, I'll reply if I don't crash." For some reason, I reach down and check the fuel selector... I had been flying for 10-15 mins, but I just felt like I should check it... It is on my "A" tank where it should be. At this point I consider killing the engine again... To save it. That thought lasts about 1 second - screw the engine. I am at 1K feet and almost at the end of the runway. I crank the plane around knowing I have 5K feet and a draggy biplane. I dive for the numbers... Maybe not the best idea as I see my airspeed blast to 140. I round out at about 10 feet and put the plane into a FWD slip.. Kind of a knife edge just to kill my speed, it works. I get down around 100MPH and roll out to normal landing attitude. I touch down and as soon as I am sure it is not going to bounce, I kill the mags, then the mixture and finally the master. I am rolling down the runway and don't want to foul the only runway with the jump plane waiting, so I brake and turn off on the taxiway about 1800 feet down the runway. Mags checked off, mixture full lean checked, master checked off, then I flip the master back on and inform the airport that I am clear of the runway and I am flipping off the seat belts and getting ready to get the heck out of the plane while checking for fire. At this point, I see the skydiving center's golf cart rolling towards me... And I then remember that my wife was watching the box and was on radio the whole time. We all push the plane back to my hangar. My wife and a buddy tell me that they were watching my flight and when I aborted after the first half loop they were like, "WTH, its over?" Then when they heard "emergency" on the radio and could hear my engine sputtering. They both thought it had died. When I did my base to final, my wife started chanting... "pull up, pull up. pull up". She is also a jumper so does not panic... But she was concerned when I dove at the ground. She did turn to my buddy and ask if she should be filming this, but before she could even start, I was on the ground. After a brief cool down period I called my mechanic. I flip past the first compression stroke and before I can get to the 2nd... The prop hits a wall. He tells me to pull a plug from each cylinder and look inside. I pull the cowl and remove a plug from #1 and find a piece of aluminum sitting right on the plug. I think... Well here it is. I then pull the #3 and then start on the #2..... It is like the plug is GLUED in. I have to crank on it and as the plug comes out, it looks like someone hit it with a hammer. The picture is showing metal almost covering the plug hole. I take a borescope and start looking inside the #2... I really can't tell anything, but it looks like a grenade has gone off inside there. But I am not a mechanic. The other cylinders look OK. Going to have my mechanic look at it when he has time. But my acro season is over and I am going to miss the last contest of the year.