I wanted to get an idea why this happened so i thought i would show some Photos and see what info i can get. Thank you all for having a look.

Without a full tear down it looks like it got very hot and began a melt down. Meaning a lean series of runs. The possibility also exists that a bearing could have also let go prior to the piston/ring problen, causing a piece of the bearing to slide up the side of the piston and initiating the problem, but the melted condition of the piston leans more towards either too little oil, too lean a mixture setting for prolonged periods of time, or both. The amount of oil sludge pretty much lowers the chance of too little oil to almost zero.

That's the way I see it, but others may have a significantly different view.

I dont think that it was lean if you look at the left side of the exhaust port the piston is in mint shape. Ive circled a spot in one of the pics to help make my point If it was lean the whole piston would show this and not just the spot that failed. this failed at a high rpm so a fair amount of gasses went through this whole. I was thinking that the ring just failed and once that hapened the gasses supper heated the spot where the ring let go the slice in the side of the piston is cut clean almost machined in one of the pics you can see a piece of the piston skirt that just got pealed back as the piece of ring let go and took the piston skirt out. the engine has 6 or 7 gal through it. and has been a solid performer. Im not 100% posative what causes this type of failure and thats why I asked these questions. Im the guy at the field every one askes to help them tune there engine and have seen lots of things go wrong. somehow the ring hit the lip of the exhaust port and poof. It will be sent off to the distributor in the morning and im sure they will have plenty to say Ill post there findings when I get them.

What oil was used? What was the mix ratio? What brand was the engine?

Those answers might help us with an answer.

Elson

Oops, it’s been run lean.

Bill

Oil was Amsoil dominatot Ratio was 40 to 1 I had used 32 to 1 to break it in I also ussed the oil providded by the manufacturer to break it in. The name of the engine manufacturer I want to keep to myself This post isnt to flaim any one or any product Its a damn good engine.

I thought about It being to lean and to be honest I just got the engine to stop burbling in the mid range and was very happy with it but it was still making a mess on the bottom of the plane. It also would flood out a little if i wasnt carefull when starting after the first run of the day. It never sagged on throttle up or after a long upline run.

I have a theory if you look at this photo you can see the dark triangular aera that was one end of the ring tho other end of the ring is square as in the normal end of the ring being that the normal end of the ring was in the exhaust port Im asking myself why this didnt happen on Day one. As Im not allowed to disect this motor and the little brown truck has it we will never know if this is the case. I will let you all know what the service department has to say.

This looks a lot like the brand of engine which I had major cooling problems with when the engine was required to run at full throttle for the entire 30 min flight. I also was using 40:1 amsoil dominator and the issue was not lubrication but heat buildup due to the deficient cooling fin area on the cylinder. Over half of the 13 engines in the research fleet had major component failure ranging from stuck rings to wrist pin bearings. While the engine ran great, component failure from poor cooling fin area caused a brand change. The new brand has aleast 50% more fin area and there were no cooling problems, no component failure after logging a lot of hours in the air (12 different engines)

Elson

Is it one of the engines in your sig?

FWIW It looks to me like a ring "Indexing Pin" failure, allowing the ring gap to rotate into the exhaust port---& as they say "The rest is history"---

Ring indexing pin hmmm now this is something i didnt know. Ive seen this before but didnt know if this engine had one. My engine experiance is more with big diesels. it will be some time next week with any luck before I hear from the shop.

bluemagic98,
Pinning the rings allow bigger ports, with no bridges. It also allows the ring to seat at the same point for better seal.

Dave

I bet Ive seen this in other engines I was just unaware of that being the case with this engine. It sure had plenty of compression.

If it was a pin loss, the question now would be why? Keep us posted on the outcome.

I hate waiting Im a poor guy and this will set me back a long way if they dont cover it. I realy have no business flying these planes but I gota do something.

I wish I had more Info for you But The engine was Replaced No questions asked. Sorry I waited to tell anyone what Engine it was till I got an answer from them as well as there permission to discuse this in an open forum But I felt it was important to give them the opertunity to say yes or no. The Engine was a New Evolution 58 and Horizon service has bent over backwards to get me a replacement There was no question about it Ill see my new engine in a day or 2 It seems they are going to be very serious about giving us Quality service. I told them ide be verry happy to Fly the snots out of the New Engine. I dont think the technition had even disassembled this motor so further Info may not be on its way it was obvious to them it swallowed a ring. Ill be looking over the new engine very carefully. Sorry I dont have more details.

I dont know if horizon looks at these forums but if they do Thank you for your prompt service.

FYI

I am still very impressed with the power of this engine MSE 24-8 6500+ RPM Ive even flown it with a NX 24-10 im guessing at 6300+RPM outstanding when compaired to a 3w75 NX 24-10 6800 RPM im sure these #'s are only a generalization as they are not from the same tach and not on the same day but my ears and seeing both engines in action tell me this is one powerfull motor. Thank you all again for having a look It sure gave me food for thought.

Great!!---It's nice to hear they are going to take care of you & NOT "It's YOUR fault / YOU smoked it"---

I stronly disagree with your attitude towards talking about which engine this was. If there are failures, we need to know about it. A good company will back up thier product, but its always good for us to see what is going wrong to avoid the same fate. Corrupt companies that make bad products count on people like you that will cover up for them. Your attitude creates an environment where corruption and bad products thrive. And the bad companies will obviously never give you permission to talk about it, ( are you a communist ? ) because they love people like you in Cuba and some other places... Its a disservice to us all.

You have to admit waiting for them to make good on something is worth doing and cooler heads make for better judgments. If they hadnt stood behind the engine they would have to return it and then I could disect it myself before making a judgment and a post to RCU. Asking them about it was a jesture of good faith. I wouldnt have kept this to myself forever Just till all the cards where played. the new engine has arived and there are a few changes to the new one. One thing i did know about was the ignition is all new and programable as to what exhaust it has as well as a LED to tell you about battery life and to help you programe the ignition and there is a place to wire in your chike servo and the light helps you setup the throws for the choke as well. There is a automatic shutoff feature that kills the engine if you start it and it runs backwards as well as turning off the ignition if you leave it on. I think the piston is differant there is a dark grey coating on the piston that I dont remember seeing. however I could be wrong there I also see there is a smaller plug with a crushable gasket the older motors plug leaked oil from the engine even though it was very tight im sure there would have been an issue with that over time. After i get a few hours on the new engine I will report back to this post to let everyone know how theis updated Evolution 58 works out. the motor was replaced 1 week to the day from when I shipped it out. Service shipped it out Next day air no charge. Thank you Horizon service.

Im not trying to knock Horizon service, they are the BEST. Horizon has always backed me up 100 % and then some. I order everything from Horizon, dont even look elsewhere, because I know that if there is any kind of problem that they will be there.

JettPilot

I think you're a class act not to mention the engine until it was resolved. Good for you, I wish more like you were outhere.

Roger

Thank you. You have some class acts on your web site as well man if i could afford something like that wow.

http://forgues-research.com evo 456 must be a 4 foot prop on that I see the pilot in the photo he dont look old enough to fly that but i sure bet he wants to.

That thing is HUGE !!! I also looked at the website, very nice... All you had to do was build a seat and belts into that plane and that kid would fit in there just fine Getting permission from your wife to fly your son in an RC plane might be a little more difficult though [:@]

JettPilot

Yes true but I asked permission to just post the picture on my website, since I don't know the people.

Roger