I had some metal in my filter during a recent oil change. The cause turned out to be pretty easy to find after pulling the valve covers. It turned out 3 of the 6 cylinders had this in them:



I'm not an engine expert, but looks like parts from the intake valve springs. The engine only has 140 hours SMOH. The fact that 50% of the cylinders had the exact same problem leads me to believe parts were put together incorrectly or the wrong parts used. Is there another possibility i should be considering?

A forth cylinder had this problem:



Given the low time and wide spread issues, I've got LOW confidence in this engine and my gut is telling me I should pull it and have the whole thing thoroughly checked. But before I through the baby out with the water I wouldn't mind hearing what others have to say, given the wealth of knowledge on this forum. Thanks.

Looks like my avionics madness thread is going to have to wait a bit after this repair bill

Eric

Wow! Who did the overhaul and what do they have to say?

With that much crap floating around, if it was mine it'd be off the airplane and case split to see what other damage may have been done.

Gump

I'm not a mechanic, but I agree with Gump. I have observed mechanics taking a lot of engines apart and have never seen that kind of damage.

What is the model engine if you don't mind me asking? I would consider the engine dead and a tear down would be the safe thing to do in my opinion. The cylinder head bosses are destroyed which means the cylinder heads are trashed as well, but I would find the root cause of the problem before pursuing the overhaul shop because at 150hr SMOH and 3 faulty cylinders, I would speculate this as an overhaul shop error. Ive seen rocker arms and rocker shafts wear out due to incorrect length pushrods but never seen them crack the bosses before, but an easy way to check this is to measure your rocker lift off the valve stems. Another possibility would be incorrect hydraulic tappets or/and tappets missing pieces when installing into lifter, when installing the cylinders. Ive seen them float and jam against the lifter before causing case cracks/ cylinder head damage but this kind of error usually never gets off the ground. But IMO, I would get an isolated A&P to find the root cause, because I know some shops will attempt to cover up problems like this and blame it to user error resulting in a large price tag for the aircraft owner. Hope it works out for you and good luck.

Pull it and tear it down.... The parts in the valve cover look too small to me to be valve springs... Take pictures of everything you find wrong...

I have never seen a rocker tower break like that... That cylinder is junk IMO...

Brian

If you were nearby here, I'd tell you to take it off and who to take it to. But you need a good independent engine guy (someone with both the certificate credentials and a stellar reputation) to go through it and find out what else is wrong with it--someone who is not only good at engines, but also willing and articulate enough to use as your expert if you have to pursue legal action. Be prepared to spend money to have it examined. Once you find out what is haywire, then you may need a good aviation-oriented attorney to help you go after the rebuilder.

Cary

Wrong valve springs? As mentioned, push rods so long that the lifter is completely collapsing. I had a parallel valve 0-360 once with angle valve springs installed on once cylinder. In that case though it was pulling the valves through the seats in about 75 hours. Took a well seasoned pro to find the problem. Your problem looks way worse. Somebody really screwed up.

Just a stab in the dark here, but that looks more like a 'cir-clip'....'C-clip'...or whatever the local mechanic calls it. Is this type of clip the kind that holds the rocker shafts into the cylinder head? Asking since I have no idea what engine this is on. Having worked on many different types of engines over the years I had seen different types of retaining clips and this almost looks to be that type of item.

As has been said, I think someone really screwed up!!! A friend recently had an O-320 rebuilt by a reputable shop/person. After installation and run up tests there was an obvious noise coming from the engine. Ended up being a nut left in a cylinder!!!! Engine went back to the shop.

the engine is an IO-520D. The rocker pins are bolted in place, so no retainer clip on those. The two pics below are 2 of the 3 intake valves where it looks to me like the inner valve spring has some serious issues. I'm assuming the debris came from there. I've looked at the 520 overhaul manual and I don't see what other part in that area would have that same size/shape, but I don't have a lot of experience with this kind of work.




The engine was overhauled in '09 and put on an experimental. I purchased the plane from the builder a year ago and put the last 40 hours on it. I'm not looking for lawsuits, nor do I think I could if I wanted to. I also want to be clear that I am happy with the transaction I had with the previous owner/builder, the plane is otherwise a fine example of what a kit built should be and do not think he was trying to swindle me. My only concern now is to do whatever is needed to fix it right.

Thanks for the inputs so far

-Eric

Ouch.... Figure top at a minimum, and open it up to inspect and clean up the metal floating around. I was there a few years back and it's amazing the damage that can be done.

On a bright note, at least you'll know exactly where you're starting from with this engine.

Gump

Looks like the springs are binding from being compressed too far.
Maybe wrong springs?
Wrong rockers?
Maybe being as it's experimental someone had the cam ground for a higher lift???

What kind of metal did you find in the filter?
Everything in the rocker cover is probably magnetic , does that match the filter contamination?

I would suspect the valve spring broken parts would have a tough time making it's way back to the sump and through the pickup screen and into the filter.

How do your lifters look?
What about the cam lobes?
Both would be magnetic particles too.

Looking at the IO520 parts manual it looks like it could be part number 628491, ring, retaining which keeps the lifter plunger and socket in the lifter body, It would travel up the push rod tube. May have been damaged if the push rods had been removed and not properly seated in the lifter socket when reassembled. This could also explain the broken lifter boss. You can pull the lifters on the IO520 to check them without removing the cylinder by removing the push rods and push rod tubes. The lifters will just slide out, you can also see the cam lobe. You may have to use a bent scribe to pull the lifter. That's my guess anyway.

Tim

You see that ECI cast into the head? There's your problem! Good luck getting a nickel out of them!
Believe me I feel your pain!

The metal in the filter was an alloy steel. I agree the big pieces wouldn't have made it out of the rocker covers, but there where plenty of small pieces that could have, plus with the moving parts I imagine big pieces were continuously being converted into small ones.

Wow thats not good! I see its on both the intake and exhaust. These things a pretty dang tolerant to push rod lengths. Im sure if you were on either side of the deflated lifter rocker clearance it would not fail like this.
The parts are obviously from the springs seeing the pictures. I cant tell where the o ring debris is from?

My guess is bad springs. Too brittle. When they broke it jammed up the valve and broke the rocker boss. I bet that push rod is bent...
Its 99% of the time the fault of the builder with that low of time but i would place my bet on bad ECI springs.
Tear it down! I know i would never trust a motor again that ate that much steel.

With what I see in the few pictures here I'd pull the motor -put on engine stand and Do teardown inspection by certified shop. This is serious -appears the rocker arm boss is broken . Valve springs are broken and god only knows what else. Think you got a IO-520 D "overhauled " by students or home builders .Need to remove pan and inspect cam up close and personal . I wouldn't fly this until this is resolved.

i would place my bet on bad ECI springs.

I have ECI cylinders and hope this doesn't happen. On my old O 470 A, I did a top and after a couple hundred hours the rocker bushings were about worn through. I figured the rest of the engine must be toast also. When I tore it down, the rocker bushings were all that was wrong and later found out the springs were too strong. When people say ECI or Continental is the problem( I've seen poor quality Continental stuff too), the real problem is America has a workforce that has a bad attitude when they go to work and in this case poured the wrong ingredients in the pot or didn't process the finished spring properly. Maybe should add, I'd tear it down for sure. If you do, I'm curious what the oil pump gears and housing look like.

Would also tear down as I am sure you are going to. Thank Goodness you found it on the ground and not on takeoff! I bet it's not a complete disaster. If your case and crank are still good you are pretty much golden in terms of "real" airplane unit hemorrhage.

Good luck.

I agree with the others time for a complete teardown and rebuild. Scrap all the cylinders!!!!!! If it happened on 3 of them the rest will follow and putting a bad jug on a now motor is a good way to loose more money. Send the cases to Devco to get redone. You don't need a specialty shop for the rebuild just a good case (Devco overhaul) crank and cam. Then find decent shop to do the rebuild. The closer to you the better. It is not hard to put together a motor but if you have the wrong or bad parts it will not last no matter who put it together. Do you have a good shop on your airfield that will stand behind there work?
Denny

Thanks for all the inputs. I talked with my engine shop today and like the unanimous voice on this thread, will be pulling the engine and splitting the case to make sure the core is good. The shop said it is not uncommon for broken valve springs on new cylinders that sit prior to being put into service because the springs get pitted, and then fail at those spots. This engine was overhauled 3 years before the plane got off the ground, so that's conceivable. As far as the broken cylinder, he said it is extremely uncommon to crack there and thinks either part or assembly issue. Either way, we'll get it straightened out and rebuild what's needed.

Would rather spend the money on flying, but better to pay for the maintenance on the ground verse paying for the lack of it in the air...