kmyfm20s Posted October 16, 2013 Report Posted October 16, 2013 After 3 oil changes with metal in the filter on my IO-360 A3B6D and the "lets check it every 25 hours and see" advice I was getting I couldn't take it any longer and had to go in for the inspection. I ditched the MSC and got a mechanic that would help me out with an owner assist and so far I'm very pleased with being involved. I was convinced that I had a piston pin retaining plug wearing on the cylinder walls but the borescope showed no such evidence. The 3 oil analysis was indicating an increase in Aluminum and chromium. I was surprised after the 2nd oil analysis I sent in the filter as well and that came back normal with primarily Aluminum. After 82 hours(approximately 12,500,000 revolutions) of flying uncomfortably it was time pull things apart. After opening things up this is what we found! A broken exhaust valve spring on #4. On the onset of the project I decided that I was going to pull all cylinders because of some weeping of oil and a through bolt. If things looked good, which they did, the cylinders where going to be sent to Ly-Con to be Ported and flow balance (they claim 4 to 5 Hp per cylinder and smoother). This engine was an original lower end and only 1450 hours, I was concerned that it would have some evidence of corrosion but the inside was perfect, couldn't have looked any better. So I order a new a new Planes Power alternator, Sky-Tech ultra lightweight starter, vacuum pump, stand by vacuum(precise), some new hardware and all new hoses. I'm planning for TBO and beyond, wish me luck! Karson Quote
rbridges Posted October 16, 2013 Report Posted October 16, 2013 could you get any indication in flight that the spring was broken? Quote
kmyfm20s Posted October 16, 2013 Author Report Posted October 16, 2013 Nope it was running flawless! The compression went up from the annual except the #4 stayed the same at 74/80, the rest 77. The only thing that I noticed at the last few flights was the EGT would disappear on #4 at Idle but still no perceptible roughness or feel in the engine. This was kind of the final push to check the probe or cylinder. Quote
Shadrach Posted October 16, 2013 Report Posted October 16, 2013 I'm surprised that there was no hint of valve float in cruise (low EGT). Do you have a theory about why a broken steel spring was causing aluminum to show up in the oil? Makes me wonder if there's not more to the story.... Quote
KSMooniac Posted October 16, 2013 Report Posted October 16, 2013 I'm surprised that there was no hint of valve float in cruise (low EGT). Do you have a theory about why a broken steel spring was causing aluminum to show up in the oil? Makes me wonder if there's not more to the story.... I'd like to know this as well. You've also given me something to check before I remove my engine... we borescoped my valves on the problematic #4 but they looked exceptionally good, yet I have been having some puzzling issues. Quote
kmyfm20s Posted October 16, 2013 Author Report Posted October 16, 2013 I'm surprised that there was no hint of valve float in cruise (low EGT). Do you have a theory about why a broken steel spring was causing aluminum to show up in the oil? Makes me wonder if there's not more to the story.... If you look closely on the 4th picture you can see where the valve spring was grooving into the head. Also look at the pictures with the valve springs in place, the spring is offset from the retainer and the spring is up against the aluminum. I have a brighter picture that was not as clear that I will show. Quote
kmyfm20s Posted October 16, 2013 Author Report Posted October 16, 2013 A little blurry but you can see 2 shinny grooves in the aluminum. Quote
Shadrach Posted October 16, 2013 Report Posted October 16, 2013 I did not see that, and I was specifically looking for some area that showed scaring in the casting.... Quote
kmyfm20s Posted October 16, 2013 Author Report Posted October 16, 2013 I did not see that, and I was specifically looking for some area that showed scaring in the casting.... Neither did 2 other mechanics, that why I have enjoyed being involved with the owner assist on this one:) Quote
fantom Posted October 16, 2013 Report Posted October 16, 2013 I have a brighter picture that was not as clear that I will show. Thanks for the report and pictures. What the heck is going on around here? Has me thinking about this interesting Mike Busch offering: https://www.savvyanalysis.com/Pro Or buying Snap-On BK8000: http://buy1.snapon.com/catalog/item.asp?P65=&tool=&item_ID=742121&group_ID=682424 Quote
fantom Posted October 16, 2013 Report Posted October 16, 2013 Neither did 2 other mechanics, that why I have enjoyed being involved with the owner assist on this one:) Yep....when it's your butt, love labor is the best way to go! 1 Quote
Shadrach Posted October 16, 2013 Report Posted October 16, 2013 Neither did 2 other mechanics, that why I have enjoyed being involved with the owner assist on this one:) This was my impetus to become "hands on" as well... The more I got into my plane, the more I realized that much of the work that was done over the years was just good enough and some was less than good enough. Knowing what I know now, there were two individuals who worked on my plane over the last 15 years that I'd like to buy for what they're worth and sell for what they think they're worth. One was in avionics and the other an IA. It's one thing to be the kind of cheap ass owner that seeks a pencil whipper for annual inspection. It's quite another to pay for and think you're getting a thorough inspection, only to find out it was pretty much a $1700 oil and filter change. I'm particular about my safety wire, I can tell what's mine over other's. If a mechanic won't be troubled to check a gascolator screen, what else might he omit?... 2 Quote
KSMooniac Posted October 16, 2013 Report Posted October 16, 2013 Thanks for the report and pictures. What the heck is going on around here? Has me thinking about this interesting Mike Busch offering: https://www.savvyanalysis.com/Pro Or buying Snap-On BK8000: http://buy1.snapon.com/catalog/item.asp?P65=&tool=&item_ID=742121&group_ID=682424 Sad that a CHINESE snap-on borescope costs that much... I bet the same thing without a red case can be had for less. I have a fairly handy Whistler unit that is similar, but it uses a 45 deg mirror attachment to see 90 degrees and it is worthless. Straight ahead, it is great, and it was only $115. We used it to check the tail attachment AD a couple years ago and it saved a lot of hassle. It is great for looking at pistons, but not valves. The Beech crowd found some cheap dental intraoral cameras from ebay that view 90 degrees directly and they're supposedly great for valves. My IA got a surplus dental rig with a big box and S-Video output that combines with an image capturing dongle for a laptop PC and takes pictures of valves every annual just to track wear patterns. Very handy. Quote
kmyfm20s Posted October 16, 2013 Author Report Posted October 16, 2013 Sad that a CHINESE snap-on borescope costs that much... I bet the same thing without a red case can be had for less. I have a fairly handy Whistler unit that is similar, but it uses a 45 deg mirror attachment to see 90 degrees and it is worthless. Straight ahead, it is great, and it was only $115. We used it to check the tail attachment AD a couple years ago and it saved a lot of hassle. It is great for looking at pistons, but not valves. The Beech crowd found some cheap dental intraoral cameras from ebay that view 90 degrees directly and they're supposedly great for valves. My IA got a surplus dental rig with a big box and S-Video output that combines with an image capturing dongle for a laptop PC and takes pictures of valves every annual just to track wear patterns. Very handy. Just got mine dental camera in the mail yesterday. I will try to get a PIREP together. Quote
N201MKTurbo Posted October 16, 2013 Report Posted October 16, 2013 I had the exact same problem. My engine ran great with a broken outer valve spring. I took the cylinder to the local engine shop to buy a new valve spring. They were out of stock, but offered me a used spring that they said had less then 100 hours on it. She changed it in less then a minute and wouldn't let me pay for it. There are a lot of good people out there.... Quote
flyboy Posted October 16, 2013 Report Posted October 16, 2013 Thank you for the pirep. Me thinks this would be a good think to take a look at during annual. Quote
kmyfm20s Posted October 16, 2013 Author Report Posted October 16, 2013 I had the exact same problem. My engine ran great with a broken outer valve spring. I took the cylinder to the local engine shop to buy a new valve spring. They were out of stock, but offered me a used spring that they said had less then 100 hours on it. She changed it in less then a minute and wouldn't let me pay for it. There are a lot of good people out there.... Dang.......please tell me she was good looking! Quote
N201MKTurbo Posted October 17, 2013 Report Posted October 17, 2013 Dang.......please tell me she was good looking! She looked like an A&P mechanic... Quote
Jamie Posted October 17, 2013 Report Posted October 17, 2013 She looked like an A&P mechanic... She looked like an A&P mechanic that just did you a solid. That's worth at least +1 or +2 points. Attractivness is often contextual. 3 Quote
1964-M20E Posted October 17, 2013 Report Posted October 17, 2013 My Mechanic is a female and I was just visiting with her today to change the throttle body. Good MX Quote
fantom Posted October 17, 2013 Report Posted October 17, 2013 She looked like an A&P mechanic... UGH Quote
mike_elliott Posted October 17, 2013 Report Posted October 17, 2013 couldn't be any worse than Maxwell in a thong.... Quote
Shadrach Posted October 17, 2013 Report Posted October 17, 2013 couldn't be any worse than Maxwell in a thong.... That's hot... Quote
fantom Posted October 17, 2013 Report Posted October 17, 2013 couldn't be any worse than Maxwell in a thong.... What's this I hear about you and a famous waitress getting together out in Texas, and you not keeping quiet about it Quote
kmyfm20s Posted October 18, 2013 Author Report Posted October 18, 2013 She looked like an A&P mechanic... That wasn't the Snap-On tool poster image I was hoping for with your reply! Then again you might interface with a lot better looking A&P's than we have around here. Quote
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