The engine overhaul

[Gary0747]

Yes, I am aware of the mechanism of how the valve opening will be degraded as the cam wears.  In fact Lycoming has a Service Bulletin on how to measure the reduced cam lift. I dont think many actually do it?  My question was asking if anybody had personal experience in seeing degradation in flying performance before they discovered the cam problem in via oil or filter analysis?

[N201MKTurbo]

29 minutes ago, Gary0747 said:

Yes, I am aware of the mechanism of how the valve opening will be degraded as the cam wears.  In fact Lycoming has a Service Bulletin on how to measure the reduced cam lift. I dont think many actually do it?  My question was asking if anybody had personal experience in seeing degradation in flying performance before they discovered the cam problem in via oil or filter analysis?

When I bought my first Mooney (F) in 84 it turned out to have a warn out cam. Half the tappets were severely spalled and two of the cam lobes were considerably worn along with their tappets. 

The engine ran just fine and the plane made good speeds. 

[Hank]

18 minutes ago, N201MKTurbo said:

When I bought my first Mooney (F) in 84 it turned out to have a warn out cam. Half the tappets were severely spalled and two of the cam lobes were considerably worn along with their tappets. 

The engine ran just fine and the plane made good speeds. 

How well did it climb?

[carusoam]

Measuring the valve lift is pretty straight forward.  Few people would do it normally, if they weren't already looking for something...

One challenge I see...

The amount of power and performance variation due to temperature and GTOW.  It would be challenging to notice a decline in power without directly comparing to book numbers adjusted for weight and outside air temp.

With all the portable ADSB devices delivering WAAS accuracy to an app like CloudAhoy... you can collect T/O distance and climb rate pretty accurately... compare to book values...

If you fly with Flight Following, Compare your climb rate that flight aware post for you....

The VSI is pretty good in smooth air.  Check the performance charts in the POH to set up a comparable flight....

Climb rate and T/O distance are direct functions of HP.

To Compare your HP to the book, set up a climb following their guidance...  FT, degrees ROP, IAS, that kind of thing...

Time frame... when a cam lobe is getting eroded... the hardened surface goes away slowly. That may give a year to show up in oil analysis.  When the hardened surface is gone a lot of metal is being removed. The oil analysis goes from parts per million to tea spoons

key words are something like elevated metal ppms in the oil analysis.  Bad news coming, long before being noticeable to the seat of the pants instrumentation. WAAS measurement of climb rate will probably be in between.

Another variable would be engine timing. As HP will be related to the mag timing which might get out of spec. Timing the mag is done normally at annual....

Did I get closer to answering the question? 

Best regards,

-a-

[N201MKTurbo]

10 hours ago, Hank said:

How well did it climb?

I don't remember it being an issue. But it was a long time ago. 

I took the engine apart because it lost oil pressure. One of the gear mounts in the accessory case came loose and was bleeding oil. It tore up the crankcase. I rebuilt that engine myself (showed my mechanic how to do it). Actually I just took it apart, sent all the parts out painted it and put it back together. It was the best engine I had.

[cliffy]

That's exactly what happened to mine. One of the gear drive spuds loosened and I lost oil pressure and have flakes in the filter. Another take off and it too would have lunched the rear case. Mine were held in with the original 1/4 - 20 bolts. I did the 5/16-18 SB. I too did my own overhaul. 1100 hrs and still going strong with no issues. Filter clean as a whistle every oil change. We do @100 hr/yr.

[ragedracer1977]

On 12/17/2017 at 10:30 AM, N201MKTurbo said:

But it will get you by till the next annual. That's assuming this airplane gets annuals.

If memory serves, those guys were hunting the Alaska backcountry.  Left something in the plane and a bear decided he wanted it.  Tore the hell out of it and they were able to patch it up with duct tape to get out and home.

 

edit.  Yup.  Damage was way worse than I remembered.  Bear even ate the tires!  http://www.viralforest.com/this-pilots-airplane-was-attacked-by-a-bear-but-he-repaired-the-whole-thing-with-duct-tape/

Edited January 14, 2018 by ragedracer1977

[Guitarmaster]

Wow!!!! Gotta love duct tape!

Sent from my XT1585 using Tapatalk

[Captnmack]

On 12/15/2017 at 7:14 AM, bob865 said:

BMW started out making airplane engines.  They quit around the 1940's for some reason though. 

But a fun fact if you didn't know, the BMW logo is a spinning propeller.  White for the prop and blue for the sky behind.

 

[Raptor05121]

On 12/16/2017 at 7:17 AM, mike_elliott said:

I know of a plane that was flown every week without fail and within a 400 hrs, the lifters and cam were shot. IO360. Perhaps we should look further than corrosion as the only failure cause of "we dont need no steenkin" cam lubrication Lycomings. Corrosion is a convenient whippin' boy, however, and this one lived in Florida too boot, albeit only a few miles from safe Georgia 

Right in my neck of the woods no doubt

On 12/21/2017 at 8:10 PM, gitmo234 said:

Right now I’m running roughly $24k when it’s all said and done. I believe they are those lifters. He gave me the option but said he strongly recommends brand new lifters/followers when the other parts are replaced. I went with his recommendation

$24k for an IO-360? Thats not too bad. I wonder if an O-360 would be a smidge below that 20k mark.

While we're on prices- how much does a 0-time engine translate to increased value on the airframe? I know 50% loss with avionics, is it the same with engines? 12k increase?

Edited January 29, 2018 by Raptor05121

[Browncbr1]

I had a messed up dream last night.  I dreamed that the IA came to me during annual and told me that they have to overhaul my engine because they found metal.  I argued that I just recently cut open a filter and found nothing, so I want to see what they found.   So I watched them put a borescope up through some scat tube and found metal shavings at a junction in the fresh air vent where someone hadn’t cleaned up some trimming at some point.   I jumped up and argued are you serious you want to overhaul this engine because you found metal shavings that aren’t coming from inside the engine?   They just shrugged their shoulders, then I woke up to my daughter asking if she can watch America’s funniest videos at 6am.   What the heck?

[Wayne Cease]

2 hours ago, Raptor05121 said:

Right in my neck of the woods no doubt

$24k for an IO-360? Thats not too bad. I wonder if an O-360 would be a smidge below that 20k mark.

While we're on prices- how much does a 0-time engine translate to increased value on the airframe? I know 50% loss with avionics, is it the same with engines? 12k increase?

What I've read is it is pretty much 100%.  For the engine, but not the rest of the work involved.  Although there is some concern about a recently rebuilt engine, combination of infant mortality and quality of the work (more so for local shop versus big name rebuilder).

 

[Yetti]

As I fly along I wonder how my engine is trying to fling metal off it's parts.   Why I don't have this same thought while driving or riding my motorcycle or driving my tractor or UTV or 4 wheeler.    Those things I just feed batteries to.  Oh and I had to feed a battery to the plane.

[Oldguy]

1 hour ago, Yetti said:

As I fly along I wonder how my engine is trying to fling metal off it's parts.   Why I don't have this same thought while driving or riding my motorcycle or driving my tractor or UTV or 4 wheeler.    Those things I just feed batteries to.  Oh and I had to feed a battery to the plane.

Because most of those things (motorcycle excepted) can just coast over to the side of the road when engine components decide to go in their own direction. Motorcycle can get a bit exciting when a hot metal piece goes through leathers and boots and welds itself to your skin (yes, it can), but usually you can coast to the side and cuss. Planes? So many response options depending on when they decide to spit out parts, we keep running through the "what would I do if..." scenarios to try to keep up with the possibilities.

Or at least my mind goes that way....