Me off all people...Cam and lifter failure

[aaronk25]

Dropped off for annual and pulled the #4 cylinder because I was sick of dumping a qt every 2.5 hours though that cylinder. Oil control ring issue.

I took a look at the cam and lifters as long as the cylinder was off and discovered a spalled lifter.

Engine time at prop strike was about 1200 hours so I instructed Willmar to let me know if the engine shop found anything worn and if so to call me because I'd want it fixed. Well engine was inspected and came back to Willmar, without a call.

When it got back I was told the engine got new cam and lifters which the log entry reflected, except I never noticed the "r" after the lifter part number, unfortunately tell now.

They put in reground lifters!!!!! The cam and lifters were installed 2.5 years ago as part of my prop strike inspection of which Willmar Air administered just another thing Willmar screwed up!

In the 2.5 years since the cam and lifters were installed the plane had been flown every 3-5 days with camguard and either 20w-50w Phillips or 50w aeroshell, depending on season. In addition the only time the plane sat for 1-2weeks was during annual and I changed the oil immediately before (with camguard, as always) then flown for a hour to burn of moisture and re-coat all surfaces with new oil.

Goes to show that if a part such as a lifter, is crap, there is no TLC that's going to keep it from failing.

I'm currently evaluating options and may trade in my a3bcd engine fore a re-man lycoming roller cam for $32,200.

This option makes me nervous because another Mooneyspace member did the same thing and the oil analysis has consistently has been 200ppm steel.....and they don't want to stand behind it.

What does a guy do???

[Cruiser]

Hmmmmm, Camguard didn't protect your cam? Maybe they should change the name.

[scottfromiowa]

Really sorry to hear this news Aaron....Keep me posted. Hang in there,

Scott

[scottfromiowa]

Hmmmmm, Camguard didn't protect your cam? Maybe they should change the name.

To DICK...How about DICK, Dick.

[aaronk25]

I don't think it was a camguard failure. Called and left a message for Ed, at Camguard and he called me back within the hour.

I'm confident it was a bad part......but wow I was impressed how clean and deposit free the rings, piston pins, case and valve were!

No idea how or why reground were put in and why I wasn't called and given the option....par for the course I guess.....

[N33GG]

Hate to ask, but were you running LOP, or ROP?

 

Sorry, had to ask...

[scottfromiowa]

Hits just keep coming....

[DaV8or]

I'm so sorry to hear this. It seems we are all just spinning the cylinder and putting the gun to our heads at every annual, or even oil change. It could be any of us at any time I guess. I am curious if you happen to have pictures and also how can you be certain the reground lifter is to blame? Does it look as though the lifter went and then damaged the cam? It does seem as though you did everything right, particularly by flying frequently. Makes me kind of scared because I really don't fly as frequent as you.

 

I haven't heard any bad news about the roller cam engines. What is the beef? They seem like the way to go if you have the dough.

[Danb]

Dave you just gave me that sinking feeling..My plane is now in annual..I mentioned to Dorn everything seems to be working great no squaks..don't mess up my plane....

[scottfromiowa]

engine time now?

[Marauder]

Dave you just gave me that sinking feeling..My plane is now in annual..I mentioned to Dorn everything seems to be working great no squaks..don't mess up my plane....

Want me to check up on your Mooney tomorrow? I'll be over at the avionics shop.

Sent from my iPad using Tapatalk

[kmyfm20s]

Was it actually Willmar that did the tear down and inspection or did they send it off? They should have discussed options or put you in touch with the engine shop. Bummer!

[aaronk25]

Was it actually Willmar that did the tear down and inspection or did they send it off? They should have discussed options or put you in touch with the engine shop. Bummer!

Willmar sent it to the engine shop and they handled all communication with the shop with the understanding to contact me if any parts in the case were suspect. I never got a call and was a bit disappointed that I wasn't told the engine got a cam and lifters until after the engine was reinstalled on the plane. On second thought I thought "hey my prop strike saved me a bunch of money as I just bought this plane and didn't know the cam and lifters were gonna fail." So I didn't say much, because I was told and the logs even read "new lycoming camshaft part number xxxxx, lifter part number xxxxxr (notice the "r" for reground."

So I assumed it was all new parts, as I was told, but the fault lies in the comma which creates a break and means the "new" part status doesn't carry on throughout the sentence.

I'll post a picture tomorrow of the log and bill of sale.

I'd have thought I should have gotten a yellow tag right???

[jetdriven]

Our engine had reground lifters and a new cam as well. At 1200 hours it spalled 3 lifters. I'm convinced the metallurgy in the ~1995 and newer lifters is crap. Combined with the fact the lifters are nitirided. Then they regrind the lifters to the correct dimension but the re-nitriding process won't penetrate the old nitriding or penetrate as well as the factory process we have a setup for what happens here. I'll email more info, but the evidence points to reground lifters as an almost certain incidence as a part that will not make TBO.

Funny thing is Brian knows better. He had 3 teardowns on his J model in 1000 hours due to cam and lifter failure.

[N201MKTurbo]

The problem I've found with reground cams and lifters is the valve lash. You cannot use the same pushrods you had before. The clearance at the rocker arm needs to be between 0.020 and 0.080 with dry lifters. If it is outside that range the lifters won't work right. One of two things will happen and both are bad. If they are too tight the valves won't close and will burn. If it is too loose the lifter will come off the cam and then crash back down. This will force the lifter through the oil film and you will get a moment of metal to metal contact. This is what causes spalling.

[Gmerrell]

Camshafts and lifters are not nitrided in most aircraft engines. Lycoming camshafts are carburized and the lifters are chilled iron.

The latest Lycoming lifters are hardened tool steel with a DLC coating.

Properly reground lifters are as good and possible better than new lifters. It is no coincidence that the lifter that failed was associated with the cylinder that was using excessive oil. The cam and lifter are bathed in hot corrosive blow by gases when the ring seal is compromised.

Dry tappet clearance is very important and should be check at assembly time. Properly reground lifters are machined very little.

.001-.003 material removal is typical. The dry tappet clearance is effected by other factors such as valve seat grinding depth,crankcase machining,camshaft base circle size.There are many factors that can stack up to effect dry tappet clearance that are way more excessive than reground tappets.

Properly reground lifters should meet the new tolerance dimensions of the original manufactured part.

[chrisk]

I can understand the frustration.  How many hours are on the engine since this work?  I'd be pretty unhappy.

[aaronk25]

About 500 hours in 2.5 years....never sat. Always dumped oil as soon as it started looking slightly dirty.

Can't tell you how many times I drove to the airport to go fly for 40 mins or more just to "oil the cam".

[mike_elliott]

I don't think it was a camguard failure. Called and left a message for Ed, at Camguard and he called me back within the hour.

I'm confident it was a bad part......but wow I was impressed how clean and deposit free the rings, piston pins, case and valve were!

No idea how or why reground were put in and why I wasn't called and given the option....par for the course I guess.....

 

Sorry to hear this Aaron. It does sound like another "certified" POS part that seems to invade Lycoming engines. Darn shame you cant blame it on being a Florida plane

You might consider  the route Scott Sellmeyer went vs the roller cam engine. 2 different ways to resolve the obvious engineering issue with the cam/lifter lubrication on the 360 series,  and one hasn't had very good pireps after the big bucks were spent. So glad it held in there until after the wedding trip for you. Be careful how you present this to your bride!

[scottfromiowa]

So 1700 since Major?

[N33GG]

I think the short answer, especially with aircraft engines, there are no guarantees. 

 

Sure, you can do all the things everybody talks about, but a part of the equation, and not an insignificant variable IMHO, boils down to luck and rolling the dice.

 

Sorry you are having the bad luck on this one!

[fantom]

Damn poor break, Aaron.

 

There but for the grace of God, go ALL of us! 

[Alan Fox]

Some have failed form the factory for the last 50 years .......Instead of blaming Wilmar or another shop , sometimes we have to accept the fact that things can and do fail , even if everything is done right......Doesn't make an easy pill to swallow , but new lifters fail just as often as reground.....

[fantom]

Instead of blaming Wilmar or another shop , sometimes we have to accept the fact that things can and do fail , even if everything is done right......

 

Impossible!!!

 

There MUST being someone to sue

[cujet]

Maybe I missed something, but why not simply replace cam, lifters and rings? Then go on your way for the next 1000 hours or so. 

 

I chose a Firewall Forward "drilled camshaft" for my engine. So far, the lobes look great (via borescope up through the oil drain) and no significant iron in the UOA's.