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Lycoming Cam Issue Poll


INA201

Cam Issues  

76 members have voted

  1. 1. Have you had a cam issue?

    • I have had a cam failure due to corrosion, lobe degradation, or a lifter problem related to the cam.
      25
    • I have never had a cam related problem.
      51


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2 hours ago, Stephen said:

Probably want to poll "Of those that have had your Lycoming rebuilt/directly inspected, how many have exhibited CAM issues/wear etc..." Some of us may cam wear and it isn't caught until it is caught at rebuild time.  

Let’s dont thread drift but I think Champion developed a bad reputation for spark plugs from a certain period in their history too. It is quite possible that most cam problems were due to a particular supplier or metallurgy that was from a distinct time period.  I’ve seen some posts though where folks have recently had a factory reman to only have cam problems soon after. It really is hard to get statistically significant data on a poll like this but does give a decent picture of overall issues or not.   

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I think the poll should have ask which planes were in hangar. Either cars or planes are subject to more corrosion and wearing when left outside. Take a couple of nails and leave some outside and others inside the hangar. In a month you will see how the ones left outside corrode vs the ones in the hangar. Engine cylinders fins will corrode quicker when on the ramp vs the ones inside the hangar. If the planes is left outside it should be flown at least once a week to keep engine oil on the cam, specially in hot weather when oil thins quicker and drip down to the oil sump. When shopping for a used plane look at the engine bolts and cylinders for signs of corrosion. If there is minimal corrosion on the outside there will be some or none inside the engine. Like on boats corrosion always happens first on the outside.

José

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7 hours ago, EricJ said:

Auto manufacturers don't have to go through an expensive certification process every time they change a design.  They are much more able to utilize improvements in metallurgy and design.   Their larger economy of scale doesn't hurt, either.

There isn’t an expensive certification process for this. The roller cam change  was like 3 engines that flew 300-500hr each. The faa agreed, it’s a minor change and they updated the drawings and castings and started making them.  And it wasn’t every model either, but almost every model has roller lifters

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11 hours ago, ragedracer1977 said:

Why is it that cams and lifters in an automotive engine can sit for years and not do this?

I rebuilt the engine in my Dodge (4.7l V8) with overhead cams.  They were perfect.  Over 250000 miles on it and 17 years old.  Thing sits for months at a time.

Are aircraft manufacturers using a different steel?

I don’t think there is an automobile engine presently produced that has a flat tapped camshaft. Virtually all have gone to roller cams. Reason was the epa decided zinc was harmful to the enviorment. Zink is pretty much a necessity for flat tappet cams. In the early 50”s all the new v8’s were spauling cams. They chased metallurgy using steel cams with cast iron lifters and different metallurgy for the cst iron cams with steel lifters etc. the problem was industry wide. The fix turned out to be formulating oil with zink added.

I've often wondered if Lycomimg had cam problems before the 1980’s. I’m not sure when zink was totally eliminated from auto engine oil but if it is still in aircraft oil I’m sure it is a minimal amount. Something like 100 low lead but now 50 weight low zink oil.  Maybe the new oil is the real culprit? Just an educated guess.

 

 

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Hmmm, maybe we are on to something with the zinc. Take a look. Anyone smarter than me have any idea if this is a possible additive that would work?  Heck, maybe camguard has zinc and that’s the secret.  This next sentence is an edit from the original post.  I read camguard’s website and they call some of their additives a “zinc synthetic,” to basically replace the zinc  that was mandated to be reduced in oil. Look at this link. Zinc reduction may be the issue.  I’m now concerned with lead being removed from fuel. https://aslcamguard.com/articles/camguard-1-800-826-9252-oil-additive-5/

 

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On 7/1/2018 at 9:51 PM, carusoam said:

O360 with plenty of issues... over a decade...

None known to be related to the cam...

Sat unused outside for a couple of years prior to my ownership...

Lived Outside eternally.

Lots of unheated cold starts...

Outside in NJ is a pretty unhappy place for a machine...

Better to be an indoor cat than an outdoor one...

Best regards,

-a-

My cat would disagree:lol:

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I don't believe in conspirancy theories. I think we need to be sure we are not ignoring the basics. One big thing is making sure the oil iin the engine is actually dry. This means we need to be sure that our true oil T is where it needs to be (180° F) to boil off water. Water in the oil compounded with an engine that may not fly as regularly causes corrosion. Then operating that engine with rust accelerates wear. How many of us have tested and are really sure the oil T gauge is telling us the truth? 

Back to the basics that are within our control: use a top quality oil, change it frequently and be certain of it's temp.

Incidentally this explains, in my mind at least, why the efficacy of additives like camguard is very subjective. Water condensed in the oil causes rust no matter what anyone trying to sell their magic potion says. It needs to be boiled out.

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On 7/2/2018 at 5:15 PM, jetdriven said:

There isn’t an expensive certification process for this. The roller cam change  was like 3 engines that flew 300-500hr each. The faa agreed, it’s a minor change and they updated the drawings and castings and started making them.  And it wasn’t every model either, but almost every model has roller lifters

Its really curious how they think  a roller cam would help stated corrosion issues

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1 minute ago, mike_elliott said:

Its really curious how they think  a roller cam would help stated corrosion issues

I don't think it helps reduce corrosion. Water in the oil will cause corrosion. I think they greatly reduce friction and thus damage done by rust. 

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1 minute ago, PTK said:

I don't think it helps reduce corrosion. Water in the oil will cause corrosion. I think they greatly reduce friction and thus damage done by rust. 

I agree, an anti scuff/friction agent and an anti corrosion agent would help. Possibly a redesign of the lubrication system would be in order to really fix the problem. Modern car engines, even in the well documented hell hole of Florida by those that espouse all planes are junk that live there, do not have the issue.

Before moving, I went thru my "junk" and threw out a camshaft I had from one of my old race engines. It had been sitting from 1976 until 2012 uncoated, except from the residual oil left on it when removed. No visible rust

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