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Posted
11 minutes ago, FloridaMan said:

My mechanic has saved at least two rockets from an overhaul by catching this early. 

Who is your mechanic, and where will he get the new lifters?

I'm wading through the annual from hell and, while there are other things being attended to now, lifter and cam inspection is on the list.

Posted

This is pretty widespread. We pretty much plan to inspect all the lifters on continentals as part of the prebuy inspection.  Alternator too. It’s expensive but a lot cheaper than a whole engine. 

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Posted
5 minutes ago, jetdriven said:

This is pretty widespread. We pretty much plan to inspect all the lifters on continentals as part of the prebuy inspection.  Alternator too. It’s expensive but a lot cheaper than a whole engine. 

Do you have a source for the new whiz-bang hardened lifters, or do you just use the original ones.  I have seen some advertised ("regular ones"), but my Internet search hasn't turned up anything on the "new" lifters.  Maybe I dreamed it.

Posted
47 minutes ago, jetdriven said:

This is pretty widespread. We pretty much plan to inspect all the lifters on continentals as part of the prebuy inspection.  Alternator too. It’s expensive but a lot cheaper than a whole engine. 

Can you get DLC lifters for Continental engines?

Posted
Several minutes with my favorite search engine suggests that you can't.

You can not, but you also can not change out a lifter in a Lycoming without splitting the case! Lifters can be easily inspected and changed in a Continental. Since they typically see more cylinder work they also get more attention to lifters.


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Posted
On 10/22/2023 at 8:10 PM, jetdriven said:

This is pretty widespread. We pretty much plan to inspect all the lifters on continentals as part of the prebuy inspection.  Alternator too. It’s expensive but a lot cheaper than a whole engine. 

And THANK YOU for that.  Your advise got me a new set of lifters from the seller.

Posted

We checked the lifters during Myrtle’s last annual, at about 800hrs on the engine. We replaced one due to wear. The rest looked good. 

Posted
On 10/22/2023 at 7:10 PM, jetdriven said:

This is pretty widespread. We pretty much plan to inspect all the lifters on continentals as part of the prebuy inspection.  Alternator too. It’s expensive but a lot cheaper than a whole engine. 

Are you suggesting that this is a TSIO-520-NB issue?....Or all Continentals?

There are literally an order of magnitude more Continental - 6's in the Beech fleet than in Mooney (2 orders of magnitude more 520's than the small Rocket 305 fleet). In either case, if this is widespread, then it should be all over BeechTalk . 

Also is this something that just popped up since Oshkosh?  At that time Mike Bush said the following regarding Continental cams and lifters.  It is just one man's opinion but Savvy would be seeing it and he would be well aware:

“Hi, Tom. I just arrived in Oshkosh, saw your email, and read through the Beechtalk thread. My reaction is that it's utter nonsense.

First, we've seen absolutely no evidence of premature camshaft wear in low-time engines. We have seen a lot of perfectly good engines removed from service prematurely by overzealous A&Ps who condemn a camshaft because it exhibits minor pitting or normal wear. Continental has an excellent service bulletin SID05-1B that provides guidelines for cam and lifter inspections. While its guidance on lifters makes no sense (it claims that up to 10% spalling is acceptable and that lifters are "self-healing"), its guidance on camshafts is pretty good and we've used it to save many of our clients' engines from needless euthanasia. AID05-1B makes it clear that considerable cam lobe wear is acceptable, that corrosion or pitting on any portion of the lobe other than the apex (toe) of the lobe is of no concern, and that the only thing that should cause a cam lobe to be considered possibly unairworthy are "crack-like features" or "indentions" on the apex of the lobe with sufficient depth to repeatedly catch the tip of a sharp pick or awl. I preferred the prior version SID05-1A that only talked about "crack-like features" and was sorry to see SID05-1B add "indentions" (which my dictionary research says is an archaic form of the word "indentations" LOL). Personally, I would only consider a lobe unairworthy is crack-like features were found on the lobe apex and were of sufficient depth to flunk the fingernail test...but that's me.

....So there you have my $.02 on this Beechtalk thread. I don't really find anything credible there.”

https://www.beechtalk.com/forums/viewtopic.php?f=37&t=221178

Is the cam lifter crisis over???

Arnie Itzkowitz
 Post subject: Is the cam lifter crisis over???
PostPosted: 24 Jul 2023, 07:36 
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I started the cam lifter thread after discussion with my A&P: I spoke to Tom Haines who spoke with Mike Busch. Below is the reply:

Good morning, Arnie. Nice chatting yesterday. I did reach out to Mike Bush and got this lengthy reply. So, while it’s one man’s opinion, it is from someone who has literally written the book(s) on aircraft engines and how to operate them. I hope it is helpful. Mike says it is fine if you want to use some or all of it on BT.

“Hi, Tom. I just arrived in Oshkosh, saw your email, and read through the Beechtalk thread. My reaction is that it's utter nonsense.

First, we've seen absolutely no evidence of premature camshaft wear in low-time engines. We have seen a lot of perfectly good engines removed from service prematurely by overzealous A&Ps who condemn a camshaft because it exhibits minor pitting or normal wear. Continental has an excellent service bulletin SID05-1B that provides guidelines for cam and lifter inspections. While its guidance on lifters makes no sense (it claims that up to 10% spalling is acceptable and that lifters are "self-healing"), its guidance on camshafts is pretty good and we've used it to save many of our clients' engines from needless euthanasia. AID05-1B makes it clear that considerable cam lobe wear is acceptable, that corrosion or pitting on any portion of the lobe other than the apex (toe) of the lobe is of no concern, and that the only thing that should cause a cam lobe to be considered possibly unairworthy are "crack-like features" or "indentions" on the apex of the lobe with sufficient depth to repeatedly catch the tip of a sharp pick or awl. I preferred the prior version SID05-1A that only talked about "crack-like features" and was sorry to see SID05-1B add "indentions" (which my dictionary research says is an archaic form of the word "indentations" LOL). Personally, I would only consider a lobe unairworthy is crack-like features were found on the lobe apex and were of sufficient depth to flunk the fingernail test...but that's me.

It's important to understand that even a camshaft in severe distress is not a safety-of-flight issue and won't make you fall out of the sky. The camshaft is case-hardened (carburized) to create a very hard outer layer that's roughly 0.015" thick. The cam lobe is only in jeopardy if the apex wears completely through this hardened layer and exposes the softer/tougher inner "meat" of the lobe. Once this case-hardened shell is worn through, wear accelerates and the cam starts making ferrous metal in the filter. But even then, the effect on engine performance is so subtle that pilots typically never notice it. I've seen cams on small Lycomings worn down so badly that you could hardly tell where the apex was, yet none of the pilots noticed any performance degradation (although I'm sure there would have been some if the engine was tested on a dyno).

Second item of nonsense is the discussion of zinc (ZDDP) being removed from Aeroshell and Phillips oils. Fact is there has NEVER been zinc compounds used in any piston aircraft oil, although they are liberally used in automotive oils. Ben Visser wrote a good article on this in which he explained that ZDDP is incompatible with the valve guides used in piston aircraft engines, and that zinc additives should never be used in any certified piston aircraft engine -- the one exception being the Rotax 900-series engines that are designed to be operated on automotive-style oils.

So there you have my $.02 on this Beechtalk thread. I don't really find anything credible there.”

_________________
Regards,
Arnie

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