Cam Shaft Pictures

[slowflyin]

Seeking opinions from the brain trust.   These are pics of an O-540 pre-buy.  

[slowflyin]

Thanks for the feedback.  1500 hours- it's been flying very infrequently the last couple of years but is hangared in a very dry climate.  Thanks again.  

[A64Pilot]

From what I can see it’s a problem, a big problem, a split the case to fix problem, and I’m the guy that if I split the cases, I’m overhauling

‘But as I’m looking at it on an Ipad I’ve been fooled by pictures before

[Utah20Gflyer]

It’s kind of hard to predict the future when it comes to what looks like minor cam distress.  What the lifter faces look like would tell us a lot more of the total story.  This cam could run for quite some time or it could go bad in a couple hundred hours.   At 1500 hours if I ended up buying it I would continue running the engine while making sure to pay very close attention to ferrous metal in the filter which is the sign the wear is accelerating.   If the lifter faces are in good shape It wouldn’t surprise me if the engine made it to 2000 hours.  If the lifter faces are all chewed up the CAM could be toast in 100 hours.   So we don’t don’t really have enough information to say anything definitive other than this is a higher risk motor than one with a pristine CAM.  

[slowflyin]

Thanks for all the comments!

[PT20J]

If I liked the airplane, I'd negotiate the best price I could and I'd run the cam until it starts making metal in the filter. It might go awhile and worn cams don't cause engines to suddenly fail; they just cause a slow reduction in power as the lobes wear down decreasing valve lift. But' I'd figure an overhaul is in the future somewhere in the next few hundred hours and plan and budget accordingly.

[philiplane]

the condition of the faces of the lifters are more important than the cam lobe. A perfect cam lobe will be ruined quickly if it's running against a severely pitted lifter, but a good lifter running against a few pits on the cam generally will not be any problem.

[MBDiagMan]

….and….. a bad lifter started getting bad from pitting that was caused by corrosion.  The pitting results in metal circulating in the oil that is also bad for the overall engine health.  When rebuilding these engines, insist on DLC lifters or convert to roller lifters.  If you do, you won’t have to deal with this problem a second time.

Edited June 8, 2023 by MBDiagMan

[Pinecone]

Nice thing about Continentals is you can change out the lifters without splitting the case.

[MBDiagMan]

Yes, if I were to put back in service an aircraft that had been setting up a long time and it had barrel lifters, I would replace all of them and then go on about my business.  This is not easily done with mushrooms.  Not only are most continentals barrel lifters, but the cam is low where it holds oil better to prevent corrosion.

[N201MKTurbo]

Looks like a normal high time engine to me. I wouldn’t lose any sleep over it. If I was buying the plane, I wouldn’t add or subtract anything for the pictures. 

[slowflyin]

Thanks for all the comments!  Yes, high time engine.  I priced it as run out but I'm optimistic.  Any additional time is free time.  I'll be running oil analysis and cutting filters.   Hoses, motor mounts, exhaust system....have been recently replaced.   The engines on an 81 Skylane II.  She's rated 235 HP @ 2400.  Feels like she's loafing along in cruise.   Thanks again!

[A64Pilot]

The 235 is one of the longest lived engines there are, because in my opinion  even wide open it’s loafing, it’s seriously De-rated. They will go WAY beyond TBO.

I overhauled my IO-540-W1A5D at 2,000 hours and on tear down everything except the Cylinders met NEW specs, not serviceable, but new specs so there was no measurable wear. Cylinders may have but I had bought 6 new Milleniums prior to tear down, stupid I know now.

The I/O 235 especially as it’s a high compression engine it’s redline is 2400 RPM, I believe it’s identical to the 260 HP except for RPM.

The O version is a low compression engine and as such has to turn higher RPM to make 230 HP. It’s semantics of course but I believe in a Cessna it’s a 230 hp engine and not a 235 because the aircraft was originally Certified with the 230 HP O-470.

However as it’s a low compression engine in other aircraft at least there are Mogas STC’s, surely there is for the 182 also. If so, you won’t care much if 100 LL goes away and it’s replacement is $10 a gallon.

You are saying it’s a carbureted O and not a fuel injected I/O?

If you choose to run it until it starts making metal I’d advise you to purchase an Overhaul exchange through Lycoming, reason is if it’s making metal there is a very good chance that the crank and other hard parts are bad and they can easily drive the Overhaul costs to equal or exceed Lycomings price but factory engines usually bring more at sale than field overhauls.

Just noticed your last post where you said it’s 235 at 2400, that’s a high compression I/O, not an O and as such you can’t run Mogas

[slowflyin]

On 6/9/2023 at 10:56 AM, A64Pilot said:

The 235 is one of the longest lived engines there are, because in my opinion  even wide open it’s loafing, it’s seriously De-rated. They will go WAY beyond TBO.

I overhauled my IO-540-W1A5D at 2,000 hours and on tear down everything except the Cylinders met NEW specs, not serviceable, but new specs so there was no measurable wear. Cylinders may have but I had bought 6 new Milleniums prior to tear down, stupid I know now.

The I/O 235 especially as it’s a high compression engine it’s redline is 2400 RPM, I believe it’s identical to the 260 HP except for RPM.

The O version is a low compression engine and as such has to turn higher RPM to make 230 HP. It’s semantics of course but I believe in a Cessna it’s a 230 hp engine and not a 235 because the aircraft was originally Certified with the 230 HP O-470.

However as it’s a low compression engine in other aircraft at least there are Mogas STC’s, surely there is for the 182 also. If so, you won’t care much if 100 LL goes away and it’s replacement is $10 a gallon.

You are saying it’s a carbureted O and not a fuel injected I/O?

If you choose to run it until it starts making metal I’d advise you to purchase an Overhaul exchange through Lycoming, reason is if it’s making metal there is a very good chance that the crank and other hard parts are bad and they can easily drive the Overhaul costs to equal or exceed Lycomings price but factory engines usually bring more at sale than field overhauls.

Just noticed your last post where you said it’s 235 at 2400, that’s a high compression I/O, not an O and as such you can’t run Mogas

It’s an O-540-L3C5D.  Carbureted and rated at 235 HP.    I’m hoping regular oil analysis  will offer me some foreshadowing before things get out of hand.   I concur, no MOGAS STC for this variant.  Thanks for your comments.