O-235 corroded camshaft; advice

[cgzro]

Broken stud makes sense. Torquing up the exhaust nut its easy to break the stud off flush in the head if its corroded, that can mean removal of the cylinder to get it out/replace it. I broke one off once but fortunately was able to get it out with a back-out device and a lot of very careful drilling of a small hole in the center of the broken stud.

My engine was repaired by Aeroatelier in Quebec. Fairly fast turn around (3 weeks I think) no issues that I'm aware of, engine has run fine since then.

Peter

[SeptRepair]

Nothing more infuriating then breaking off an exhaust stud in a cylinder. Can add a whole shit load more work than anticipated, as well having to now break it to the customer a simple exhaust repair has turned into a re and re of the cylinder plus the pissing around of stud removal. To add in this guys case, as a good engineer should do, take a look inside while you have the cylinder off to ensure everything is good. These are one of those prime examples where "joe" mechanic is now the bearer of bad news and the customer is agitated at the added costs he wasnt expecting. The customer is going to want to sit on making a decison for the next while and have his aircraft stored to the side while he figures it out. I have an idea how this will end. Anybody here like to add the ending from the mechanics perspective?

[Hornblower]

Broken stud, … I suppose that's quite possible on an aircraft that has been sitting around for so long. I didn’t think of that ‘cause I haven’t had one break on me (on an aircraft anyways) … but it’s entirely possible; too bad.

The Lycoming overhaul manual says that the bearings (both con rod and mains) have to be replaced at each removal, so Leavens is just following the manual. That’s also too bad because you wouldn’t have to do that on other engines if the bearings were still good. The bearings aren’t that expensive anyways … $200 - $300; try to find some PMA’d ones like ECI stuff.

Now it seems a number of things have not gone right on this job, from possible stud breakage, to cylinder removal without owner’s consent, to bad planning for the compression test and oil screen inspection (maybe). Because now you have to figure out whether or not to replace cylinders … if you don’t replace them before the engine is reassembled and then they are still low after a hot compression test, who’s going to pay to pull them off again? 21/80 is real low, even for a cold test. The guy should have taken it outside and run it, and done the test again before pulling off the exhaust. Better planning on your part as well as the AME’s might have avoided some of this guessing and added expense.

Unless you are a skilled mech, I wouldn’t suggest you take the engine apart yourself. I know it’s pretty simple tech engine, however you need to be really careful on reassembly; the type of care you can only apply after years of experience. And it would also be illegal if you’re not an AME. If you messed it up, it could cost more than you would believe.

To answer Sept Repair … law suit?

[niss]

Had the stud on my Lyc O-320 break this last annual when we had to replace the exhaust.

Not fun.

What do most shops do from a customer service standpoint? I understand that somethings are beyond the AMEs control but finding out that YOU broke the stud and I have to pay to fix aint fun.

I did not mind all that much as it was only another $300 when we were all said and done and my mechanic was actually staying after work etc, just so I could help with the annual. For this reason I did not particularly care about that extra expence. I looked at as a learning experience as now I have an idea as to how to Re & Re a jug, but If my mechanic wasn't so nice as to work with my schedule and it was just joe blows shop, I would not have been impressed in the least bit.

[SeptRepair]

Not much we can do from a customer relations stand point. I dont have counseling sessions for those distraught over an extra couple hours of labour added. The studs that break are usually severely rusted and havent been off since they were installed new. Its interesting you're happy when you were allowed to stay after hours and have the mechanic himself stay and deal with this problem, but would have been pissed if you had to follow their work schedule and pay like the average consumer would in lets say a car shop. To me this is the epitome of the culture in this the industry so many of us mechanics have grown to hate.

[niss]

Its interesting you're happy when you were allowed to stay after hours and have the mechanic himself stay and deal with this problem, but would have been pissed if you had to follow their work schedule and pay like the average consumer would in lets say a car shop. To me this is the epitome of the culture in this the industry so many of us mechanics have grown to hate.

I should have rephrased that. I was certainly annoyed that I was looking at the extra labour to re&re the cylinder + the 180$ to have the engine shop change the stud.

But given the amount my mechanic has done for me to allow me to help out and learn I wasn't about to spit in the plate I eat from.

Now from a customer standpoint, if I was not getting what I deem to be excellent CS from my mechanic by working around my schedule so I could partake in the annual, I would have been very annoyed at being stuck with this bill.

Now shit certainly does happen, and you are right, those studs were probably not off since first install, and they were very prone to break but where would you go from a business standpoint and a customer service standpoint? Say sorry pal, deal with it?

[SeptRepair]

I tend to be heartless when it comes to material possesions and when they break. In not so many words I would tell them to suck it up.

[corroded_camshaft]

I've gotten the engine back from the shop, they replaced the camshaft, lifters, pushrods, piston rings, and one of the gears in the oil pump (as well as a few other odds and ends)

Turned out to be a lot more expensive than the quote I got from them originally, all because of the rings. Im finding out the 235 is an expensive engine heh. Off the top of my head I think there was about 3000 dollars in rings alone! Total for the engine repair was just over 8200 dollars (yikes)

But now the engine is back, its fixed, and they said the compressions during bench test were better than expected, around 77-78.

Turns out the camshaft wasnt so bad, it was new at overhaul and could have been regrounded but I opted for new, only an extra hundred bucks. The lifters were reground at overhaul and again I opted for new rather than reground for an extra 100 bucks there too.

The pushrods were a bright redish orange instead of black. But aside from that they told me the engine was in good condition. One cylinder had a little corrosion inside but that was taken out when they honed the cylinders.

My AME should have the engine back on the plane in two/three weeks and then it'll be the break in. I was given 8 extra quarts of Shell 80 and a jug of Shell 2F preservative oil for when the engine sits idle for more than a month. Now that I have it I'll be extra sure to use it!

[Dust Devil]

I've gotten the engine back from the shop, they replaced the camshaft, lifters, pushrods, piston rings, and one of the gears in the oil pump (as well as a few other odds and ends)

Turned out to be a lot more expensive than the quote I got from them originally, all because of the rings. Im finding out the 235 is an expensive engine heh. Off the top of my head I think there was about 3000 dollars in rings alone! Total for the engine repair was just over 8200 dollars (yikes)

But now the engine is back, its fixed, and they said the compressions during bench test were better than expected, around 77-78.

Turns out the camshaft wasnt so bad, it was new at overhaul and could have been regrounded but I opted for new, only an extra hundred bucks. The lifters were reground at overhaul and again I opted for new rather than reground for an extra 100 bucks there too.

The pushrods were a bright redish orange instead of black. But aside from that they told me the engine was in good condition. One cylinder had a little corrosion inside but that was taken out when they honed the cylinders.

My AME should have the engine back on the plane in two/three weeks and then it'll be the break in. I was given 8 extra quarts of Shell 80 and a jug of Shell 2F preservative oil for when the engine sits idle for more than a month. Now that I have it I'll be extra sure to use it!

Sounds like things ended ok while being a little pricey. I would speak to your AME about communicating better though. If I need to have a jug removed or anything above what was expected I would expect a call should be made. Granted it is what it is and if it was a broken stud there isn't much you can do about that. Good clear communication between the operator and maintenance is absolutely critical to maintaining a good trusting relationship with your AME.

I've never owned a bird outside a commercial operation with a heavy revenue stream to fund maintenance. I can sympathize though with the costs some of this stuff can have for folks with even healthy incomes. This game is pricey that's for sure.

[velcrowagon]

Why would you ever pay $3000 for a ring set?

A bit too late now but in the future look around for PMA'd stuff. I got a full set of rings from ECI for my O-235C2C for about $500 (that's 4 holes).

Hope you're happy with the quality of the work you received because you sure paid for it.