Replacement Normally Aspirated Cylinder Discussion

MBDiagMan

MBDiagMan

Final Approach
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I may be coming up on engine rebuild. Whether I choose an engine shop or field overhaul, I have to make a cylinder choice. I have had good luck with Superior cylinders in the past, but maybe there are advantages that are worth the extra money for nickel, chrome or other cylinders.

I thank you in advance for sharing your knowledge and experience.
 
If you are doing a full engine overhaul then I would go with Superior or the manufacturers cylinders. If you were just doing a top overhaul there are some merits for chrome especially if you don’t fly the plane very often.
 
MBDiagMan said:
I may be coming up on engine rebuild. Whether I choose an engine shop or field overhaul, I have to make a cylinder choice. I have had good luck with Superior cylinders in the past, but maybe there are advantages that are worth the extra money for nickel, chrome or other cylinders.

I thank you in advance for sharing your knowledge and experience.
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What engine?
 
When it comes to angle valve cylinders the options become fewer (and more expensive). Is this a wide deck or narrow deck engine? You may be repairing what you have if it is narrow deck.

If given options I'd buy a set of new Lycoming cylinders.
 
The kit comes with a lot more than just new Lyc cylinders. You get all new Lyc pistons, piston pins, rings, valves, valve springs, gaskets, etc. The last ones I ordered came with the pistons already fitted into the cylinders. The rings were pre gapped, installed and ready to slide on.
If I remember correctly the rockers, rocker shafts and covers are about the the only items not included in the cyl kit.
 
MBDiagMan said:
How do I know if it is wide deck or narrow deck?
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Look at the cylinder mounting nuts. If they're a normal hex type nut then it is a wide cylinder flange engine. If the outside of the nut is smooth and the teeth are on the inside, requiring a tool to be inserted into it, then it is a "standard flange" which is also known as a narrow deck.

I'm guessing you'll have a wide deck engine but it depends on the age of it. The wide deck engines are more supported, Lycoming isn't terribly interested in supporting the older engines anymore.
 
MBDiagMan said:
How do I know if it is wide deck or narrow deck?
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Also check the engine serial number. If it ends with the letter “A” it’s probably a wide deck. There are a few models that didn’t adhere to “A” rule so you’ll still want to check the flange nuts to be sure.
 
MBDiagMan said:
I may be coming up on engine rebuild. Whether I choose an engine shop or field overhaul, I have to make a cylinder choice. I have had good luck with Superior cylinders in the past, but maybe there are advantages that are worth the extra money for nickel, chrome or other cylinders.

I thank you in advance for sharing your knowledge and experience.
Click to expand...

i bought Continental clone cylinders for my Lyc IO360A; cheaper, and they're holding up!
 
What makes you think you might be coming up on overhaul? Has it been given you trouble, or just for precautionary reasons?
 
Seems to me that aftermarket cylinders have had far more ADs than OEMs. It's a result of having to learn some stuff the hard way. The OEMs learned all that a long time ago and don't mess up nearly as often.

OEMs have had ADs result from contracting-out the manufacture of some stuff. Crankshafts, especially, come to mind. The contractor either inadvertently misses something, or deliberately shortcuts the process.
 
Dan Thomas said:
Seems to me that aftermarket cylinders have had far more ADs than OEMs. It's a result of having to learn some stuff the hard way. The OEMs learned all that a long time ago and don't mess up nearly as often.
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I suspect some of the ADs were more political but regardless, there are far fewer ADs on the OEM cylinders than the aftermarkets. Additionally, aftermarket angle valve Lycoming replacement cylinders are a relatively new thing. When I went looking to get any angle valve cylinder for the engine I was working on 10 months ago Continental listed a cylinder kit but they weren’t actually available. None of these things add up to something I’d want to stake $10k or more on.

The good news is that the engine in question is a wide deck. New Lycoming cylinders should be available for that application with minimal headache other than writing the check.
 
Jdm said:
What makes you think you might be coming up on overhaul? Has it been given you trouble, or just for precautionary reasons?
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The engine was making metal at the last annual. I flew it fifteen hours afterwards then cut the filter again and sent an oil sample for analysis. There was metal in the filter. This is an 1,100 hour since overhaul engine. At 1,000 hours the cylinders had been removed for inspection. Cam and everything inside looked good. Cylinders were honed and new rings fitted. Number three cylinder ran hot. It probably reached 450 a few times and ran a lot over 400.

When metal was discovered at annual, a cylinder was removed for internal inspection and again cam and everything looked good. During the fifteen hours oil pressure would stabilize at 80 or 81 and oil temp would be consistently be between 179 and 181.

I am anxiously awaiting oil analysis which was mailed almost three weeks ago. Analyzing possibilities for overhaul if the analysis calls for it. If I am really lucky a cylinder is making the metal. If unlucky it will have to be split or an overhauled engine purchased.
 
Wow. That is a tough one. Sounds like it’s being tackled with good direction. Hopefully it turns out satisfactory.
I tend to go for the better options when I plan to hang on to an airplane for a long time. If it comes down to a rebuild I would almost always lean toward an engine shop rather than a field overhaul. I’d definitely go with new lycoming cylinder kits if I intend to keep the airplane for years to come.
 
I had BPE in Tulsa build the engine for my RV-10. They were ambivalent between Lycoming and Superior and chose based on price and/or availability.
 
The oil sample was sent to Blackstone almost a month ago. It was sent regular mail, no Trk number and has not yet arrived. The Post Office needs to just be closed, the management fired and start all over again. I have had serious problems with the post office in the last year that have cost me a lot of money and caused a lot of problems.

I am stuck until I get the oil analysis.:mad:
 
MBDiagMan said:
The oil sample was sent to Blackstone almost a month ago. It was sent regular mail, no Trk number and has not yet arrived. The Post Office needs to just be closed, the management fired and start all over again. I have had serious problems with the post office in the last year that have cost me a lot of money and caused a lot of problems.

I am stuck until I get the oil analysis.:mad:
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I hear you. One sample I sent to the lab I use (AoA) recently took 5 days to go from Tucson, to Phoenix, a distance of around 120 miles and then _another_ 4 days to go to the destination post office in Phoenix ... and they don't even do mail sorting here in Tucson anymore other than priority, any first class and lower mail goes to Phoenix first anyway! I've always been a big fan of the USPS, but things have gotten pretty bad of late.
 
I be very surprised if anything conclusive comes from the results anyway. They always seem to be vague and inconclusive.
 
Do I understand the story?
Engine making metal, oil analysis pending?

I have wanted to ask others in the know before; 'how many engines that make metal then go on to heal or self-fix?' I suspect, but have no evidence, that almost all of those making significant metal (not a spec/flake/granule or two, but each pleat with obvious shower of metal) go on to need a teardown pretty soon after.
 
I’ve been told that for Lycoming the factory cylinders are the best and last the longest.
 
Let'sgoflying! said:
Do I understand the story?
Engine making metal, oil analysis pending?

I have wanted to ask others in the know before; 'how many engines that make metal then go on to heal or self-fix?' I suspect, but have no evidence, that almost all of those making significant metal (not a spec/flake/granule or two, but each pleat with obvious shower of metal) go on to need a teardown pretty soon after.
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Actually, making metal once and then not again does happen, but that’s not why I’m waiting for test results. Oil Analysis can indeed help identify where the metal is coming from. What if I tore down, rebuilt the engine entirely only to learn afterward that the metal is coming from the prop Governor? What if it is coming from a cylinder, and I split and rebuilt the entire engine?

I understand that after making metal in the filter twice that something needs attention, but with really good oil pressure and temp as well as a recent cylinder removal revealing very nice internals, I want as much info as possible before laying out 30 grand.

I am holding out hope that a cylinder or the prop Governor are responsible. A friend has a Mooney just like mine. At the same time mine showed metal so did his and it turned out to be a cylinder. I had a cylinder that was running hot, so it is possible.

It is a given that it will need attention. I want as much information as possible to aid in determine exactly what attention it needs.
 
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I don’t believe Oil Analysis can identify the alloy which is necessary to find the source.

There are places that can check Filter Chips and identify the alloy.

Aviation Laboratories ( Av Labs) is one agency.

Costs a little more than Oil Sample though.
 
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Here’s an example. I recently had a customer with an intermittent engine problem that had been given him trouble for a long time. One of the main problems found was an intermittently sticking intake valve. Yes, intake! The engine had to run an hour or so at cruise before the malfunction would intermittently duplicate. Compressions checked good on 3 occasions. The problem was ultimately found by a simple visual inspection of the rocker. The intake rocker was hammered in by the sticking valve which caused a significant amount of metal to be worn away. See pic. This engine had regular oil analysis since it’s overhaul 500 hours (10yrs) ago. The analysis revealed nothing useful to help identify our problem.
Not saying they can’t be helpful. It’s good information to have alright. I’ve just never been fortunate enough to get anything conclusive from them.
 

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Great example Jdm! Let’s say that my engine has the same problem. I would be pleased if it is. In that case, buying an exchange engine from one of the engine shops would put me back in business, but would it have been the most expeditious approach?

I agree that an oil analysis is not conclusive. In the case the only thing that is completely conclusive is exploratory surgery.

In my case, with a competent postal system, I would already have the analysis. Maybe it would have been helpful and maybe not, but I could be moving along with it. My engine guy has decades and decades of intensive aircraft piston engine service experience. and he wants the results before the next step. If we had known that it would take more than a month to get it, and maybe never get it, we would have done something different.
 
I just had my analysis come back, but all they provided was the ppm and not the acceptable ranges for an IO-360 (Steel cylinders). Last analysis showed that my numbers were all good except silicon was elevated and they blamed that on likely bad scat tubing or air filter allowing dirt into the engine. I would compare these numbers to my previous analysis, but I can't find it and my mech in Oregon is currently without power due to the snow storm.
Any help in understanding these numbers would be helpful!

Iron: 43.3
Copper: 4.0
Nickel: 1.4
Chromium: 11.8
Silver: .1
Magnesium: .8
Aluminium: 8.4
Lead: 3116
Silicon: 8.6
Titanium: <.1
Tin: <.1
Moly.: .6
 
guzziguy said:
I just had my analysis come back, but all they provided was the ppm and not the acceptable ranges for an IO-360 (Steel cylinders). Last analysis showed that my numbers were all good except silicon was elevated and they blamed that on likely bad scat tubing or air filter allowing dirt into the engine. I would compare these numbers to my previous analysis, but I can't find it and my mech in Oregon is currently without power due to the snow storm.
Any help in understanding these numbers would be helpful!

Iron: 43.3
Copper: 4.0
Nickel: 1.4
Chromium: 11.8
Silver: .1
Magnesium: .8
Aluminium: 8.4
Lead: 3116
Silicon: 8.6
Titanium: <.1
Tin: <.1
Moly.: .6
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Those numbers look pretty normal to me. Most companies will not provide “acceptable ranges” . They primarily are tracking the data and will alert you to an anomaly. I’m sure they have done enough that they could say whether one was worryingly high but that is assuming responsibility for your engine health.
 
MBDiagMan said:
Let’s say that my engine has the same problem. I would be pleased if it is. In that case, buying an exchange engine from one of the engine shops would put me back in business,
Click to expand...

If you had the same issue all you would need is some basic cylinder work on the problem one. Wouldn’t need another engine for this situation alone. Very easy to check by pulling all the rocker covers. Even pulling the rockers themselves doesn’t take that long, and can be done while the cylinder is on the airplane. I’ve been at this A&P stuff myself for almost 35yrs and have never had this exact problem before.
 
MBDiagMan said:
The oil sample was sent to Blackstone almost a month ago. It was sent regular mail, no Trk number and has not yet arrived. The Post Office needs to just be closed, the management fired and start all over again. I have had serious problems with the post office in the last year that have cost me a lot of money and caused a lot of problems.

I am stuck until I get the oil analysis.:mad:
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Well I use USPS for most of the things I ship and most of the things I receive. Almost always use priority mail and insure if needed. Getting things to Juneau with UPS and Fed Ex is expensive. Priority mail works great for me and is just as quick as UPS or Fed Ex.
 
MBDiagMan said:
Actually, making metal once and then not again does happen, but that’s not why I’m waiting for test results. Oil Analysis can indeed help identify where the metal is coming from. What if I tore down, rebuilt the engine entirely only to learn afterward that the metal is coming from the prop Governor? What if it is coming from a cylinder, and I split and rebuilt the entire engine?

I understand that after making metal in the filter twice that something needs attention, but with really good oil pressure and temp as well as a recent cylinder removal revealing very nice internals, I want as much info as possible before laying out 30 grand.

I am holding out hope that a cylinder or the prop Governor are responsible. A friend has a Mooney just like mine. At the same time mine showed metal so did his and it turned out to be a cylinder. I had a cylinder that was running hot, so it is possible.

It is a given that it will need attention. I want as much information as possible to aid in determine exactly what attention it needs.
Click to expand...

A good engine shop should be able to diagnose this without oil analysis if the problem is as bad as described. You also need to consider that the metal will migrate and even if the problem is a cylinder or prop governor the metal may end up embedded in the bearings. It is also possible that the metal you're finding now is remnant from the first problem and it is continuing to find its way through the oil system.

Personally, I'd quit waiting for the oil sample and start investigating.
 
Grum.Man said:
Those numbers look pretty normal to me. Most companies will not provide “acceptable ranges”.
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Each Blackstone report provides your past 5 analyses, so each report shows your last 6 analyses. "Unit/Location Averages" and "Universal Averages" are less useful. The problem with "Unit/Location Averages" (your plane) is if you have had an overhaul the averages span before and after analyses. Universal Averages are across all aircraft types.
 
If the sample was not taken properly it will be in error.
 
The sample was taken properly but what difference does it make if the post office is so incompetent that they can’t deliver it to them?

The shop has been busy and was awaiting the oil sample before investigating. It is shut down this week due to weather. We expected oil sample to be part of the equation before tear down. I expect that we will start exploratory surgery as soon as things open back up around here. The shop has a facility across the taxiway from my hangar as well as at an airport 60 miles away and they juggle work between the two locations.
 
Jdm said:
If you had the same issue all you would need is some basic cylinder work on the problem one. Wouldn’t need another engine for this situation alone. Very easy to check by pulling all the rocker covers. Even pulling the rockers themselves doesn’t take that long, and can be done while the cylinder is on the airplane. I’ve been at this A&P stuff myself for almost 35yrs and have never had this exact problem before.
Click to expand...

Although I’m not an A&P, I grew up in my dads car shop and have lots of engine experience from the days when valve jobs and in frame overhauls were commonplace.
 
MBDiagMan said:
The oil sample was sent to Blackstone almost a month ago. It was sent regular mail, no Trk number and has not yet arrived. The Post Office needs to just be closed, the management fired and start all over again. I have had serious problems with the post office in the last year that have cost me a lot of money and caused a lot of problems.

I am stuck until I get the oil analysis.:mad:
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It took 6 weeks for a regular, first class envelope (think greeting card or bill payment) to get from DC suburbs to Detroit in December/January.

This is the same postal service that not only took 4 weeks to get a "priority" package with several rolls of film from DC suburbs to Nashville - and they x-rayed the package destroying all the photos on the rolls.

Never again.
 
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