Overhaul - New Cylinder wait times

[Jchappe7]

Anyone have any ideas on how long the wait is on the 0-360-A1D new cylinder kits are taking?  I can't seem to get straight answer from Superior or Lycoming.  Any help is appreciated?  I am looking for 4 of the SL36006W-A20P (millennium) or the Lycoming.  Thanks

[jetdriven]

Lycoming. Never.  Superior is backed up 3-6Mo from air power. 

[Utah20Gflyer]

Isn’t continental also making cylinders for Lycoming engines now?  Maybe that’s another option. 

[Jchappe7]

I haven't heard that one yet?  I will check.  Is there any reason I can't use my current cylinders if they are in good shape after an overhaul?  I only have 550 hrs on my current cylinders....

 

[hammdo]

IRAN or overhaul - are they first run cylinders? If so, that may be the way to go…

-Don

[Jchappe7]

I am going to do a major Overhaul.  The cylinders I have were re-worked when they went on 550 hrs ago.  I think this is what you were asking @hammdo

[Ragsf15e]

18 minutes ago, Jchappe7 said:

I am going to do a major Overhaul.  The cylinders I have were re-worked when they went on 550 hrs ago.  I think this is what you were asking @hammdo

If they were already overhauled at least once, you may want new ones (if available).  Most people will consider overhauling 1st run cylinders, but those with multiple overhauls or unknown history may have many thousands more hours and could be more prone to failure.  They might also be fine.  It’s tough to say for certain which is why @hammdo asked.

I thought when I looked at TCM cylinders, they only made angle valve cylinders for io-360, not parallel valve for the o-360 but i could be wrong.

[Jim Peace]

7 hours ago, Utah20Gflyer said:

Isn’t continental also making cylinders for Lycoming engines now?  Maybe that’s another option. 

I have one on my plane. O-360. 
it’s in my #3 position. It does run a bit warmer but it only has about 100 hours on it vs the 1100 hours for the rest. 
 

I sent out the original one to Gipson for overhaul and it’s sitting in a box in my house. I wonder if I replace # 4 with the overhauled if it would make #3 work less and bring the cht down? Or replace #1,  thoughts? 
 

reason I did not do a whole top is that it was covid and I could not get 4 steel matching cylinders. 

[MB65E]

If yours truly only have 550h on them keep them. With an exchanges cylinder you’ll never know how many hours are on the cylinders. You could get a freshly overhauled CYL with 4000h on it. Then it cracks at the exhaust seat 50hr in.

A neat trick is find an engine shop that imports from Japan. They have a mandatory life limit on their engines of 800hr. I found 4 angle valve cylinders for my airplane and had them overhauled. 

But with yours at only 550h keep them!

-Matt

[M20F]

12 hours ago, Jchappe7 said:

I am going to do a major Overhaul.  The cylinders I have were re-worked when they went on 550 hrs ago.  I think this is what you were asking @hammdo

You are spending a lot of dollars that won’t return in resale and won’t make you safer.  I did my engine the first time at 2400 something hours.  It was not a major because I reused a cylinder that had 4hrs on it and another that had about 60.  Due to a case crack I finally did a major somewhere around 3000 hours, even though from a practical standpoint I did one at 2400. 
 
TBO, major, etc are largely misunderstood in aviation.  Mike Busch didn’t go thousands past TBO with no expense.  He just didn’t check all the boxes to get the word “major” in his book.  

[A64Pilot]

Major, light overhaul etc are marketing terms, they don’t exist in the FAA world, you either overhaul or repair.

The FAA does recognize those terms exist and even issued an AC explaining them.

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_43-11.pdf

But technically an overhaul doesn’t require replacement of anything, you could disassemble, clean and inspect and find everything within overhaul limits, re-assemble and test and sign it off as overhauled. Lycoming for example does have an SB that has a list of items that must be replaced, but it’s an SB and therefore you aren’t required to follow it and most in truth don’t fully comply, not everyone replaces every hose for example

https://www.lycoming.com/sites/default/files/attachments/Mandatory%20Parts%20Replacement%20at%20Overhaul%20and%20During%20Repair%20or%20Maintenance.pdf

So the 500 hour cylinders should (may) be within overhaul limits along with the pistons, if so then they could be reused as is in an overhauled engine

When I overhauled my IO-540 everything was within overhaul limits, but I replaced the jugs anyway, in hindsight I probably shouldn’t have. It was a 235 HP 540 and even at T/O power a 540 at 235 HP isn’t running hard at all so they tend to last a really long time

Also there are a lot of commonly used terms like Remanufactured for example that just don’t exist to the FAA.

‘But a “top overhaul” isn’t an overhaul it’s a repair, but as everyone knows what top overhaul means marketing wise it a commonly used term, but I think as a mechanic I shouldn’t sign off in the logbook that I performed a top overhaul, but instead I replaced cylinders 1-4, pistons etc with whatever components were used, overhauled, repaired or new.

Components are of course very frequently overhauled or repaired. To be overhauled the component has to meet the fits and limits as specified in that components overhaul manual.

Bottom line, there can be a HUGE difference in a quality overhaul and one that isn’t but legally they both were an overhaul.

Edited July 16, 2023 by A64Pilot

[cliffy]

As a side note to the above-

The FAA looks upon the sign off of a "Major Overhaul" to include compliance with this clip from Section 4a of the above mentioned AC-

"that are acceptable to the Administrator. In most cases, the standards that are outlined in the Engine Manufacturer Overhaul Manuals are standards acceptable to tho Administrator."

In most if not all such manuals the after overhaul testing is specified to be done with "CALIBRATED" instruments not 50 year old aircraft instruments

If the test run is done in the airplane and those gages haven't been recertified as accurate then the engine "technically" is not "overhauled" it is just "repaired"

Not many follow this requirement but it is still there anyway. (Verified by discussions with the FAA years ago)

[M20F]

8 hours ago, A64Pilot said:

But technically an overhaul doesn’t require replacement of anything, you could disassemble, clean and inspect and find everything within overhaul limits, re-assemble and test and sign it off as overhauled.

I will let others dig out the rules but I don’t believe that is correct. @cliffy gave part of it but on a Lycoming to best of my knowledge as example the exhaust valves have to go to be a major, thus why my first “major” was just IRAN.  I agree from a practical standpoint it makes no sense but this is how I understand the rules to be. 

[A64Pilot]

On 7/16/2023 at 10:24 PM, M20F said:

I will let others dig out the rules but I don’t believe that is correct. @cliffy gave part of it but on a Lycoming to best of my knowledge as example the exhaust valves have to go to be a major, thus why my first “major” was just IRAN.  I agree from a practical standpoint it makes no sense but this is how I understand the rules to be. 

That’s Lycoming’s SB, and it would be foolish to not comply with their SB. There is actually a long and comprehensive list, I linked to it above.

Here it is again https://www.lycoming.com/sites/default/files/attachments/Mandatory%20Parts%20Replacement%20at%20Overhaul%20and%20During%20Repair%20or%20Maintenance.pdf

But it’s not required.

If they incorporated that SB in the overhaul manual and they may have. It’s been quite a while since I have overhauled a Lycoming, but if the overhaul manual says it’s required, then you do have to do it, but SB’s even though many say mandatory, aren’t.

I don’t know why the SB hasn’t been incorporated into the overhaul manual, if it hasn’t been.

Most IA’s won’t sign off an overhaul if the SB wasn’t complied with for liability reasons, show that “Mandatory” SB to a jury and see how it plays.

But the FAA doesn’t require it.

On edit, take a look at that SB, suppose someone just replaced all the jugs and prop strikes when they get home and decides since insurance is paying for the prop strike that they are throwing in the rest and overhauling the engine. Would you tear the jugs apart and replace the valve guides and exhaust guides? Extreme example but absolutes don’t always fit the case.

In this case all he should do is replace guides and exhaust valves, if his bores are within overhaul limits, then they are good to go, and I feel sure exh valves and guides can be had, mind you he doesn’t have to do that if everything is within limits IAW the overhaul manual, but it would be prudent to follow the SB

Edited July 19, 2023 by A64Pilot

[cliffy]

Its interesting to also note that many cylinder overhaul facilities use a conglomeration of parts when assembling cylinders.

You get exchange cylinders with no idea of time on them AND same with the valves.

Not too many shops replace the valves as a procedure on every cylinder. 

I kind of feel that its more a consideration the higher you go in engine HP and total engine work load (turbo, high compression, etc).

where it might be more prudent to replace all the valves as per the SB

Especially sodium filled valves. 

The SB might also be biased toward and overhaul condition with the engine at TBO or more rather than a prop strike at 800 hrs. 

 

[N201MKTurbo]

16 minutes ago, cliffy said:

Its interesting to also note that many cylinder overhaul facilities use a conglomeration of parts when assembling cylinders.

You get exchange cylinders with no idea of time on them AND same with the valves.

Not too many shops replace the valves as a procedure on every cylinder. 

I kind of feel that its more a consideration the higher you go in engine HP and total engine work load (turbo, high compression, etc).

where it might be more prudent to replace all the valves as per the SB

Especially sodium filled valves. 

The SB might also be biased toward and overhaul condition with the engine at TBO or more rather than a prop strike at 800 hrs. 

 

If you send your cylinders to a cylinder shop and say you want them overhauled, I’m sure they would accommodate you. If you just ask for overhauled cylinders, there is no telling what you will get.

[A64Pilot]

You know of course if you buy a “Zero timed” rebuilt engine that comes with a new logbook, that’s what you get, parts from all over the place.

Of course all parts meet specs so it shouldn’t matter. Parts are parts, right?

In fact there are many for example that argue that some used parts, cases for instance are better than new.

But I concur, possibly illogically I prefer taking my cylinders for overhaul, and if possible getting the same one back, not all cylinders can be overhauled of course 

[JimB]

On 7/16/2023 at 1:50 PM, A64Pilot said:

Also there are a lot of commonly used terms like Remanufactured for example that just don’t exist to the FAA.

Yes. The proper term would be "Rebuilt". All the manufacturers like to come up with their own interesting terms...

91.421(c)

For the purposes of this section, a rebuilt engine is a used engine that has been completely disassembled, inspected, repaired as necessary, reassembled, tested, and approved in the same manner and to the same tolerances and limits as a new engine with either new or used parts. However, all parts used in it must conform to the production drawing tolerances and limits for new parts or be of approved oversized or undersized dimensions for a new engine.

[Jchappe7]

Thanks everyone for the great advice!