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Engine Overhaul Recommendations?


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12 hours ago, Steve W said:

All I can say is make sure however your engine gets to the shop that it's insured in transit, even if it's your own car. One of the last things you want to happen is for your newly overhauled engine to get in a car accident... don't ask how I know.

 

Urgh.  That sounds worse than when my new prop met a forklift.  It all ended up getting covered, but I ended up grounded for 3 extra months.

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K...conti 6...got it. Whoever does the OH, I'd check out jewel from what I've read, very reasonable, good reviews, I'd send the cylinders to lycon for a port, polish and flow match. Reportedly, they claim an extra 5hp per cylinder. The cyl have to be redone anyway and they charge an extra 300 for the service. Cheap horsepower. Always liked the idea of putting that 6 in an f or j. Didnt realize anyone had done it. How'd it work out?

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1 hour ago, Pete M said:

K...conti 6...got it. Whoever does the OH, I'd check out jewel from what I've read, very reasonable, good reviews, I'd send the cylinders to lycon for a port, polish and flow match. Reportedly, they claim an extra 5hp per cylinder. The cyl have to be redone anyway and they charge an extra 300 for the service. Cheap horsepower. Always liked the idea of putting that 6 in an f or j. Didnt realize anyone had done it. How'd it work out?

It’s my first plane and it already had the conversion so I don’t really know the difference. The guy who did it flew the plane from the US to Australia and back so I guess it worked out.  I have about 500 hours in it. TAS about 155 at 8.5k. It has good enough power until about 10k, it seems happiest at 11.5/12.5.  Gonna be interesting to see what the difference is when it gets back from OH. 

Edited by SantosDumont
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4 hours ago, SantosDumont said:

Called Jewell and they said around $17k parts and labor, not including mags since I just IRAN'ed them... seems cheap when the shop down the street wants $34k and a factory reman is $42k.  I think I'ma CB this one and get my prop overhauled too.

Jewell is a fine choice, and whom Mike B used on one of his engines. But since you mentioned leaving out Mags,  be aware that Major Overhaul is legally defined term by the FAA that to count as a Major Overhaul, and thus reset  TSMO to 0 in your logs, that we are required to overhaul or replace everything that the manufacturer requires per their documentation. Thus you are likely required to overhaul if not replace the mags. An IRAN of mags doesn't count since its not an overhaul that follows its own parts replacement list. If that's important to you, since its affects resale value, be sure to discuss with whomever does your work exactly what kind of return to service paperwork you'll be getting: IRAN vs Major Overhaul on your engine. An IRAN won't reset the clock on TSMO. 

Here is an excerpt from TCM M-0 Appendix C-2 that covers mandatory replacement parts:

At engine overhaul the starter, starter adapter, alternator, magnetos, and engine fuel system
must be replaced with New, Factory Rebuilt, or FAA approved overhauled units. On
turbocharged engines, the turbocharger, wastegate, all controllers, bypass valve and
exhaust system must be replaced with new, factory rebuilt or FAA approved overhauled
units. All engine baffles must be repaired or replaced and all flexible baffle seals replaced.

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9 hours ago, SantosDumont said:

Called Jewell and they said around $17k parts and labor, not including mags since I just IRAN'ed them... seems cheap when the shop down the street wants $34k and a factory reman is $42k.  I think I'ma CB this one and get my prop overhauled too.

Thats why they are being recommended

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19 hours ago, kortopates said:

Jewell is a fine choice, and whom Mike B used on one of his engines. But since you mentioned leaving out Mags,  be aware that Major Overhaul is legally defined term by the FAA that to count as a Major Overhaul, and thus reset  TSMO to 0 in your logs, that we are required to overhaul or replace everything that the manufacturer requires per their documentation. Thus you are likely required to overhaul if not replace the mags. An IRAN of mags doesn't count since its not an overhaul that follows its own parts replacement list. If that's important to you, since its affects resale value, be sure to discuss with whomever does your work exactly what kind of return to service paperwork you'll be getting: IRAN vs Major Overhaul on your engine. An IRAN won't reset the clock on TSMO. 

Here is an excerpt from TCM M-0 Appendix C-2 that covers mandatory replacement parts:

At engine overhaul the starter, starter adapter, alternator, magnetos, and engine fuel system
must be replaced with New, Factory Rebuilt, or FAA approved overhauled units. On
turbocharged engines, the turbocharger, wastegate, all controllers, bypass valve and
exhaust system must be replaced with new, factory rebuilt or FAA approved overhauled
units. All engine baffles must be repaired or replaced and all flexible baffle seals replaced.

Hmm that’s a bummer... they only have like 50 hours on them. 

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As to mag replacement, I would discuss this with Sam or David Jewell.  TCM M-0 Appendix C-2, as referenced above, may not apply to your Lycoming engine.  When I read Lycoming service bulletin 240W, it says replace mag drive bearings and drive cushions (engine accessory case parts) but doesn't seem to specify mag replacement. 

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

Never mind, I had assumed you had the standard IO-360

Sam or Dave may also be able to make suggestions regarding shipping details.

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Expect the shop doing the OH will have a shipping crate...

Expect your installing shop will have a shipping crate...

How to handle owning an extra set of nearly newly OH’d mags... that’s an interesting challenge

  • The OH shop is expecting to OH the existing mags...
  • It would make some sense to OH a worn pair of mags...
  • Getting The extra pair of mags comes with its own challenges...
  • How about adding an E-mag to the equation..?
  • Consider keeping any of the parts coming out of the existing mags for spares... if you have spares, you’ll never need them... :)
  • having spare mags that will sit on a shelf for years... and may even get obsoleted by the new mag technology...

Tough choices...

PP thoughts only, not a mechanic...

Best regards,

-a-

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2 hours ago, SantosDumont said:

Anyone know how to ship the engine? Reading through the manual and its mentioning protective plugs, but I don’t see part numbers for them. Also is there a standard shipping crate for aircraft engines?  Where do I get that from?

The shop taking out the engine should have a couple behind the hangar. If not build your own. Only takes a few hours and $50-100. 

The cheaper shops are not providing the same services as some of the more expensive ones. You get what you pay for. I personally like having lots of options to choose from. 

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36 minutes ago, MIm20c said:

The cheaper shops are not providing the same services as some of the more expensive ones.

While this is very often true, in some cases it isn't.  Sometimes the lower price points to a father and son operation with low overhead, and you can still expect to receive personalized quality service. 

BTW, there are 2 unrelated shops in the greater Memphis, with similar names, that can each deliver a quality O/H.  I've used Sam & David Jewell since 1995, including 22 Mooney annuals, and can endorse them without reservation.  http://www.jewellaviation.com/overhauls.htm

However, there's also John Jewell at Holly Springs MS.  He's done some cylinder work for me in the past, and also delivers quality work.  http://www.johnjewellaircraft.com/

I mention John's shop since, although there's not relationship between the two, I can see where someone might get confused when referring to "Jewell" aviation in the Memphis area.

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  • 2 weeks later...

Anyone ever seen something like this... we tested hot/cold and got low compression readings... the lowest was 47.  Two weeks go by gathering quotes for overhaul and just for funsies and to double check before I drop $20k, I bought my own compression tester.

Tested it my self, lowest reading I got was 68.  Called my mechanic over, he tests with his tester and his readings are higher than mine...

So we got out the borescope and took a look.  Some pitting, a couple scrapes but nothing horrendous.  Wondering what went wrong or what changed that we’re getting such drastically different measurement.

Been doing oil analysis for the past two years, and everything is reporting normal.  So wondering what to do now... just keep flying it?  Go ahead with the overhaul?  The CB in me says just keep going, but the risk adverse part of me says overhaul on a TBO engine isn’t a bad idea.

Edited by SantosDumont
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2 hours ago, SantosDumont said:

Anyone ever seen something like this... we tested hot/cold and got low compression readings... the lowest was 47.  Two weeks go by gathering quotes for overhaul and just for funsies and to double check before I drop $20k, I bought my own compression tester.

Tested it my self, lowest reading I got was 68.  Called my mechanic over, he tests with his tester and his readings are higher than mine...

So we got out the borescope and took a look.  Some pitting, a couple scrapes but nothing horrendous.  Wondering what went wrong or what changed that we’re getting such drastically different measurement.

Been doing oil analysis for the past two years, and everything is reporting normal.  So wondering what to do now... just keep flying it?  Go ahead with the overhaul?  The CB in me says just keep going, but the risk adverse part of me says overhaul on a TBO engine isn’t a bad idea.

At the very least you could now fly it to Jewell and have them do the remove, rebuild and re-install.

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3 hours ago, SantosDumont said:

Anyone ever seen something like this... we tested hot/cold and got low compression readings... the lowest was 47.  Two weeks go by gathering quotes for overhaul and just for funsies and to double check before I drop $20k, I bought my own compression tester.

Tested it my self, lowest reading I got was 68.  Called my mechanic over, he tests with his tester and his readings are higher than mine...

So we got out the borescope and took a look.  Some pitting, a couple scrapes but nothing horrendous.  Wondering what went wrong or what changed that we’re getting such drastically different measurement.

Been doing oil analysis for the past two years, and everything is reporting normal.  So wondering what to do now... just keep flying it?  Go ahead with the overhaul?  The CB in me says just keep going, but the risk adverse part of me says overhaul on a TBO engine isn’t a bad idea.

Overhauling based on an emotional concern isn't necessarily the wisest course of action either; especially from a reliability standpoint. TBO is only one parameter. Calendar time can have more importance. But much better to decide based on the health of the engine. Compression test data is notorious for going up and down and for being an unreliable indicator of cylinder health. So good for you for borescoping the cylinders. But still that's only looking at the cylinders. Even if some cylinders need work, this doesn't mean an engine overhaul is really necessary. Cylinders are changed daily without overhauling. Given the expenses and risks you are rightfully concerned with, you owe it to yourself to read to Mike Busch's book on Engines available at Amazon. That will give you sound guidance on how to better decide when to overhaul. Mike has a third book coming out soon addressing aircraft ownership as well.

Anyway, I am only suggesting this because i really believe you'll feel empowered and much more comfortable about delaying engine overhaul till factors discussed in Mike book are really suggesting its time to overhaul, and not just based on some cylinders that are easily repaired or replaced.

see https://www.amazon.com/Mike-Busch-Engines-maintenance-troubleshooting/dp/1718608950/ref=sr_1_1?keywords=engines+book+by+Mike+busch&qid=1561608948&s=gateway&sr=8-1

Edited by kortopates
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One thing I learned about TCM and compression data...

They are not as consistent as Lycoming is....

Definitely read up on TCM compression numbers, and challenges...

OH decisions based on cylinder compressions is technically goofy... anyone that has topped their engine with new cylinders gets great compression data... the engine might have 3000hours and is fully worn out...

anyone that needs new cylinders because they ran them hard and hot... will have low compression numbers at 1khours or less... but the bearing clearances on the crank are still good for a couple more thousand hours...

Cylinder wear is on a different track than engine wear... engine OH isn’t well determined by cylinder compression...

TCM cylinder compression is subject to ring alignment... random day, funky compression numbers...

I spent a fair amount of research learning about TCM compression numbers... while looking for a Missile.

Fortunately we have better tools now... we can actually get pics down the cylinder walls and great views of pizza images on the valves...

What could be better than that...  :)

Follow what people do that fly beyond TBO... they collect a lot of data... oil analysis is a good one... when bearings wear, they leave tell tale signs... when the really wear you can use a micrometer to measure the teaspoonful of bits... 

Save the dough wisely...

know that an OH’d engine comes with its own bag of challenges...

All stuff to look forwards to...

PP thoughts only not a mechanic...

Best regards,

-a-

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On 6/26/2019 at 8:41 PM, SantosDumont said:

Anyone ever seen something like this... we tested hot/cold and got low compression readings... the lowest was 47.  Two weeks go by gathering quotes for overhaul and just for funsies and to double check before I drop $20k, I bought my own compression tester.

Well not relevant now that I see where you are at (I am just reading whole thread now), I would have been in the why overhaul a motor because of 2 bad cylinders camp.  

$17K seems a little off on the quote as well for a major on a six cylinder turbo charged engine.  Parts and machining alone has to come pretty close to that.  Smoking good deal but read all the fine print of what you are getting.  

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  • 2 weeks later...
On 6/28/2019 at 5:05 PM, M20F said:

Well not relevant now that I see where you are at (I am just reading whole thread now), I would have been in the why overhaul a motor because of 2 bad cylinders camp.  

$17K seems a little off on the quote as well for a major on a six cylinder turbo charged engine.  Parts and machining alone has to come pretty close to that.  Smoking good deal but read all the fine print of what you are getting.  

It's an IO-360-ES, so not turbo'ed.  Jewell actually called me back and said ~$18k for parts, ~4k for labor. 

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This has been the worst annual so far.  I feel like I don't have any confidence in my mechanics opinion on my engine.  I read Mike Busch's book and watched a bunch of his videos and feel conflicted about engine mortality after overhaul.  It seems better to keep running something that hasn't shown me any signs of distress until a bad compression check.  

Also I bought my own borescope.  I rotated the prop though and what looked like pitting disappeared... seems like it was just oil on the cylinder wall.  I'm not sure my mechanic knows what to look for considering he doesn't own a borescope, we had to go borrow one.  He's pretty old school and about to retire.  But I'm not really sure what I'm looking for either other than no marks on the cylinder walls and discolored exhaust valves.

I'm probably going to have to get a second opinion on this and gather a lot more data points.

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If it’s not making metal, runs smooth, and making normal power....   not much reason to worry.   Just scope your cylinders at each oil change and make sure you’re valves are seating nicely.   Those erroneous compression numbers can come from deposits on the valve seats.   If that’s the case, you’ll want to lap the seats and ream the guides.

Do you run ROP with low power settings much?

 

Edited by Browncbr1
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5 hours ago, Browncbr1 said:

If it’s not making metal, runs smooth, and making normal power....   not much reason to worry.   Just scope your cylinders at each oil change and make sure you’re valves are seating nicely.   Those erroneous compression numbers can come from deposits on the valve seats.   If that’s the case, you’ll want to lap the seats and ream the guides.

Do you run ROP with low power settings much?

 

Agreed and lapping the valve & seat and reaming the guides can all be done in-situ without pulling the cylinder. Sure worth a try.

Pulling a cyl for a compression of 47/80 isn't even recommended by TCM in the first place (although close, but probably about 5 psi still in the acceptable range depending on the master orifice leak rate at the time - typically ~42psi) - see TCM's excellent guidance now in M-0 or previously in SB03-3

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