'79 M20J overhaul recommendations

[kris_adams]

Hi Everyone,

I have lost confidence in my current engine (21 years since overhaul, increasing oil leaks, "odd" sound on last flight, etc). The plane is a '79 with approximately 2950TT, 1200SMOH(1 overhaul on engine). I would classify my flying style as “easy” IFR so I am looking for a stable engine that I do not have concerns with.

This is my second plane and I didn’t have to major the engine on the first plane so I am looking for advice from the group. As of right now I am leaning toward Zephyr engines or another engine shop (can’t remember their name right now). The plane is at Cole Aviation and he will be removing/re-installing the engine and he is happy to send it to the engine shop of my preference.  Joey is also providing advice but due to the expense, I want to make sure I am as informed as possible.

-plane has all new hoses that are <1 year old

-Plane has JPI730 already (will keep for now, new probes within 18 months)

-Plan to replace vacuum pump

-Plan to go with GAMI injectors (don’t currently run LOP but would like the option)

-Exhaust: replace, repair, re-install if it checks out?

 

What else should I be considering?

 

Thanks in advance!

Kris

[74657]

Might as well thrown on a new set of engine mounts.  Strip/inspect/repaint engine mount.  You might want to have the alternator replaced/freshened.

Prop governor overhaul - 700ish bucks.

My engine overhaul ended up costing me an extra 6K for a new crankshaft (rust/pitted).

Depending upon how much you fly and your long terms plan for the airplane you might want to consider nickel cylinders.  I did.

I would budget an extra 25% for unknowns.  Stuff always comes up.

[jetdriven]

 Baffle seal strips. Reinforce the upper cowl with fiberglass and epoxy.  Alternator or starter if they are old or giving out. Make sure the overhaul includes overhaul of the RSA-5 fuel injection. TBO on it is also 12 years, or engine overhaul.  Mine wasnt done at the engine overhaul and it had to be done a year later when it wasnt running right.

Get factory new steel cylinders and, opinions vary, but I would use only a new camshaft and new lifters.

Oh, and that Bendix D2000 dual mag... Go through that one if its been a while.

[Shadrach]

I think you've gotten some good advice on OH. So I'm gonna play "Devils Advocate"...

1200hrs is mid time for an angle valve lyc. 

Has the plane been hangared it's whole life?

How many of the 1200 did you put in the engine?

Compressions?

Have you been doing oil analysis?

How does it perform?

Odd sound???

Many...and I mean MANYYYYYY....IO360s have done 3 time the hours and twice the calander time that yours has. Why so quick to pitch it?

Confidence is a big deal, but if it's not based in reality, it's not really good for anything but your disposition.   You've said nothing of consequence about the engine other then you don't trust it. I'm not saying your wrong, but without some evidence as to why, your feelings seem to be based in emotion...

You've a few recently replaced wear items as well, so it looks as if your trying to keep up with MX. I hate seeing fried 30 yr old hoses, but it is oh so common...

You may already know this, but a new engine can cause major headaches as well. All things being equal, I'd feel safer behind a 1000hr engine than a 100hr engine.  This column has some pretty interesting ideas and stats on catastrophic engine failure. According to the source in the article, the first 4 years and 499 hours show the greatest likelihood of a failure.

http://www.avweb.com/news/savvyaviator/savvy_aviator_45_how_risky_is_going_past_tbo_195241-1.html

[Parker_Woodruff]

You want Zephyr Engines if you're going to overhaul.

[N601RX]

Ask what parts will be replaced based on the price they quote.  The prices for IO360 that most shops quote are based on reusing your cylinders and cam.  When comparing quotes, just be sure you know what parts are new and what being reused.

[Piloto]

Replace the original starter with the new Sky-Tec, it is well worth  it.

José

[lahso]

Quote: Kris_Adams

...I am leaning toward Zephyr engines or another engine shop (can’t remember their name right now). The plane is at Cole Aviation and he will be removing/re-installing the engine and he is happy to send it to the engine shop of my preference.  Joey is also providing advice but due to the expense, I want to make sure I am as informed as possible.

[danb35]

Have you tried running LOP without GAMIs?  It seems that many, if not most, IO-360s will do just fine without them, and if the engine will run smoothly LOP without them, no need to spend $800 (plus labor).

[jetdriven]

Get one jar for each cylinder so not to mix them up, soak them in acetone overnight, blow dry and reinstall.  Do the GAMI spread test.  Rearrange them to even the fuel distribution.  It worked for us.

[Cruiser]

The engine is 32 years old, it has had only one overhaul 1200 hours ago, the original engine only went to 1750 before it was overhauled. Why?

At 2950 total time, it has very few hours of actual use. What about the mag?, starter? fuel system? electrical? exhaust?

IF confidence is your only concern, do those things that will restore that at the least expense possible. 1200 hours should not be cause for overhaul, find out what is causing the issues and fix them.

IF you are spending overhaul $$ then do the things that will add overall value to the plane. When you consider selling, as a buyer, I would question why the engine was overhauled prematurely. This could be a negative to potential buyers.

[kris_adams]

Hi Everyone,

 

Thanks for all of the great ideas.  Sorry, I didn’t mean to turn this into an “overhaul” or “don’t overhaul” thread.   Without going into details, I’ll just say it seems to have turned into whack-a-mole and every time I fix something, something else pops up.  I plan to keep the plane for the foreseeable future, so I think this is the right decision (for me at least).  YMMV.

 

Here’s what I plan to do:

·         Overhaul at Gann Aviation (same engine shop Tornado alley used to prepare their TN Cardinal which had the same engine as my m20J).  I had numerous people PM me with positive experiences.  I like that I can call and actually get the owner (Carlos, who is an active pilot flying an A36) on the phone.  Since they are close to my MSC, they will pickup and deliver the engine for no additional charge.

·         New/overhaul mags, fuel system, plugs, etc. (unfortunately the dual mag overhaul is a premium right now)

·         GAMI injectors ($600 upgrade)

·         Dowel/O-ring modification (through bolts no longer align the case)

·         Nickel cylinders (overhauled, 1^st run cylinders with 400 hours); only option is steel from Lycoming

·         Vacuum pump-new

·         Alternator-new or overhaul-tbd

·         Prop governor overhaul

·         Sky-tec starter is <2 years old so I think I will stay with it

·         Engine mounts (bushings) replace

·         Engine mounts strip and paint

·         Exhaust system tbd (I think mine was redone recently)

·         Oil cooler

·         Still need to address baffles, re-enforce upper cowl

 

Thanks again for all the help.

 

I’ll post some pictures later this week as I’m going to go see the engine disassembled on Friday (another advantage of going with Gann).

 

Kris

 

[KSMooniac]

If you're TBD on the alternator, I'll heartily endorse the Plane Power option.  I put one on last fall after my ol Prestolite cratered, and the only other options appeared to Kelly overhauled, or Kelly new and I don't want Kelly anything on my plane.  Reasonable price, great performance so far.

I'd also skip the GAMIjectors for now and give the engine a try after overhaul when you're convinced you have no induction leaks.  Most IO-360s will run LOP nicely out of the box, so no sense in spending that money until you really know you need them.  

LASAR is a great source for baffle pieces.  You can also get a pre-cut seal kit, or get raw seal stock and cut your own.  

I had my dual mag overhauled last fall and there were still enough parts in the system...hopefully that is still true!

[kris_adams]

Thanks for the idea Scott. 

As far as the mag situation goes, I guess our mags are Bendix which is now owned by Teledyne.  I guess Teledyne is no longer making any parts for this mag, so the existing inventory stock is coming at quite a premium.

Carlos said that Lycoming (with someone?) to develop an alternative, but for now my only choice is to pay the higher price.  Sounds like this premium will be $500-$750.

Kris

[jetdriven]

Quote: Kris_Adams

Hi Everyone,

 

Thanks for all of the great ideas.  Sorry, I didn’t mean to turn this into an “overhaul” or “don’t overhaul” thread.   Without going into details, I’ll just say it seems to have turned into whack-a-mole and every time I fix something, something else pops up.  I plan to keep the plane for the foreseeable future, so I think this is the right decision (for me at least).  YMMV.

 

Here’s what I plan to do:

·         Overhaul at Gann Aviation (same engine shop Tornado alley used to prepare their TN Cardinal which had the same engine as my m20J).  I had numerous people PM me with positive experiences.  I like that I can call and actually get the owner (Carlos, who is an active pilot flying an A36) on the phone.  Since they are close to my MSC, they will pickup and deliver the engine for no additional charge.

·         New/overhaul mags, fuel system, plugs, etc. (unfortunately the dual mag overhaul is a premium right now)

·         GAMI injectors ($600 upgrade)

·         Dowel/O-ring modification (through bolts no longer align the case)

·         Nickel cylinders (overhauled, 1^st run cylinders with 400 hours); only option is steel from Lycoming

·         Vacuum pump-new

·         Alternator-new or overhaul-tbd

·         Prop governor overhaul

·         Sky-tec starter is <2 years old so I think I will stay with it

·         Engine mounts (bushings) replace

·         Engine mounts strip and paint

·         Exhaust system tbd (I think mine was redone recently)

·         Oil cooler

·         Still need to address baffles, re-enforce upper cowl

 

Thanks again for all the help.

 

I’ll post some pictures later this week as I’m going to go see the engine disassembled on Friday (another advantage of going with Gann).

 

Kris

 

 

[Shadrach]

Can you get remaned cyl for an angle valve lyc? I thought your options were field OH'd or factory new...

[KSMooniac]

If the jugs are first run AND you're doing a field overhaul, then I'd certainly consider having them overhauled by a quality shop.  If you have a known, good set of first run jugs I'd rather take my chances with a shop of my choosing to replace the seats and guides (and valves if needed) and do it precisely enough to get them all centered and happy.  Poor fit from the factories in recent history is why a lot of jugs don't make a full TBO run before needing attention.  You also don't roll the dice with unknown quality steel/heat-treat on the new ones.  Our angle-valve jugs are sole-source Lycoming (~$2k each) so overhauling them in the field can make economic sense ($600-700-ish).  Just another thought...

I'm around 1850 SMOH on mine currrently, but freshened my jugs at 1650 SMOH and plan to keep going until I get some signs that it is time to overhaul.  If I had to do it tomorrow, I'm undecided on field overhaul vs. taking advantage of the current Lycoming pricing that applies on first-run or factory overhauled engines (which mine is) which includes an update to the new roller-cam technology.  I would like to think that is a significant improvement over the old style, but the cynic in me wants to wait and see if Lycoming screwed up the implementation before I take the plunge.  There is still a significant price difference between a typical field overhaul and the Lycoming offer...on the order of 10 AMU I believe.

[Txbyker]

I hate to hijack this thread from Kris but notice a lot of you commenting on the hours and longevity and I have some questions.  I too have an old engine but low hours.  It is a 1987 with 1531 hours and never had a total overhaul.  Previous owner honed the cylinders and got new rings at about 1250 due to one of the rings breaking in flight.  It has good compression, low oil consumption and runs smooth.  I was thinking of an overhaul this summer due to age.  Would you take it to 2000 hours if running good or do you factor in age?

[jetdriven]

i would run it until it shows cause for overhaul, such as Mike Busch says.  Making metal, cracked case, bad cam lobe.  If it needs a cylinder every now and then, give it one.    He practices what he preaches, his 310 engines at one point were 22 years old and were 1,000 hours past TBO.    http://www.avweb.com/news/savvyaviator/187727-1.html

 

[N601RX]

Quote: Shadrach

Can you get remaned cyl for an angle valve lyc? I thought your options were field OH'd or factory new...

[kris_adams]

Quote: jetdriven

i would run it until it shows cause for overhaul, such as Mike Busch says.  Making metal, cracked case, bad cam lobe.  If it needs a cylinder every now and then, give it one.    He practices what he preaches, his 310 engines at one point were 22 years old and were 1,000 hours past TBO.    http://www.avweb.com/news/savvyaviator/187727-1.html

 

[jetdriven]

these are all excellent reading.  

http://forums.savvyaviator.com/articles.html

 

then go read pelican's perch.

http://www.avweb.com/news/pelican/182146-1.html

 

  then go watch Savvy mx videos. 

http://www.savvymx.com/index.php/resources/webinar

[John Pleisse]

Quote: Kris_Adams

Hi Everyone,

I have lost confidence in my current engine (21 years since overhaul, increasing oil leaks, "odd" sound on last flight, etc). The plane is a '79 with approximately 2950TT, 1200SMOH(1 overhaul on engine). I would classify my flying style as “easy” IFR so I am looking for a stable engine that I do not have concerns with.

This is my second plane and I didn’t have to major the engine on the first plane so I am looking for advice from the group. As of right now I am leaning toward Zephyr engines or another engine shop (can’t remember their name right now). The plane is at Cole Aviation and he will be removing/re-installing the engine and he is happy to send it to the engine shop of my preference.  Joey is also providing advice but due to the expense, I want to make sure I am as informed as possible.

-plane has all new hoses that are <1 year old

-Plane has JPI730 already (will keep for now, new probes within 18 months)

-Plan to replace vacuum pump

-Plan to go with GAMI injectors (don’t currently run LOP but would like the option)

-Exhaust: replace, repair, re-install if it checks out?

 

What else should I be considering?

 

Thanks in advance!

Kris

[bnicolette]

I would have to agree with the fact that the next buyer may look at the time when overhauled and seem to think that either the previous owner was not very kind to his/her engine or the engine is a lemon.  I know when I was looking for my airplane, those figures were very high on my priority list.  I fly IMC all the time and I could care less about having an IFR GPS or other gadgetry (well, it wasn't high on my wish list; it would be nice, but other things were much more important), but I did want a sound airplane and engine with great history.  I suppose if you want to major the engine now, a factory reman would be the way to go.  I think a field overhaul may cause you a headache down the road with regards to resale since it is being done very early.  Or not.  Just food for thought.

I have nothing against field overhauls.  My engine was at 1950 hours when the previous owner had a gear up, and that's when they decided to major it (field overhaul with new ECI steel cylinders, etc), I guess in part because the insurance was paying the bill anyhow.  It now has 600 trouble free hours and it is out of that danger period and knowing that it went to TBO previously, I have a lot of confidence in my engine.  Especially with the engine monitor, oil analysis, and periodic compression checks.  We also have a boroscope at work, but I have yet to do that since I bought the airplane.

I know how important it is to have confidence in your engine, but honestly, if you are doing the oil analysis, and nothing has changed with oil consumption or leaks, and you have your mechanic do a compression check and boroscope, I would think your confidence level should be very high.  In order to have a high confidence level again after an overhaul, I would think that you would have to be VERY cautious the first 200 hours you fly.  I'm not sure how much you fly, but for the average GA pilot, that could be 4 years of high caution and lot of VFR days.  Just more food for thought.

Good luck in your decisions.

 

[Shadrach]

So much lore about OH vs reman vs factory new... If the OH'd to specs, it hardly matters who does the assembling as long as they're competent.  The difference in parts is that in a factory OH or reman, is that you have no idea where or how old the reused parts are in your engine are. With a field OH you are reusing crank, cam, connecting rods etc... Factory Reman/OH has a pile of parts that passed as serviceable and that's what goes into your bird.  When we did our field OH 10 years ago, I wanted to reuse as much of our 33 year old (at the time) engine as possible. Why??? because I knew that the metallurgy was sound. I was not liking the possibility of a crank or rod AD...  The factory may offer better support if something goes wrong, and then they might not. I'd take a personally known to me, local engine builder over a parts bin Franken-rebuild any day. If I were buying a used plane, I'd try and find one close to TBO so as to be ready to OH it anyway or low time factory new. I am just as concerned with how it was flown as I am with how it was built. I put 0 credence in the "0 time reman"...