Engine Break In

[Seth]

Hello fellow MooneySpacers:

As many of you know, I recently purchased a 1983 M20J Missile 300 and sold my 1967 M20F.  I have had the engine overhauled as metal was found in the filter during pre-buy, and after determining the orgins of the metal, the decision was made.  It helped with the purchase price, which took most of the sting out.  This was after the test flight, and the plane performed very well (the metal was a shock to the seller, however he also understood what that meant - no one else could test fly the plane without a lot of work done, and therefore he was stuck selling it to me - or probably not get a lot of interest).

I have never broken-in an avaition engine - I'm sure there will be instructions from the engine shop as to proper break-in-procedures, and I'll talk to the mechanics I use at the Freeway MSC in Maryland, but please provide all of us with your expeirence of breaking in a newly overhauled engine, pitfalls, what to look out for, what to do, what not to do, etc . . . Please along with your suggestions note if this is something you have been told/heard about or if you actually broke in the newly overhauled engine yourself.

I do not plan to run LOP at this time, nor do I want any debate on ROP/LOP at this time, though I will entertain thoughts of LOP oppertations probably sometime next year.  I want to break in the engine ROP and learn the aircraft before thinking about LOP opps.  Please do not discuss ROP vs LOP at this time - I'll ask advice on that when I'm ready to see how my new plane will react to it.

The missile has a continental IO-550-A with autolean (it leans, but not a ton on the way up to altitude).  For the first 10 - 25 hours, I don't plan to fly much above 4000 feet.

Thank you all for the collective knowlege regarding break-in-procedures.

Take care,

-Seth

[jetdriven]

generally, limit running on the ground to as little as possible, make sure you have enough fuel flow for takeoff, and fly at a a high power setting  to keep cylinder pressure up (75% or more, and vary it often) for 50 hours or until oil consumption stabilizes.  Do not exceed any temperature limits and as always, 400F is the limit most people use for CHT. It might be close to that until the rings break in.  Do not baby the engine, run it hard, and shock cooling debates aside, try to keep it warm all the way to landing.

 

http://tcmlink.com/fiddefault.aspx?cgroup=MATTITUCK&cpagename=BREAKIN

http://www.pennyanaero.com/pages/break_in_operating

[Parker_Woodruff]

The most important things for break in:

-High Power

-Cool temps

 

You don't wanna hear it, but LOP at high power settings is the best way to break in an aviation engine.  I asked what the story was on the IO-550-A on Beechtalk but didn't get much a reply there either.

If you are set on ROP operations, do as such:

Limit time on the ground.  Do a quick runup.  Don't sit there for an hour.  Take off at full power.  Stay at low altitude where you can make 75% power.  First flight should be about an hour.  Land and check for any major oil leaks/bad things.

Go fly a lot of cross country at low altitude & high power settings.  Again, limit time on the ground as much as possible.  You want your rings to get well broken in.

 

[KSMooniac]

Parker is 100% correct whether you want to hear it or not.  The facts are that you cannot develop high power with cooler CHTs ROP, much less keep the gunk out of the bores while you're trying to seat the rings.  Keeping the CHTs as low as possible while keeping the mean cylinder pressures as high as possible are the two things that will give you a good break-in.  The Advanced Pilot Seminars/GAMI gang have broken in hundreds of IO-550-XXX engines over the years (many of which were HIGHLY instrumented) and developed a great set of recommendations that worked for me (IO-360 Lyc) after I freshened all 4 cylinders.   

1.  Do a quick ground run to check for normal behavior and verify no induction or oil leaks.  Don't waste time on the ground, including after landing.  Use the oil you plan to run, not mineral oil.  (I used Aeroshell 100 at the time)

2.  Do a short 45-ish minute flight in the local area at low altitude/hi-power LOP with the cowl flaps open and then land, de-cowl, check for leaks.

3.  Do a low altitude/hi-power LOP cross-country flight with the cowl flaps open and keep an eye on temps.  If everything is working as it should, the rings will seat within a couple of hours and CHTs should drop.  I did a 4 hour flight and my break-in was finished sometime during that flight, and oil consumption quickly stabilized to something on the order of 1 qt/12 hours.  Change the oil, check the filter.  It shouldn't take 25 or 50 hours to break-in.  

The APS/GAMI crew has done all of us a great service with their research and recommendation, and has the data to back it up which they have shared with the community.  Their test stand and instrumented flight tests are far more sophisticated than what the engine manufacturers have historically done.  Their recommendations make a lot of engineering sense, and have a wonderful track record of clean engines with very long service lives.  Running mineral oil and ROP keeps gunk in your cylinders and will interfere with the break-in.

You don't have to believe anything you read here, but you asked for experiences and wisdom.  You have tens of AMU's in an overhauled engine and you're paying the bills, so I hope you'll open your mind to LOP and do some more research before you run it.  You might consider calling GAMI and getting their recommendations straight from the horse's mouth since they've broken-in more IO-550s than anyone else.  I would also discount whatever any mechanic/service center tells you unless they can explain exactly why their recommendations yield a good result.  Not all mechanics truly understand what is going on inside an engine...

 

[74657]

We broke the engine in my Missile in (has approx. 15 hours on it now) using Aeroshell 100 straight 50W mineral oil.  Changed the oil after 1 hour on the test stand then after 4 hours of flying.  We now have 10 more on this oil change and will change it this next week.  Run at high power settings for an hour or better.  Watch your fuel flows and CHT's.  Equally important is the oil temp/pressure.  If you climb too aggressively in moderately warm weather the oil temp will spike and the pressure will drop as the oil thins.  Oil consumption during the first break in interval was about 1 quart after 2 hours of flying and is now less than 1/2 a quart after 6 hours.

Don't trust what the Continental manual says for fuel flows for the IO-550A.  24.6-25.5 gph is not enough.  We really had to work to get mine up to 28.5 and it is happy there.  Rocket will tell you that 27 is the minimum.  30 would be ideal.  Like I said, I get 28.5 @ 625' field elevation and everything is fine.  Have your overhaul shop (or whoever sets the fuel system) contact Rocket directly for advice.  If you trust the Continental book you are going to have oil temp/pressure/cht issues.  The fuel pump on this engine is goofy and takes some time (or someone with firsthand knowledge if this unit) to get it dialed in.  The autolean feature is pretty slick.  I would say that it takes care of 75-80% of the leaning for you and youll only need to make small adjustments to the mixture to keep it set as you climb and descend.   Good luck.

 

Brandon 

[Parker_Woodruff]

---

[danb35]

Phillips XC is 100% mineral oil (as opposed to Exxon Elite and AeroShell 15W-50, both of which are semi-synthetics).  It isn't single-weight, but it's mostly additive-free.

[Parker_Woodruff]

Quote: danb35

Phillips XC is 100% mineral oil (as opposed to Exxon Elite and AeroShell 15W-50, both of which are semi-synthetics).  It isn't single-weight, but it's mostly additive-free.

[LANCECASPER]

Phillips X/C contains ashless dispersant.

Phillips Type M is a straight Mineral Oil.

Both are 20W-50.

 

http://www.aircraftspruce.com/menus/ep/oil_0phillips.html

[danb35]

"Mineral oil" is very commonly (nearly universally) misused in aviation circles.  Its counterpart is synthetic oil (semisynthetic oil is simply a blend of mineral and synthetic oils).  Whether an oil is mineral, synthetic, or a blend has nothing to do with viscosity or additives.

Phillips XC is a multiviscosity mineral oil with AD additives, but little else.  Phillips Type M is a multiviscosity mineral oil without AD additives.  Exxon Elite and AeroShell 15W-50 are multiviscosity semisynthetic oils (25% synthetic for Elite, 50% for AeroShell, IIRC) with comprehensive additive packages.

Mike Bush's most recent webinar is "All About Oil", and (though I haven't watched it yet) I expect it will go into all this in much more detail.  It's at http://www.eaavideo.org/video.aspx?v=991116417001.

[N601RX]

You need to find out what type of cylinders you have. They could be steel, chrome  (there are 2 types of chrome) nitrided or eci cylinders which I believe are plated with some form of nickel.  The break in procedures are not the same for all types of cylinders.

[jetdriven]

.

[KSMooniac]

I ran my break-in XC flight at ~ 10.5 or 11.0 GPH, LOP at 3500'.  This produced enough power and kept all of my CHTs below 360 IIRC (cowl flaps open too, spring time temps).  LOP settings keep a nice, broad pressure trace instead of sharp pulses with ROP settings.  That characteristic in addition to not dumping excess fuel and lead into the chamber are primary reasons why a LOP break-in gives superior results to a ROP break-in.

[Seth]

Update: 

Thank you for the information - The engine ran on a test stand Friday and should have arrived today (may be there tomorrow) for the intallation on the Missile.  I'll see what procedures they reccomened.  I want to make sure to not void the warrenty, but I will take in all the advice you provided.

As for the LOP vs ROP break in - there is a lot to be said for LOP ops - I've been researching a lot - so - point taken.  I'm pretty sure Bolduc (the engine shop) is going to reccomend ROP break in.  Regardless, high pressure, watch the temps, and no short flights. 

What would you consider a "short" flight to avoid during the break in - nothing less than 40 min?  60 min?  2 hours?

Again, thank you.

-Seth

[KSMooniac]

If the shop gives you a recommended break-in procedure, ask how and why they developed such procedures.  Answers such as "we've always done it this way" indicate they don't really understand what is happening inside the cylinders.  If they have a warranty, ask how they check for engine operations if that is somehow a condition of the warranty.  

1 short flight (30-45 minutes) is prudent for a function and leak check before setting off on a long XC flight.  You'd hate to be pumping oil out and only find out after you run out of oil!  Just minimize the ground time as much as you can, both on taxi out and taxi back.  Keep the cowl flaps open if you have them (I'm not sure on the Missile).

I'd still break it in LOP.    It has worked extremely well for me, and countless others that have been enlightened in the last 10+ years.

[Seth]

Yes, one short flight is prudent and planned - I agree with that 100%.  Check for oil leaks.

The Missile does not have cowl flaps.  I had an JPI EDM 830 installed and will watch the temps very closely.  First long flight will be from MN to MD, so that should account for qutie a bit of the initial break in period.

That first long flight will be after at least an hour to an hour and a half flight with Bruce Jaeger for familiarizaztion purposes with the new systems and procedrues. 

Take care,

-Seth

[74657]

You will not be disappointed with the 830!  Keep the nose low and make sure not to fly too much over 120kts on climbout and you will be fine.  Rocket did their homework with this STC and cowl flaps are not needed.  I put 20 hours on this week and never once got my CHT's over 400 while holding 120kts on climbout.  If you keep the CHT's cool the oil will never get over 220.  At cruise, mine runs about 186 with OAT's in the 60's.

After 30 hours my oil consumption is virtually nothing.  I only fill mine to 10 quarts though.  If I top it off at 12, 2 of the quarts winds up on the belly in short order.

Congrats on your Missile.  You're going to love it.  Feel free to stop @ BEH on your way home if you have time.

[Shadrach]

A lot of good advice here and some less than optimal in my opinion. Yes, I agree that LOP is the most optimal way to break in an engine and will produce the best physical result (but the reason is for another thread). That being said, ROP has worked for ever and will continue to work if done properly. I would rather not see 380 df CHTs as heat will not in anyway hasten the process. Run it at low alt and run it hard. Vary RPM after the first hour or two. Chrome cylinder/rings will take considerably more time (20-30hrs) to break in when compared to nitrided steel, which ought to be done in 5 to 10 hours. 

Something that has not been said... I would pull the plane out and do the run up and leak check and then let it cool (preferably over night or all day). The next run should be done with as little taxi/low power operations as possible. Taxi out (you can check mags and prop during taxi [i always do] if you want or do a quick run up). Take off and fly at TPA + 500 over the airport for the first hour. Shoot for 200ROP and go richer if need be to keep CHTs as cool (as in not 380) as practical. 

[Parker_Woodruff]

Have fun, and congrats again! Say hi to Tim and Bruce for me.

[jetdriven]

IM with Ross, make one short flight to check for leaks, then a hour over the airport circling at 200 knots before setting off.

[rocketman]

I have 10 hours on my Victor Black II Edition TSIO-520-NB on my rocket and the oil has stabilized running ROP within 10 hours. The company in CA told me not to run LOP and to switch to Phillips XC mineral oil with AD to be sure the engine has broken in. To run a semi-synthetic will stop the break in process at 10 hours and  was not advised in case the engine was not completely broken in but yet benefit from the multigrade oils here in the upcoming cold months in Kentucky.

 

After another 25 hours running with Phillips and if there is insignificant oil burn, I plan to switch to Exxon Elite as several articles have alluded to that this oil is the best for those of us who don't fly too often. Better anti-corrosion protection.

[jetdriven]

According to some sources, Philips XC mixed with Camguard is better than ony other combination.  Its all out there.

[fantom]

I believe Phillips XC + Camguard is the cheaper good choice, while Exxon Elite is a somewhat more expensive good choice. I've never seen any data comparing these two products.

Wounder if Exxon Elite + Camguard would be even a better good choice.

[Shadrach]

Edward Kollin who was one of the principal developers of Exxon Elite and is the developer of Camguard has stated numerous times that Phillips XC is as good or better than any base stock available for aircraft. For maximum protection he reccomends Camguard and Phillips XC. IIRC, he said that combining Exxon Elite (which he claims is a good stand alone product) would improve its corrosion protection slightly, but that it would be no better than using Phillips XC, but at a higher cost.

 

[bd32322]

My engine finally got done today and its going to ship back from zephyr prolly in a week or so. Cant wait to get up in the air behind a freshly overhauled engine.

One question however - I am thinking of phillips xc 20w-50 mainly because it has no friction modifiers, but it has the AD stuff to keep gunk off engine parts and hold them in suspension.

 

Good idea? Lycoming and my mechanic think it should be straight mineral oil and non-AD oil - dont know what zephyr thinks - I guess I'll find out soon