New engine installation + test run + break-in

[Tommy]

Hi guys!

I had been hibernating for a while due to busy work and the fact that my J's engine is getting an overhaul after a "small" incident. Now the work has finally completed with the case and 3 cylinders all in pristine condition (a 1000-hour never overhauled case), it's time for the installation work! I have also ordered new engine Lord mount as there is approx one inch droop of the prop compared to the cowl.

This is probably has been asked and answered before but I would really appreciate some tips and things to watch out for when it comes to

1) putting the engine back! My engine workshop - one of the best in Australia if not the best (albeit slightly more expensive) - suggested few things: 

please also remember that if these rocker hat screws are disturbed at anytime, that they will then simply need another coating of Loctite thread locker applied to these screw threads to simply aid them to hold tight properly.  Plus the usage of Dow Corning 736 is also very handy to use on the exhaust gaskets as well & use it to simply form a nice bead around the inner circle of the respective exhaust gaskets on both sides & also then let it all tack off for around 15 odd minutes to then form a type of o-ring to simply enable it to have more body to it all (see photos attached). Plus you also need anti-seize applied to the exhaust nuts & then these nuts also simply need to be check tightened after a run as well.....Also keep in mind to use the likes of this commercially available Dow Corning 736 high temperature sealant to seal up all of your engine related baffles as well to simply enable them all to form a perfect seal.....

 

2) how do you correct the engine droop? 

 

2) how do you do your ground test and your first test flight?

3) how do you break in the engine? run hard and stay low for 25 hours!! 

4) will it be safe to fly 4 hours in one go back to my home airport after the initial tests (probably 3 to 4 hours) on the same day?

 

Thanks guys!!

 

Big shout out to Clarence M20Doc for giving me lots of extremely valuable info!

 

Tommy

[jetdriven]

Don't use that Dow Corning sealer on the exhaust.  It's only good for 600 degrees intermittent.  What it will do is burn out then you get an exhaust leak and it torches the machines exhaust port face.   Just use the no-blow style gaskets.

 

run it only long enough to check for leaks while decowled, 2 minutes max. Then cowl it up quickly, taxi to the runway and take off without messing around. . I flew 2 hours circling the airport at full bore, then took a trip to Dallas at 70-85% power and very rich.  

Edited November 4, 2015 by jetdriven

[Andy95W]

My answers will be bold underlined.

please also remember that if these rocker hat screws are disturbed at anytime, that they will then simply need another coating of Loctite thread locker applied to these screw threads to simply aid them to hold tight properly.  

I have never used loctitie on rocker cover screws, just,star lock washers.  If you use the orange silicone gaskets, they will never leak and they will squeeze enough to help provide tension to the screws.

Plus the usage of Dow Corning 736 is also very handy to use on the exhaust gaskets as well & use it to simply form a nice bead around the inner circle of the respective exhaust gaskets on both sides & also then let it all tack off for around 15 odd minutes to then form a type of o-ring to simply enable it to have more body to it all (see photos attached). 

I have never and would never use this sealant on exhausts.  I agree 100% with Byron's answer above.

2) how do you correct the engine droop? 

Don Maxwell explains all of this from his website:

http://www.donmaxwell.com/publications/MAPA_TEXT/Alining Engine Using Shims/ALIGNING_YOUR_ENGINE.HTML

 

 

2) how do you do your ground test and your first test flight?

I would do exactly what Byron said, above.

 

3) how do you break in the engine? run hard and stay low for 25 hours!! 

Do exactly what Lycoming says to break in your engine.

4) will it be safe to fly 4 hours in one go back to my home airport after the initial tests (probably 3 to 4 hours) on the same day?

Yes, assuming everything checks out.  Your engine will actually appreciate the good, long, 4 hour run at a high power setting.  Just keep an eye on your CHTs and keep them under control with fuel mixture.

 

 

[Guest]

Hello Tommy,

Glad to hear that your engine is ready. I'm assuming the your engine overhauled carried out the initial run in a test cell and not in your plane.  I would not fly it unless it has had the proper procedures followed.  Below is the link to the Lycoming breakin procedure.

http://www.lycoming.com/Portals/0/techpublications/serviceinstructions/SI 1427C (12-29-2010)/Lycoming Reciprocating engine Break-In and Oil Consumption.pdf

Many people have many versions of this procedure, I've followed those of Lycoming and TCM as applicable and never had trouble.  Proper caution would call for staying close to or over the airport until the engine is proven.

 A while back one member here had an engine failure on a freshly repaired engine on the first flight.  

Clarence

[PTK]

Even though my teacher told me there's no such thing as a stupid question here is a...stupid question: 

Is there a good reason why the engine manufacturer or oh shop doesn't break in the engine before shipping it? Sell it already broken in? Why is this function left to the pilot/owner? It seems to me they could easily just run it on their instrumented stand under a controlled environment for a day or two and break it in. No?

 

Edited November 5, 2015 by PTK

[KSMooniac]

I think there are two factors. First is proper cooling, which is difficult to achieve on a static stand. Second is the time involved...you'd be paying for another 10-30 (?) hours of shop time, plus overhead for the test cell.

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[carusoam]

There is one rewarding part of the break in procedure...

You get to fly fast and see the world up close!

Additional Data points: (based on my experience)

1) the factory reman engine from Continental is run on a test stand first.

2) Then shipped to your shop for mounting.

3) your shop takes on the high risk, first flights. Low altitude, high MP, circling the airport expecting a problem.

4) the next few hours are a blast.  High MP, mixing RPM at low altitudes.  Because that is what is required.

5) Breaking in the cylinders requires high MP and altering the RPM over a period of time.  This keeps from wearing in a step in the wall of the cylinders.  If a step were to form, the rings would be broken trying to traverse the step later on.

6) Cold days are good for MP and cooling.

For the break-in flights it is good to bring somebody along. There is a lot to keep track of beyond the normal flight routine.  I used some of the best Mooney CFIIs in my area to keep track and oversee the whole thing.

Time seems to compress when traveling at full Mooney speeds.  It was easy to to change engine settings as we flew past landmarks on the way out and back instead of watching the clock the whole time.

First flights, take your mechanic, or let him fly it while you watch from the ground.

Longer flights, take your CFII.

Keep your CHTs low,

-a-

 

Edited November 5, 2015 by carusoam

[cliffy]

Do exactly what 1395 and M20doc say. I also follow the engine makers proven program and have never had an issue. 

You will be glad when you do.

[aaronk25]

I'm convinced a majority of the cylinder break in happens on the first take off and climb. With that do whatever you can to keep the cylinder assembly as cool as possible. 2 items for sure 1. Full cowl flaps and climb at a higher IAS maybe 110-120kts.

A lot of people screw up new cylinders by overheating the rings and cylinder walls which glazes them and the result is really high oil consumption and oil darkening blow by for the life of the cylinder(s).

Don't get it hot on the ground either during run up ect.....

Just my thoughts the others have very valuable info to add as well.

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[jetdriven]

You may be over-temping the rings even with normal CHTs as well. The cylinder barrel has a lot of friction and the rings may have elevated temps until break in is complete 

[Shadrach]

I live in the low country so 2500' for engine break in was very doable.  I did my break-in in March so weather was cool and my break-in DA was likely close to SL.

Engine Preheated 

Spun the engine sans plugs until oil pressure was noted (IIRC, it was in the top of the yellow on just the starter).

Checked for leaks. 

Installed plugs, started the engine. OP in the green, quick control check, shut down

Checked for leaks

reinstall cowl, verify CFs open and full travel

I again verified mag, prop and mixture continuity during taxi

I informed ground of what I was doing and was cleared for take off upon calling the tower

I lined up, held the brakes and did a full power run up for 10-15 secs; everything was as it should be, so I released brakes. 

Full power, Full rich, shallow climb.

I flew the first hour at 2500msl over the airport at WOTRAO ~15LOP. This turned out to be the setting that put my hottest CHT in the 360 range, so that's where I ran. The second hour was the same method (just lean enough on the lean side of peak to keep CHTs under 370) but with RPM varied between 2400 and 2700.

land, check for leaks. Check the oil.

I did 3 more hours of high power LOP and drained the oil. 

The engine displayed good oil control and temps from that point forward.

Not making any recommendations, just saying what worked well for me.

Edited November 5, 2015 by Shadrach

[Guest]

I live in the low country so 2500' for engine break in was very doable.  I did my break-in in March so weather was cool and my break-in DA was likely close to SL.

Engine Preheated 

Spun the engine sans plugs until oil pressure was noted (IIRC, it was in the top of the yellow on just the starter).

Checked for leaks. 

Installed plugs, started the engine. OP in the green, quick control check, shut down

Checked for leaks

reinstall cowl, verify CFs open and full travel

I again verified mag, prop and mixture continuity during taxi

I informed ground of what I was doing and was cleared for take off upon calling the tower

I lined up, held the brakes and did a full power run up for 10-15 secs; everything was as it should be, so I released brakes. 

Full power, Full rich, shallow climb.

I flew the first hour at 2500msl over the airport at WOTRAO ~15LOP. This turned out to be the setting that put my hottest CHT in the 360 range, so that's where I ran. The second hour was the same method (just lean enough on the lean side of peak to keep CHTs under 370) but with RPM varied between 2400 and 2700.

land, check for leaks. Check the oil.

I did 3 more hours of high power LOP and drained the oil. 

The engine displayed good oil control and temps from that point forward.

Not making any recommendations, just saying what worked well for me.

Ross,

I can can not agree with cranking the engine to establish oil pressure, the fastest way to destroy a camshaft possible.  The engine should be lubricated using an external pressure pot connected to the oil gallery on the front right side of the engine behind the starter ring gear.

Clarence

[Tommy]

Thanks guys for all your advice!

Yes I did find it interesting about the sealant over the exhaust so I will probably leave it for the time being.

I will probably find pressure pot to feed the oil then drag the plane all the way to the holding point then start the engine do a quick run up then fly for 2 hours per Ross'method! Luckily the airport it is at is a very quite GA airport with little traffic and no tower (but a paved runway long enough to land a 747!!).

Can't wait to take to the sky with a new engine. The cam shaft / lobe was toasted in my last one and the shop estimated that I might had lost 20% of HP!

[Shadrach]

Ross,

I can can not agree with cranking the engine to establish oil pressure, the fastest way to destroy a camshaft possible.  The engine should be lubricated using an external pressure pot connected to the oil gallery on the front right side of the engine behind the starter ring gear.

Clarence

I wish I had been in contact with you then. That was my mechanic's instruction. So even with the thick engine assembly lube used during assembly you think I prematurely aged my camshaft spinning it for 3-5 secs at what I'm guessing was ~200 rpm. Is there a chance the builder lubed it before it left his facility? 5 years and 500 hours and it's running beautifully.

Edited November 6, 2015 by Shadrach

[Tommy]

I just asked my mechanics shop and he doesn't have a engine oil pressure rig to pump the oil but the engine shop had tested the engine for 3 hours so should have the engine lubricated and oiled? 

[ArtVandelay]

I wish I had been in contact with you then. That was my mechanic's instruction. So even with the thick engine assembly lube used assembly, you think I prematurely aged my camshaft spinning it for 3-5 secs? Is there a chance the builder lubed before it left his facility? 5 years and 500 hours and running beautifully.

I find it hard to believe the engine doesn't get manually turned over by engine shop after assembly to check it and is bathed in oil before its first start.

[Guest]

It's not a matter of turning the engine over a few times during assembly. Its cranking the engine to establish oil pressure once installed in the airframe.  After the engine has been run by the engine overhauled, any prelude is gone and the only thing protecting the cam and lifter faces is the residual oil from the initial run.  Depending on how long the engine has been sitting there may be virtually no oil film left.

The cam and lifters are lubricated by excess oil being thrown from the crankshaft when the engine starts and oil pressures is established, the sooner oil pressure is established the sooner the cam gets oil.

There are commercially pressure oilers, if you can't get one you can build one from a one gallon pressure painting pot and some hose and fittings available from Harour Freight or similar stores.

Clarence

[Shadrach]

 

It's not a matter of turning the engine over a few times during assembly. Its cranking the engine to establish oil pressure once installed in the airframe.  After the engine has been run by the engine overhauled, any prelude is gone and the only thing protecting the cam and lifter faces is the residual oil from the initial run.  Depending on how long the engine has been sitting there may be virtually no oil film left.

The cam and lifters are lubricated by excess oil being thrown from the crankshaft when the engine starts and oil pressures is established, the sooner oil pressure is established the sooner the cam gets oil.

There are commercially pressure oilers, if you can't get one you can build one from a one gallon pressure painting pot and some hose and fittings available from Harour Freight or similar stores.

Clarence

I picked my engine up from the the builder the day after it was assembled. I had it hung and running within about two weeks of reassembly. I followed the rebuild process very closely and hung the engine myself under supervision. Anyway, I will discuss this with the IA that told me to do it. Everything has been great so far and oil analysis has been positive. 

[Tommy]

Yo Clarence, do you have a photo of the pressure oiler that you use? And how do you use it?

Thanks

ps. My engine was tested run 1 week ago and will be run in about 3 days time.

[ArtVandelay]

It's not a matter of turning the engine over a few times during assembly. Its cranking the engine to establish oil pressure once installed in the airframe.  After the engine has been run by the engine overhauled, any prelude is gone and the only thing protecting the cam and lifter faces is the residual oil from the initial run.  Depending on how long the engine has been sitting there may be virtually no oil film left.

The cam and lifters are lubricated by excess oil being thrown from the crankshaft when the engine starts and oil pressures is established, the sooner oil pressure is established the sooner the cam gets oil.

There are commercially pressure oilers, if you can't get one you can build one from a one gallon pressure painting pot and some hose and fittings available from Harour Freight or similar stores.

Clarence

But that would be the case for any engine that was sitting, I don't understand how a new engine would be destroyed?

My point was that the new engine would have had same oil left on it as our engines when we leave them sit.

[Guest]

 

But that would be the case for any engine that was sitting, I don't understand how a new engine would be destroyed?

My point was that the new engine would have had same oil left on it as our engines when we leave them sit.

 

In the past it was quite common (as Ross pointed out) to install an engine, then crank the engine with the starter motor until oil pressure was established. Everything that had no oil in it would be filled by cranking which could take some time, all the while the cam got no oil and what was on the cam and lifter faces is scrubbed off.  

Pre oiling with a pressure pot assures that all systems are oiled and there will be instant oil pressure on start up, a parked engine has had its oil system filled from the last run.

Clarence

[aaronk25]

After 3 weeks of sitting this cam still had enough oil to protect it for the first few seconds until spash oil can reach the lifter/cam.

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[N601RX]

I used a cheap pump up sprayer from Lowes for preoiling. It would give me about 65psi of pressure.  I put a T in the oil gauge line and was able to push oil in from there.  I was able to get oil to go up through the pushrods into the cylinder rocker area by doing this. My engine was field overhauled with my IA's help.  We did a very quick run-up to check for leaks and verify full throttle and prop control.  After replacing the cowl we pulled it out to the runway and took off.

The 1st few minutes on a new cam and lifters it is critical that the lifters rotate while going up and down and that the proper wear pattern develops. If it doesn't happen the lifters will never rotate and the cam will not last very long.  A mixture of STP and oil is used as assembly oil for most of the engine, but the cam and lifters use a thick moly grease.

[Tommy]

Thanks guys!

 

Just to a couple of more questions!

1) What fuel burn rate would you plan when running full throttle at say 2000' or below? 

2) how often to do change the prop setting during the break-in flights and how long do you leave it at a certain rpm? And How low do you go to?

Cheers

 

 

[Yetti]

http://www.lycoming.com/Portals/0/techpublications/serviceinstructions/SI%201427C%20%2812-29-2010%29/Lycoming%20Reciprocating%20engine%20Break-In%20and%20Oil%20Consumption.pdf

it does not past well so you need to read it.   I created a little spreadsheet checklist to carry with me