IO-540 Break in oil consumption

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nickpan

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nickpan
I hope this is ok to post this on your forum!

I have an airboat that has a Lycoming IO-540 D4A5 engine on it and we recently did a top end overhaul and i have a question on oil consumption.We have channel chrome cylinders on the engine. Running Phillips 20-50 Type M oil for break in.

We did the initial run in procedure as described in the lycoming overhaul manual, and after that initial hour we noticed around maybe a half a quart of consumption.

Took it and ran it for two hours the next time and tried to keep it up above 75% power for the majority of the run. Engine ran great with the temps where they should be, a little higher than normal on the CHT and plenty of power.

It consumed about 1.75 quarts that run of 2 hours. So in the first 3 hours of running, it consumed just a hair over two quarts.

It has a 12 qt sump and we have filled it to 10 initially, and gauged the consumption off of that level.

Is this normal? I have heard it takes awhile for chrome cylinders to seat compared to steel or other materials. What should i see for consumption from here on out if that is normal?

I hope this is ok to post this on here, i figured you guys would know better than any!

Thanks
 
Not a mechanic but I believe that it is normal for a freshly rebuilt motor to consume a good deal of oil for the first 10-15 hours before stabilizing at a lower consumption rate
 
dell30rb said:
Not a mechanic but I believe that it is normal for a freshly rebuilt motor to consume a good deal of oil for the first 10-15 hours before stabilizing at a lower consumption rate
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Specially the Chrome cylinders.
 
Where is the oil going? I suspect you just blew most of it out the breather. I'd be trying to keep it around 9 quarts..not 12.

It is normal to have higher than normal oil consumption initially, as well. But no IO-540 I've seen will happily hold 12 quarts. In the airplane world it just ends up on the belly.
 
nickpan said:
I hope this is ok to post this on your forum!

I have an airboat that has a Lycoming IO-540 D4A5 engine on it
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Welcome.....

Chrome cylinders are difficult to get the rings seated in.... An airboat lives in a slightly different world then planes. We have to keep close to full power to stay in the air.. In an airboat you can idle around.. DON'T do that.... Run the crap out of it and hopefully in 10 -15 hours the rings will seat and oil consumption will decrease... Jesse gave good advice too.. 12 quarts is too much. The motor will spit out the first 2-3 quarts. Use non detergent oil for breakin and like I said..... Run it HARD,, don't baby it..

Let us know how it went .

Ben.
 
Thanks for all the info!

We filled it to 10 quarts initially, and we did notice a decent about dripping out the breather. We have never filled it to 12, as i have heard the same. We will try to keep it around the 9 mark.

We have been trying to run it as hard as possible, and when we do have to idle, we try to keep it above 1000 rpms at the least, but we try not to do that if we dont have too.
 
nickpan said:
Thanks for all the info!

We filled it to 10 quarts initially, and we did notice a decent about dripping out the breather. We have never filled it to 12, as i have heard the same. We will try to keep it around the 9 mark.

We have been trying to run it as hard as possible, and when we do have to idle, we try to keep it above 1000 rpms at the least, but we try not to do that if we dont have too.
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Take note, some times it requires two or three sets of rings to smooth out a chrome cylinder and be sure you use cast iron rings, never chrome rings in chrome cylinders.
 
We have the cast iron rings in there
 
nickpan said:
We have the cast iron rings in there
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Yup.. We know.. If you had chrome rings in it your question would look something like this.

---------------------------------------------------------------------

Hi.. We topped our motor with chrome cylinders and installed chrome rings, the motor ran about 10 minutes and now has NO compression and shiny, flakey stuff has coated the exhaust ports and filled the muffler.:hairraise::eek:.. :wink2:
 
N801BH said:
Yup.. We know.. If you had chrome rings in it your question would look something like this.

---------------------------------------------------------------------

Hi.. We topped our motor with chrome cylinders and installed chrome rings, the motor ran about 10 minutes and now has NO compression and shiny, flakey stuff has coated the exhaust ports and filled the muffler.:hairraise::eek:.. :wink2:
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Funny thing that..

I know 1, 0-300 that the third set of rings they installed were chrome, on chrome, and they are still running strong after 1000 hours.
 
Tom-D said:
The 2 sets of rings prior had the cylinders pretty much polished.
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I agree that might help the chrome rings from destroying the chrome surface of the cylinders . BUT.. There are a few things wrong with your posts.

1- in post #7 ...you said this to the new guy who came here asking for advice

" Take note, some times it requires two or three sets of rings to smooth out a chrome cylinder and be sure you use cast iron rings, never chrome rings in chrome cylinders. "
__________________
The A&P-IA certificate does not give the holder the ability to see the future.

2- Then you say this ....

"Funny thing that..

I know 1, 0-300 that the third set of rings they installed were chrome, on chrome, and they are still running strong after 1000 hours." __________________
The A&P-IA certificate does not give the holder the ability to see the future


So now the new guys is sitting there scratching his head thinking. Geez ,a FAA licensed A&P with IA authorization is talking out both sides of his mouth.:yes::yikes:.

3- and probably most important, you, as a licensed A&P /IA stated you know of a aircraft engine with a possible safety of flight mechanical issue and doesn't act with due diligence and either reports the defect to the closest FSDO or warn the owner to ground the plane, or both..:dunno:

That is like a A&P/IA walking down the ramp and seeing a wing spar bolt laying under an aircraft and not saying anything to anybody...

Is it legal ? who knows :dunno:

Is it the decent and right thing to do ? Heck NO.. IMHO.

Flame suit on...
 
Keep in mind you can run as low as 2-3 quarts (although I'm not recommending that). I ran my Aztec engines at 6 quarts happily for a thousand hours.

And yes, flog the crap out of it. :)
 
N801BH said:
I agree that might help the chrome rings from destroying the chrome surface of the cylinders . BUT.. There are a few things wrong with your posts.

1- in post #7 ...you said this to the new guy who came here asking for advice

" Take note, some times it requires two or three sets of rings to smooth out a chrome cylinder and be sure you use cast iron rings, never chrome rings in chrome cylinders. "
__________________
The A&P-IA certificate does not give the holder the ability to see the future.

2- Then you say this ....

"Funny thing that..

I know 1, 0-300 that the third set of rings they installed were chrome, on chrome, and they are still running strong after 1000 hours." __________________
The A&P-IA certificate does not give the holder the ability to see the future


So now the new guys is sitting there scratching his head thinking. Geez ,a FAA licensed A&P with IA authorization is talking out both sides of his mouth.:yes::yikes:.

3- and probably most important, you, as a licensed A&P /IA stated you know of a aircraft engine with a possible safety of flight mechanical issue and doesn't act with due diligence and either reports the defect to the closest FSDO or warn the owner to ground the plane, or both..:dunno:

That is like a A&P/IA walking down the ramp and seeing a wing spar bolt laying under an aircraft and not saying anything to anybody...

Is it legal ? who knows :dunno:

Is it the decent and right thing to do ? Heck NO.. IMHO.

Flame suit on...
Click to expand...

I simply said I know there is one running with chrome rings in chrome cylinders, So where did you get the idea I thought it was a good idea? or where I said it was an aircraft engine? some do use the 0-300- in air boat sleds.

OBTW it is not legal, for airworthiness, you must comply with a
FAR 43.13. there is no data approved to use chrome rings in chrome cylinders
 
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thanks for all the info guys. been busy but had it out today again and had a hair over 9 qts in to start with and burned down to about 7.5-8 qts in about 2 hours running. did notice a little out the breather still but not as much this time. so got about 5 hours on it now, still a little ways to go sounds like!

been trying to keep it well over 2000 rpms most of the time, but that can be tough as you get cruisin pretty good and no brakes and run out of water, so were doin the best we can!
 
nickpan said:
thanks for all the info guys. been busy but had it out today again and had a hair over 9 qts in to start with and burned down to about 7.5-8 qts in about 2 hours running. did notice a little out the breather still but not as much this time. so got about 5 hours on it now, still a little ways to go sounds like!

been trying to keep it well over 2000 rpms most of the time, but that can be tough as you get cruisin pretty good and no brakes and run out of water, so were doin the best we can!
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Manufacture a oil recovery system for your breather, might help.

Running high RPM may not help, your prop may not load the engine enough to break it in as we do in aviation.

Do you have a manifold pressure gauge?
 
Mind if I ask...what fuel you running in that engine?
 
Running high RPM may not help, your prop may not load the engine enough to break it in as we do in aviation.

Do you have a manifold pressure gauge?
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We don't have a manifold pressure gauge on the boat. Can you explain why running high rpm may not help, just curious? We have an 84" x 36 pitch two blade wood prop on the boat. Hardest i've ever turned it was about 2750 rpms and there was a ltouch more throttle left to give.


Mind if I ask...what fuel you running in that engine?
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90% of the time we run 91-93 octane in it. 100ll is hard to get out here, especially for an airboat. Most of the airports around here won't let you bring the boat on the property anymore to fill it up.
 
Hang a couple of heavy barbell weights on ropes off the back. Maybe two 20Lbs on 5 ft of 1/4" nylon with a breakaway so it won't damage the transom.

You're gonna get plenty of blowby even with 8 quarts for the first 30 hours or so. make sure your crankcase vent his open, and I would recommend against 90deg elbows in the vent.

Vary your throttle inputs plenty. Hard bursts, then slow down gradually, then a hard burst, then slow down. It'll run anywhere up to redline with decent fuel in it. Once the oil consumption settles down take the weights off and enjoy.
 
I live down in Salt Lake, UT. We've had some luck out at the West Jordan Airport. Others are hit and miss it seems like. So we have just resorted to mogas.
 
nickpan said:
I live down in Salt Lake, UT. We've had some luck out at the West Jordan Airport. Others are hit and miss it seems like. So we have just resorted to mogas.
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Keep in mind corn in fuel is not kind to aircraft aluminum fuel system parts.
 
Tom-D said:
Keep in mind corn in fuel is not kind to aircraft aluminum fuel system parts.
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Tom is 100% correct..... Back in my racing days most of the cars I ran used methanol.... That stuff is corrisive as heck and we had to flush the motors after each race... Ethanol ain't so bad but it still corrodes aluminum ...:eek:
 
Yeah we have a hard time finding ethanol free fuel as well, but we try to get it when we can. There are a few boats out here that have been running on the "new fuel" for a few years now and no ill effects noticed yet, so we keep our fingers crossed.
 
nickpan said:
Yeah we have a hard time finding ethanol free fuel as well, but we try to get it when we can. There are a few boats out here that have been running on the "new fuel" for a few years now and no ill effects noticed yet, so we keep our fingers crossed.
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They will run just fine, the trouble comes when you try to get core for fuel system parts.
 
nickpan said:
Can you explain why running high rpm may not help, just curious?
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What you are trying to achieve is high cylinder pressure. This pressure is able to get behind the piston rings and push them out against the cylinder walls, allowing them to break in. High cylinder pressure is a result of high manifold pressure.

If you were to take the prop off and just run the engine at high rpm, your throttle would not be open very far, your manifold pressure would be low, your cylinder pressure would be low, and your rings would not seat. It takes a load on the engine to allow you to raise the manifold pressure without overspeeding the engine.

Now if your airboat has a prop on it that won't provide the proper load at rpm, you will have a very slow break-in process. So high rpm by itself may not help.

-Skip
 
nickpan said:
....We have an 84" x 36 pitch two blade wood prop on the boat. Hardest i've ever turned it was about 2750 rpms and there was a ltouch more throttle left to give.




.
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My guess is he has the airboat propped just about perfectly..:yes::yes:.
 
Skip Miller said:
What you are trying to achieve is high cylinder pressure. This pressure is able to get behind the piston rings and push them out against the cylinder walls, allowing them to break in. High cylinder pressure is a result of high manifold pressure.

If you were to take the prop off and just run the engine at high rpm, your throttle would not be open very far, your manifold pressure would be low, your cylinder pressure would be low, and your rings would not seat. It takes a load on the engine to allow you to raise the manifold pressure without overspeeding the engine.

Now if your airboat has a prop on it that won't provide the proper load at rpm, you will have a very slow break-in process. So high rpm by itself may not help.

-Skip
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High cylinder pressure (BMEP) comes from load (Torque) and can happen at any RPM.

If the piston can't travel down the cylinder to relieve the pressure the BMEP will rise.

Which occurred first? the chicken or the egg? BMEP will be more harmful at high MAP.
 
Tom-D said:
High cylinder pressure (BMEP) comes from load (Torque) and can happen at any RPM.

If the piston can't travel down the cylinder to relieve the pressure the BMEP will rise.

Which occurred first? the chicken or the egg? BMEP will be more harmful at high MAP.
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I don't disagree. And I am sure you agree as well, that in order to break in a new set of rings, you need to run the engine under load, not just fast idle it.

Too much load/too little rpm can lead to detonation. Too little load, break-in will be prolonged or never happen. There is a happy medium.

-Skip
 
Skip Miller said:
I don't disagree. And I am sure you agree as well, that in order to break in a new set of rings, you need to run the engine under load, not just fast idle it.

Too much load/too little rpm can lead to detonation. Too little load, break-in will be prolonged or never happen. There is a happy medium.

-Skip
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Believe it or not, break in has more to do about ring tension than pressure behind it.

In his chrome cylinders, driving a fixed pitch prop that allows over 2100 static, he will never develop the pressures that your method needs.

His cylinders will stop using oil when they have filled each little chrome crack with carbon. the chrome will not wear as fast as the iron ring, so, running chrome cylinders at high pressures is actually the wrong thing to do. You are simply wearing out the ring prematurely.
 
Just a little update have about 8 hours on the engine now and i think things are starting to settle in. 3 out of the 6 cylinders the plugs are no longer wet with oil (not sure that is a sure sign but i assume it is not burning as much oil?) and CHT has started to decrease. Oil consumption is still up there a ways, any where from .5 to 1 quart an hour, still seeing quite a bit out of the breather seems like to. Hope that will start to decrease a little over the next little while! I've been trying to keep about 8.5 to nine quarts in it max and not letting it get below about 6.5.

Also had a question on warming up the engine. I have been told to not exceed 1400 RPMs until oil temp is above 100 degrees, then increase to 2000 rpms until 150 degrees then after that go full throttle. That takes a little while for it to warm up. WHat are your guys thoughts on that?
 
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