Io360 a1a cylinder blow by. Replace?

[Teddyhherrera]

14 minutes ago, Shadrach said:

An IO360 with the fuel system set to factory specs will not typically have issues with lead deposits. Perhaps at very high DAs his might be an issue. Best course of action is probably to lean for the highest EGT as plug fouling is more a function of plug temperature than mixture. 

I have been in and around Lycoming engined Mooneys since birth. My father has owned a C, an E and an F model. He never leaned any of those airplanes for taxi. Lead fouled plugs were never an issue for him. DA’s at our 701’ drome vary from -3000 to nearly 4000’ depending on season.

Ah yes. DA here is rarely less than 5-6000. Field elevation is 3950. 

[Fly Boomer]

11 hours ago, Teddyhherrera said:

There's not a single person, I've spoken to that says this has worked for them. I think the score right now is 0- 12 between both online and at the airfield. I'm willing to give it a shot though

If you decide to try it, get someone who has done it a few times and is willing to follow instructions.

[M20F]

13 hours ago, Teddyhherrera said:

That's what my a&p said. Am I describing symptoms of another issue?

Everything I have seen you describe is a normal running engine.  If the compression is good and the oil consumption both reasonable and stable, not sure exactly what the problem is. 

[Shadrach]

12 hours ago, 1967 427 said:

Higher than normal cylinder temps combined with the fact that you said you don’t get an RPM drop during mag run up check, says to me that you may have more than 20 degrees of advance on the timing.  Check timing this may solve some issues.

My engine is timed to 25° and still get a normal mag drop and I never see CHTs near 400° on climb out.  

[Shadrach]

13 minutes ago, M20F said:

Everything I have seen you describe is a normal running engine.  If the compression is good and the oil consumption both reasonable and stable, not sure exactly what the problem is. 

Oily plug…that is all.

[Shadrach]

I’ve done some more research on nickel cylinders and I’m getting mixed information. Can anyone confirm if they have/don’t have a crosshatch hone.  Some sources say yes and some sources say no hone but fine carbide grit mixed in plating to facilitate oil wetting.  I had always heard the latter but some sources say a shallow 15° crosshatch is used. 

[Will.iam]

58 minutes ago, Teddyhherrera said:

Ah yes. DA here is rarely less than 5-6000. Field elevation is 3950. 

Holy cats 4000ft that would make your mixture super rich with the mixture knob all the way in as it has to be able to give you enough fuel for Take off when you are at sea level. Either find out what your EGT’s are supposed to be at for take-off or fly to a sea level airport and do a take-off there and note what your egt’s are showing on take-off then when you go back to your airport just lean the mixture to bring your egt’s to the same value you saw at sea-level that will get you to rated power. With so much extra fuel you are losing power by being way too rich. 

[Immelman]

I put a fine wire spark plug in the bottom of my cylinder that was oil fouling a bit (and easily cleared with 2-5 seconds of runup at higher power than normal). 600+ hrs later..... AOK!

[Shadrach]

2 hours ago, Will.iam said:

Holy cats 4000ft that would make your mixture super rich with the mixture knob all the way in as it has to be able to give you enough fuel for Take off when you are at sea level. Either find out what your EGT’s are supposed to be at for take-off or fly to a sea level airport and do a take-off there and note what your egt’s are showing on take-off then when you go back to your airport just lean the mixture to bring your egt’s to the same value you saw at sea-level that will get you to rated power. With so much extra fuel you are losing power by being way too rich. 

I’m not sure that you quite understand how the Bendix RSA FI system works. His engine is certainly running richer than it would be at full rich sea level…how much richer, is hard to say.  Raw EGT numbers would shed some light. It’s likely not running “super rich” given that he has CHTs pushing 425°  in the climb.

[Teddyhherrera]

2 hours ago, Will.iam said:

Holy cats 4000ft that would make your mixture super rich with the mixture knob all the way in as it has to be able to give you enough fuel for Take off when you are at sea level. Either find out what your EGT’s are supposed to be at for take-off or fly to a sea level airport and do a take-off there and note what your egt’s are showing on take-off then when you go back to your airport just lean the mixture to bring your egt’s to the same value you saw at sea-level that will get you to rated power. With so much extra fuel you are losing power by being way too rich. 

Yes. I've always leaned just nowhere near enough. I figured just bringing it further down a bit was enough. It was not. 

[Teddyhherrera]

2 hours ago, Immelman said:

I put a fine wire spark plug in the bottom of my cylinder that was oil fouling a bit (and easily cleared with 2-5 seconds of runup at higher power than normal). 600+ hrs later..... AOK!

This is the plan if I have any problems again 

[Shadrach]

42 minutes ago, Teddyhherrera said:

Yes. I've always leaned just nowhere near enough. I figured just bringing it further down a bit was enough. It was not. 

For take off you want raw EGT values of around 1175°-1225°. The lower the DA, the more you want to er towards lower take off EGTs. 

[kortopates]

17 hours ago, Teddyhherrera said:

There's not a single person, I've spoken to that says this has worked for them. I think the score right now is 0- 12 between both online and at the airfield. I'm willing to give it a shot though

 

17 hours ago, PT20J said:

It probably depends on what the problem is. I've talked to people that freed up a stuck compression ring and raised the compression with the technique. I don't personally know of anyone that has used it for high oil consumption, but @kortopateswould be the expert on this. At least is is simple and noninvasive.

It doesn't always work but it has saved a great many cylinders for us and you have nothing to lose trying it.

Here is one of Mike's articles explaining both the ring flush and valve lapping procedures:

AOPA_2024-03_ending-the-war-on-jugs.pdf

Here is a current link to the procedure details and recipe for the ring flush solvent

savvy-oil-control-ring-solvent-flush.pdf

[M20F]

5 hours ago, Will.iam said:

Holy cats 4000ft that would make your mixture super rich with the mixture knob all the way in as it has to be able to give you enough fuel for Take off when you are at sea level. 

Let’s separate problems.  This has nothing to do with overhauling a cylinder or oily plugs which is where we started.  
 
I go in and out of KTOR for antelope hunting and if I am light I don’t even bother with the turbo.  I don’t see mixture as a problem either. 
 

I honestly don’t know what the perceived issue is here.  

[Ragsf15e]

3 hours ago, Teddyhherrera said:

Yes. I've always leaned just nowhere near enough. I figured just bringing it further down a bit was enough. It was not. 

Just to be clear, are you talking about leaning during your ground ops, takeoff, climb, cruise, all of the above?

Heres a quick primer to make sure you’re on the same page with what most of us are saying…

Ground ops ( @Shadrach  is going to disagree with this but it certainly won’t hurt anything), lean it way back.  Like to the point where it stumbles and just barely push it in to run smooth.  This hurst nothing as you are at real low power.

Run up, you will need to be more rich but not full rich, especially at your DA.  You won’t hurt anything doing a normal runup leaned out somewhat and you’ll likely get a better idea of the health of your ignition.

Takeoff, most of us use a target egt number (like shadrach mentioned ~1200 egt) to set the mixture on takeoff.  At your DA, you certainly need to lean some.  This target egt is found by doing a full rich sea level takeoff and noting your egts but around 1200 is close.  You could also do a full power runup to find a good mixture.

Climb, climb at a faster speed than Vy for cooling.  I use ~110-115mph indicated (mine is mph not knots), and lean every few thousand feet as you climb to maintain that target egt.  If your cylinders are going above 400, make it a little richer (and speed up).  If you’re too lean during takeoff or climb you will quickly see hot chts, so be careful here.

Cruise, lean to peak egt and then choose either rich by about 100 degrees (from the first cylinder to peak) or just slightly lean of peak (from the last one to peak).  If you’re lean of peak, leaner still gets cooler chts while richer is warmer.  It’s the opposite if you’re rich of peak.

Ask questions about what doesn’t make sense to you.  It’s not good just to go out and run real lean without knowing when/why you’re doing it and what you’re supposed to get from it.

Edited October 25, 2024 by Ragsf15e

[Jim Peace]

Wow 4 pages in this thread. Don’t have time to read it all but to the OP maybe a bit of marvel mystery oil. That stopped an oil issue I was having. It was just a stuck ring in the spot that caused more oil usage. Problem was solved in about 10 hours. Used it in the oil and the gas. 

[Z W]

My M20C would foul a plug (with lead) if you did not lean for taxi.  I do not remember at this point how the fuel system was setup, may not have ever been verified to be to factory specs.  But I can verify that at least some of them do it out in the wild.

My current M20K will also do it, though not as quickly.  I know its fuel system is set on the very rich side of factory specs for extra cooling in the climb, which works well.  But the tradeoff is you have to lean for taxi.

I just had this thought because the OP seems new to this engine and was reporting fouled plugs while leaving the mixture too rich, and everything else seemed normal.  Leaning for taxi would be an easy thing to try to help identify the real problem.

[EricJ]

2 hours ago, Z W said:

My M20C would foul a plug (with lead) if you did not lean for taxi.  I do not remember at this point how the fuel system was setup, may not have ever been verified to be to factory specs.  But I can verify that at least some of them do it out in the wild.

My M20J would do this, too, when I first got it.   Maxwells suggested leaning on the ground and keeping it at or above 1000 rpm.   Between that and putting fine wire plugs in the bottom it's never done it since.   Idling too long full rich can definitely do it.

[kortopates]

…
My current M20K will also do it, though not as quickly.  I know its fuel system is set on the very rich side of factory specs for extra cooling in the climb, which works well.  But the tradeoff is you have to lean for taxi.
….

Your idle mixture is entirely independent from your max fuel flow set up. However after adjusting one end the other end needs to be re-checked and adjusted if need be. If someone merely raised your max fuel flow set and didn’t check your idle setting it could leave you overly rich at idle. But that should be fixed if your idle mixture is out of adjustment. And it’s easy for the pilot to check that too.

It is normal though for any engine to benefit from leaning after startup and more so the more above sea level.


Sent from my iPhone using Tapatalk

[Shadrach]

On 10/25/2024 at 4:57 PM, Ragsf15e said:

Just to be clear, are you talking about leaning during your ground ops, takeoff, climb, cruise, all of the above?

Heres a quick primer to make sure you’re on the same page with what most of us are saying…

Ground ops ( @Shadrach  is going to disagree with this but it certainly won’t hurt anything), lean it way back.  Like to the point where it stumbles and just barely push it in to run smooth.  This hurst nothing as you are at real low power.

Run up, you will need to be more rich but not full rich, especially at your DA.  You won’t hurt anything doing a normal runup leaned out somewhat and you’ll likely get a better idea of the health of your ignition.

Takeoff, most of us use a target egt number (like shadrach mentioned ~1200 egt) to set the mixture on takeoff.  At your DA, you certainly need to lean some.  This target egt is found by doing a full rich sea level takeoff and noting your egts but around 1200 is close.  You could also do a full power runup to find a good mixture.

Climb, climb at a faster speed than Vy for cooling.  I use ~110-115mph indicated (mine is mph not knots), and lean every few thousand feet as you climb to maintain that target egt.  If your cylinders are going above 400, make it a little richer (and speed up).  If you’re too lean during takeoff or climb you will quickly see hot chts, so be careful here.

Cruise, lean to peak egt and then choose either rich by about 100 degrees (from the first cylinder to peak) or just slightly lean of peak (from the last one to peak).  If you’re lean of peak, leaner still gets cooler chts while richer is warmer.  It’s the opposite if you’re rich of peak.

Ask questions about what doesn’t make sense to you.  It’s not good just to go out and run real lean without knowing when/why you’re doing it and what you’re supposed to get from it.

I don’t disagree. I typically lean for taxi. I just know a living, breathing, example of a pilot (my father) with 3k+ Mooney hours, that never leaned any of his three Mooneys for taxi.  Whether injected or carbureted, his engines suffered no ill effects from full rich ground operations. That does not mean that I’m advocating against leaning for taxi. However,  I do think it’s usually a red herring to attribute maintenance issues to full rich ground ops, specifically with regard to injected Lycomings.  Ground leaning can help mitigate a poorly adjusted idle/air mixture, but it would be best to set the idle air mixture to the proper spec. 
 

 

 

[Shadrach]

On 10/23/2024 at 11:25 AM, Teddyhherrera said:

I maybe see 425 on my hottest cylinder on initial climb out, oil runs cool, BUT my MX says it will only get worse

425° is high for a stock F model.  I don’t think my engine is ever seen 425° CHT in its lifetime.  Indeed, in 25 years of operation, I think I can count the number of times I’ve had a CHT over 400° on one hand.   Is your cowl I’d love to stock?

On 10/23/2024 at 11:25 AM, Teddyhherrera said:

On 10/24/2024 at 10:50 PM, Teddyhherrera said:

I don't have higher than normal cylinder temp and I do get a mag drop. It was out of tolerance for the right mag. I would get 2-300 on the right and have to really lean it out.

What do you mean “have to really lean it out”? Mag drop is a function of timing. Improper timing on either or both mags will cause a mag drop. What does that have to do with mixture?

[A64Pilot]

On 10/24/2024 at 11:18 PM, MikeOH said:

Just to say it again, my oil consumption got WORSE after I tried the ring flush.  One more data point to keep in mind.

I would expect it to get worse if it cleaned out gunk from the oil ring

[A64Pilot]

With no disrespect, but I think the original poster needs to understand leaning a little better than it seems he does before he just starts leaning it out a lot more. I could of course be wrong, it just seems he may not have a good understanding

You can hurt an engine at high power with the mixture knob, hurt badly if improperly done.

I would advise as a min to learn the average peak, I know it changes from day to day but it’s usually pretty close, once you know what it is be sure not not lean less than 100F ROP, 150 isn’t a bad number actually during high power ops like T/O and climb, then watch Cyl head temp while climbing at least 100 kts indicated, if it climbs above 400 enrichen the mixture to get it down if it won’t come down more than likely you have a baffling problem that needs fixing. Don’t climb at Vx or Vy especially if it’s getting hot, our cooling comes from airflow of course and higher air speeds increase cooling, obviously.

A plug will not foul at high power even if very rich. It can foul if low power and real rich though, a plug runs hotter at high power of course

Once you’re at cruise and below 75% power, now is the time to lean the snot out of it, personally I lean it to 50 or so lower than peak, so leaner than peak, but ROP is fine too, even peak if not high power is fine.

Usually to hurt a motor you need to be close to peak, have hot as in more than 400F cylinder heads and high power, remove any of those three and it’s unlikely you will hurt one.

Without knowing anything about your airplane, you or your engine I can’t say for sure but your hot heads sound like to me that your climbing slow and or possibly leaner than optimum for climb power, or both, or arguably not lean enough although that’s graduate level mixture control in my opinion. If your not real sure most conservative response is be rich, rich enough that your sure your real rich when at T/O and climb power.

Edited October 29, 2024 by A64Pilot

[LBM]

On 10/29/2024 at 9:45 AM, Shadrach said:

What do you mean “have to really lean it out”? Mag drop is a function of timing. Improper timing on either or both mags will cause a mag drop. What does that have to do with mixture?

What I think OP said was that he got an excessive drop on right mag, because it was contaminated, or mildly fouled, because of overly rich mixture during ground operations, and that he had to aggressively lean during runup to burn it clean.  You’re assuming timing is the only reason for anomalous mag drop, and it’s not.  It’s happened to me from overly long overly rich ground runs, and a very lean runup cured it.  What does that have to do with timing?

[skykrawler]

Pooled oil seems quite common with Lycoming's. My theory is it accumulates on the taxi back to the hanger.  I had a high time engine that did it - but when I landed from a 2 hour cruise and stopped the engine after a brief taxi, the lower plug was clean and a nice color.

My advice for getting a plug miss-fire from pooled oil during run up is to change the order of your checklist.

Move the mag check to the latest item.  Set the idle to 1200 rpm while performing the checklist.  And, do the propeller cycle check before the mag check.   Lastly, use the Lycoming documented procedure to perform the magneto check at less than full rich.

Its worth understanding that detecting plug miss firing is only part of what the mag check is about.  The normal 'drop' is a function of only running on one magneto.  The spread between the two can be a shift in the timing of the magneto or in the worst case some other real problem with the magneto (leaking coil- whatever).

I operate at an airport where on rare occasion there is the dreaded two mile taxi.  A good reason to lean as much as possible.