Do I need IO550G or IO550N cylinders, what kind (top)

[THill182]

I have a quick question: I decided to just go ahead and do a top overhaul on my 2000 M20R, which was converted to 310HP and 3-bladed via the standard STC. My question is: Do I buy IO550G cylinders, or IO550N cylinders, and does it matter? It seems there is ambiguous info on this out here? When the engine was converted, I did NOT get new cylinders, so that was an IO550G.

Further, is the Nickel Cylinder add-on price worth it? It seems at current prices they run about 300$ extra.

Please let me know if someone has the definitive answer on this. I want to order the cylinders ASAP as they might be back-ordered (new Continental), and prices are bound to go up again!!!

Thanks!

[aaronk25]

I've heard from mechanics that the plated cylinders can flake off or at least have in the past.

Unless it's to late research mike Busch "top overhaul" it's is almost always doesn't make the plane safer or preform better.

Sorry for the cirrus link but it's relevant read:
https://www.cirruspilots.org/cfs-file.ashx/__key/telligent-evolution-components-attachments/13-257-00-00-00-56-36-27/TT-2010_2D00_05.pdf


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[Guest]

The engine is still a IO550G, the STC just returned it to its normal rated power.  If it were a IO550N the data plate would reflect that.

Nickel carbide bores hold up better than plain TCM steel.

Clarence

[THill182]

Thanks for the quick feedback; that is what I thought, but I wanted to confirm (need the IO550G cylinders). I'll probably go with standard steel cylinders, since that is what I had and they worked quite well for almost 1300 hours I think (need to verify for sure). I have another thread where I discuss my oil usage woes. Long story short, the engine has a lot of blow-by, and goes through a quart every 3 hours -- maybe less. Instead of doctoring around one cylinder at a time, I figure I get a Top. For various reasons that are a long story, the bottom was overhauled after the last top and with cylinders at a few hundred hours (the case cracked at the propeller?!). So my plan is to fly this plane (which is a great plane) for another maybe 1000 hours (or more), and then get a new motor.

I know that there are probably cheaper ways to do this, but my engine has been very dependable for the past (over..) 10 years -- I hope to get another maybe 7 or 8 years out it without major engine work.

[bonal]

Possible will get some dispute on this but if you have a single cylinder with blow by it should be easy to identify by using a compression tester on each cylinder and listening for blow by sound from the oil filler tube and might be as simple as a hone and some new rings.

[carusoam]

I went factory reman, with the N cylinders and prop Gov set to 2700rpm...

The N cyls weigh a few pounds less and their cooling fin design is different...  I think you may need some baffle parts to go with them..(?)

If I was going all new I would be thinking....   310hp, IO550(N) with a composite TopProp

All the power, but with lower weight on the nose.

Still would want some feedback on the composite TP and IO550 before committing....

Best regards,

-a-

[StevenL757]

15 hours ago, THill182 said:

I have a quick question: I decided to just go ahead and do a top overhaul on my 2000 M20R, which was converted to 310HP and 3-bladed via the standard STC. My question is: Do I buy IO550G cylinders, or IO550N cylinders, and does it matter? It seems there is ambiguous info on this out here? When the engine was converted, I did NOT get new cylinders, so that was an IO550G.

Further, is the Nickel Cylinder add-on price worth it? It seems at current prices they run about 300$ extra.

Please let me know if someone has the definitive answer on this. I want to order the cylinders ASAP as they might be back-ordered (new Continental), and prices are bound to go up again!!!

T - the short answer is yes...although you can order the N cylinders for your G-series engine, there are a few things you need to consider.  First, read CMI Bulletin M75-6R1 (http://www.tcmlink.com/pdf2/M75-6R1.pdf) which discusses this at a high-level.  Whomever does your work will need to be very familiar (and have available) BOTH parts catalogues for the IO-550G and IO-550N engines.  Aside from the physical difference (straight fins vs. tapered on the "N"), there is more involved than simply replacing one model of cylinder with another, but the talented CMI folks can address these items.

I spoke with them this morning about an unrelated issue, and posed this question to a couple of their shop folks as well as the parts guru, Hailey Pannone.  Reach out to her directly at 251-436-8611.  She is gathering some details on this request, and can also assist you with pricing and ordering direct when you're ready.  She replaced John Bodenmann who retired about a year ago.  John took care of my IO-550N8B order, and I've been ecstatically happy I went directly thru CMI ever since.  Ping if you need anything else on this, and happy hunting!

Regards, Steve

[THill182]

4 hours ago, StevenL757 said:

T - the short answer is yes........Regards, Steve

Thanks Steve; really helpful. Based on the other replies posted here, my mechanic has ordered new steel cylinders for the G engine. But I REALLY appreciate the contact info if/as we run into any issues. This is my second time around (for a TOP), and the last one went quite well. I wish the cylinders would have lasted longer (than 1200 hours; and I may have made them last longer by just fixing one or two of the 6 cylinders), but because of the way my engine-life went (I had a cracked case that necessitated a bottom overhaul after my top overhaul -- long story), if this all works out I have may 6-10 years of unencumbered motoring and then just buy a new motor. Anyway, that is the plan....

[carusoam]

TH,

Are you using up cylinders for maximum speeds?  50° ROP will probably do it...

Or are you flying LOP and still having bad luck?

Do you have any JPI data that you may want to share?

Do you climb using the blue box / target EGT method?

Are you familiar with the #5 'pixie hole'?

what CHTs do you usually encounter?  Running LOP, you may see 320°F in the summer and 280°F in the winter...  These come from old memories of flying at 12,500'

These were things I was interested in to help avoid having to top the IO550G...

Thinking out loud,

-a-

 

[aaronk25]

A qt every 3 hours? How long has it been burning oil at that rate? One cylinder with a stuck ring can burn that amount.

When I crossed the Gulf of Mexico my 4 cylinder was burning 1qt every 2 hours but we knew the problem was a stuck ring on #4 cylinder. It wasn't going to quit at least not due to a stuck ring and there was no way I was was going to cross water with "new parts" so we flew it that way.

Does your mechanic do borescope camera inspections? If so what cylinder(s) is the offender?


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[Guest]

We change far more N series cylinders due to cracked cylinder heads than we ever have any other cylinder series.  I wouldn't buy them.

Clarence

[ArtVandelay]

12 hours ago, aaronk25 said:

A qt every 3 hours? How long has it been burning oil at that rate? One cylinder with a stuck ring can burn that amount.

When I crossed the Gulf of Mexico my 4 cylinder was burning 1qt every 2 hours but we knew the problem was a stuck ring on #4 cylinder. It wasn't going to quit at least not due to a stuck ring and there was no way I was was going to cross water with "new parts" so we flew it that way.

Does your mechanic do borescope camera inspections? If so what cylinder(s) is the offender?


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How did you know which cylinder?  Compression test or borescope?

[aaronk25]

How did you know which cylinder?  Compression test or borescope?

Borescope, could see the oil pooling in cylinder more than others. Also plugs where drastically oiler than others but to be honest the main smoking gun was the oil residue all over the intake and exhaust stack with no other apparent leak.




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[THill182]

16 hours ago, carusoam said:

TH,

Are you using up cylinders for maximum speeds?  50° ROP will probably do it...

Or are you flying LOP and still having bad luck?

Do you have any JPI data that you may want to share?

Do you climb using the blue box / target EGT method?

Are you familiar with the #5 'pixie hole'?

what CHTs do you usually encounter?  Running LOP, you may see 320°F in the summer and 280°F in the winter...  These come from old memories of flying at 12,500'

These were things I was interested in to help avoid having to top the IO550G...

Thinking out loud,

-a-

 

carusoam: I am disappointed that I have those problems after only 1100 to 1200 hours.

I am flying LOP in cruise all the time. One mistake I may have made is that I tried to "save-the-engine", so usually flew 60% power, and never more than 65% and 2550-2600RPM; I since learned and believe that there is no value in this, and it's best to run 75% when available).

I have the "pixie hole", and my CHT's never go past 380F (in fact #5 is not the hottest any more); in cruise all cylinders are well below 340F actually at any altitude.

On climb-out I fly ROP, always 2 or 3 "clicks" to the left of the "blue-zone" on the Moritz gages; so I am running very rich to altitude, keeping CHT's below 380. Usually, I pull back to 24 Hg MP and 2,600 RPM on initial climb out after 1 minute or so (after reaching 1200ft AG).

For about 300 hours a few years back, my fuel-flow wasn't set up right (was set up by someone to 270 hp, not 310 hp); that caused a bit higher CHT's for a few months, before I had that fixed.

I have one other theory: There was a lot of "movement" at my work, so that I ended up for 6 to 8 months flying less regularly, sometimes letting the plane sit for 3 weeks even 4 weeks, and often flying for practice mostly, so short 1-2 hour trips with lots of touch and goes, approaches, and so on. After that it all started with the oil usage. Before that time, I flew a lot for business, and my pattern was to fly mostly x-country on 3-4 hour trips.

One final thought: Look through ASO or Controller, or Trade-a-Plane, and look at the TSMOH or since TOP for Ovations: They almost all have had work done at 1200 hours or less. Compare that with my (favorite previous) plane, the 182 Skylane RG with the Lycoming O540: Many/most of them have 2000+ hours on the engine. So overall, I feel that I was not particularly unlucky, or unusually inept at the controls (my 182 never had any engine problems in 1500 hours).

My plan now is to use Camguard regularly, continue to use 100 weight oil (as I always had, in all weathers), pre-heat religiously (as I always had), but not "baby-the-engine" any more, but fly it at/below 75% and LOP. I hope to report on the results of that experiment in 8  years from now when I should be approaching 1000 hours on my new cylinders without any problems

[PMcClure]

1 hour ago, THill182 said:

carusoam: I am disappointed that I have those problems after only 1100 to 1200 hours.

I am flying LOP in cruise all the time. One mistake I may have made is that I tried to "save-the-engine", so usually flew 60% power, and never more than 65% and 2550-2600RPM; I since learned and believe that there is no value in this, and it's best to run 75% when available).

I have the "pixie hole", and my CHT's never go past 380F (in fact #5 is not the hottest any more); in cruise all cylinders are well below 340F actually at any altitude.

On climb-out I fly ROP, always 2 or 3 "clicks" to the left of the "blue-zone" on the Moritz gages; so I am running very rich to altitude, keeping CHT's below 380. Usually, I pull back to 24 Hg MP and 2,600 RPM on initial climb out after 1 minute or so (after reaching 1200ft AG).

For about 300 hours a few years back, my fuel-flow wasn't set up right (was set up by someone to 270 hp, not 310 hp); that caused a bit higher CHT's for a few months, before I had that fixed.

I have one other theory: There was a lot of "movement" at my work, so that I ended up for 6 to 8 months flying less regularly, sometimes letting the plane sit for 3 weeks even 4 weeks, and often flying for practice mostly, so short 1-2 hour trips with lots of touch and goes, approaches, and so on. After that it all started with the oil usage. Before that time, I flew a lot for business, and my pattern was to fly mostly x-country on 3-4 hour trips.

One final thought: Look through ASO or Controller, or Trade-a-Plane, and look at the TSMOH or since TOP for Ovations: They almost all have had work done at 1200 hours or less. Compare that with my (favorite previous) plane, the 182 Skylane RG with the Lycoming O540: Many/most of them have 2000+ hours on the engine. So overall, I feel that I was not particularly unlucky, or unusually inept at the controls (my 182 never had any engine problems in 1500 hours).

My plan now is to use Camguard regularly, continue to use 100 weight oil (as I always had, in all weathers), pre-heat religiously (as I always had), but not "baby-the-engine" any more, but fly it at/below 75% and LOP. I hope to report on the results of that experiment in 8  years from now when I should be approaching 1000 hours on my new cylinders without any problems

Your experience pretty much mirrors mine (2002 Ovation 2 280HP). Except for a lucky few of us, most 550's I see need a top mid term, unless it is a turbo. Then plan on one at 500 hours.  I made it to 1350 hours and was burning 1 quarter per 3 hours. Occasional plug fouling on 2 cylinders. Good bore scopes. Low compressions across the board and a defending trend on all of them. I decided to top the engine. Oil consumption is back to 1 quart every 8-9 hours and TAS up 5 knots. 

[gsengle]

I'm at 1950 hours, only 2 cyl replaced since new... I'm just most recent custodian, but always cruise LOP for what it's worth....


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[aaronk25]

carusoam: I am disappointed that I have those problems after only 1100 to 1200 hours.
I am flying LOP in cruise all the time. One mistake I may have made is that I tried to "save-the-engine", so usually flew 60% power, and never more than 65% and 2550-2600RPM; I since learned and believe that there is no value in this, and it's best to run 75% when available).
I have the "pixie hole", and my CHT's never go past 380F (in fact #5 is not the hottest any more); in cruise all cylinders are well below 340F actually at any altitude.
On climb-out I fly ROP, always 2 or 3 "clicks" to the left of the "blue-zone" on the Moritz gages; so I am running very rich to altitude, keeping CHT's below 380. Usually, I pull back to 24 Hg MP and 2,600 RPM on initial climb out after 1 minute or so (after reaching 1200ft AG).
For about 300 hours a few years back, my fuel-flow wasn't set up right (was set up by someone to 270 hp, not 310 hp); that caused a bit higher CHT's for a few months, before I had that fixed.
I have one other theory: There was a lot of "movement" at my work, so that I ended up for 6 to 8 months flying less regularly, sometimes letting the plane sit for 3 weeks even 4 weeks, and often flying for practice mostly, so short 1-2 hour trips with lots of touch and goes, approaches, and so on. After that it all started with the oil usage. Before that time, I flew a lot for business, and my pattern was to fly mostly x-country on 3-4 hour trips.
One final thought: Look through ASO or Controller, or Trade-a-Plane, and look at the TSMOH or since TOP for Ovations: They almost all have had work done at 1200 hours or less. Compare that with my (favorite previous) plane, the 182 Skylane RG with the Lycoming O540: Many/most of them have 2000+ hours on the engine. So overall, I feel that I was not particularly unlucky, or unusually inept at the controls (my 182 never had any engine problems in 1500 hours).
My plan now is to use Camguard regularly, continue to use 100 weight oil (as I always had, in all weathers), pre-heat religiously (as I always had), but not "baby-the-engine" any more, but fly it at/below 75% and LOP. I hope to report on the results of that experiment in 8  years from now when I should be approaching 1000 hours on my new cylinders without any problems

Run 20w-50 Phillips in the winter. The reason why isn't limited to just cold starts. It also a greater chance of congealing a oil cooler in external cold temps. Don't ask me how I know.


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