Continental Engine Woes

[WindOnHisNose]

I value the knowledge of you all, and would welcome comments regarding a problem I am facing.

*I have just taken my CT210 in for annual and have to make a decision regarding the engine. *I fly about 250 hours/year, flying once per week, generally. *I put a factory reman TSIO-520L into the aircraft in July of 2005, found the compressions low in 3/6 cylinders in 2007, having a top overhaul performed with factory new cylinders (under warranty) at 450 hours TTSN, then had low compression in #4 in 2009, sending that in for repair, then #1 in 2010, sending that in for repair. *The general pattern is at about 400-500 hours one or more cylinders lose compression.

The repairs to #1 an #4 were done at a local shop that has an excellent reputation and I know the owner, Darell Bolduc, quite well...he is the most respected engine man in the upper midwest. *I asked him if I am doing something wrong, and he said he didn't think so. *He told me that this scenario would have been unusual 15 years ago, but that they see this exact thing on most Continental engines, particularly turbocharged ones, since then. *He feels Continental uses an inferior metal alloy now, and that this is the likely problem. *I might also add that I have GAMI injectors installed and have run 50 degrees rich of peak, and 50 degrees lean of peak, but both have resulted in cylinders that lose compression.

I just found out that my engine, at 1100 hours TTSN, has cylinders with compressions of:
#1 63/80
#2 18/80
#3 62/80
#4 60/80
#5 5/80
#6 2/80

Obviously, I need do a top overhaul, vs replacing the engine. *Given the history, I am going to likely do a top overhaul.

The first question I have is where should I buy the cylinders. *Options, in order of recommendation by Darrell Bolduc's shop, include #1, Millenium; #2 Factory new; #3 ???
What would you suggest?

The second question is related to how I run the engine. *I fly at least once per week, the aircraft is hangared, generally, but when I fly to Minot, Bismarck, Fargo, etc, I plug it in to let the Tanis heater do it's thing, cover the engine. *I always let the engine get up to 100 degrees F before initiating flight. *I have run 50 degrees rich of peak, generally, but have been told by some that this is a bad place to run the engine. *Darrell feels that running lean of peak is the way to go and I have done so with the GAMI injectors in place. *Do you have any suggestions?

I appreciate any feedback. *The CT210 is a critical part of my medical practice, using it to deliver care to people living across the upper midwest, and I baby this aircraft. *Thanks for any input.

Randy

 

[P.o.P]

Are the Low Compression readings caused by rings, valves or ?

Making metal ?

I got involved in something like this MANY tears ago.

Changing oil & changing cylinders were the same.

In that case incorrect Shut-down Procedures took the blame.

A rapid shut-down resulted in coked turbo seals was the "rumor".

Still don't understand that but you may ask the big guys.

 

[Darrel Starr]

Randy, I don't think there is a viable #3 option beyond Millenium and Continental. I haven't heard much good about ECI -- those are the folks that made the push rod tube springs that failed on my engine.

 

[Dave Calkins]

Go fly the a/c with Darrel and have him critique your power setting procedure to determine what is going wrong.

I am not TSIO-520L savvy. I would think power setting, and how you arrive at the settings are a likely culprit. Having an expert sitting next to you and observing is better than describing your ops. to him.

Sorry for you on this issue. It seems like spending money on fuel is better than spending it on cylinders.....which is what I tell guys who operate at low-altitude here......some of them even listen....eventually...

Do you have the Knisely exhaust crossover delete and heater modification? I guarantee that it saved one operator I know alot in exhaust system repairs every 50 hours at the AD inspection.

 

[Bill Rusk]

Randy

Funny you should bring this up. I just got off of the phone with Terry (flew the Cub on floats to E Tenn with us). His cont powered Cub and Champ have basically both needed tops between 200 and 250 hrs. When I had my C-170, I had exhaust guide problems every 200 to 250 hrs. Just seems to be a problem with continental engines. Ask Pokette about her 0-200 experience. I know these are smaller versions than what you are running, but in all cases the engines were being well cared for and flown 250 hrs plus a year. Great bottom ends, that with regular use will go 3000 plus, with no problems but the exhaust guides, seats, and valves all seem to be the weak point, based on my limited sample size. I don't think it is operator error. I don't think Pokette's was operator either.
Just my opinion.

Bill

 

[180Marty]

The engine shop down in Omaha showed me a factory 520 cylinder that had a heck of a ridge at the top of the stroke. I think it had 7 or 800 hrs since new and they felt it was soft metal. They recommend ECI nickel.

 

[ag-pilot]

Randy, Don't know on the 210 but on the Cessna Ag planes the turbo engines are just not worth the trouble unless you really need the extra hp to get above weather. We put a I0550 in the A36 Bonanaza and have had no issues in 400 or so hours since factory new. The 520 we took out had 2100 SFREMAN with no issues and was running fine. I run the big continentals hard 2500 RPM and all the MP I can get. I also warm them up and cool them down and run rich of peak a bit.
Dave

 

[mike mcs repair]

Are the Low Compression readings caused by rings, valves or ?
...

that was my first thought/question...???

 

[bob turner]

My first thought is how often do you do compression tests? I personally do a test each day before the first flight. My AEIO 360 had a very weak cylinder last month - I thought "here we go" but rather than pull the cylinder I waited until after that day's flight and checked it again. Perfect!

The Helio went in to the local repair shop for a differential comp test, and two cylinders were in the thirties. So we flew it around the pattern and I took the potential customer and placed the gauge in his hand. Those two low cylinders were among the best, at high 70s. I was not even looking at the gauge as I moved the prop to tdc. Lowest cylinder was low 70s.

Most will pull a cylinder based on a single trial, and will often find that the rings are all temporarily aligned. Full employment act? As to the thought that the engine will fall apart if operated with a low cylinder, remember that most get a compression check only once a year.

Opinion.

 

[WindOnHisNose]

The valves were the problem when the cylinders were removed, each time.

I take time warming the engine up (to 100 F), take time cooling it down, get the cowl flaps open as soon as I am on the ground. If I am on the ground the cowl flaps are open.

I have had a couple of people that I consider good engine people fly with me, and they both came away without criticism of the technique I used. I watch the CHT's closely, never let them get very hot.

I agree with the feeling that gas is a lot cheaper than overhauls. The data on lean of peak strongly suggest that LOP ops are easy on the engine...provided GAMI's are installed.

I appreciate the input, I'm listening.

Randy

 

[okmike]

Randy

This is the link to the TCM Service Bulletin we talked about

http://www.genuinecontinental.aero/servicebulletins.html

After it opens click on: SB03-3

 

[cruiser]

Randy, Let me say upfront I don't know beans about a big Continental but since I just purchased an EI UBG-16 for my Super Cub I have been spending time recently viewing the webinars here, http://www.savvymx.com/index.php/resources/webinar and here http://www.eaavideo.org/video.aspx?v=994986557001 on EGT/CHT, leaning and engine monitors. The author claims he has run his turbo something Cessna 310 900 hours past TBO by running lean of peak consistently and also states 50 degrees ROP is THE most stressful condition for your cylinders and provides some data to back that up. The webinars are painfully slow viewing but it's what I can offer. Good luck, Jim

 

[mvivion]

Randy,

What power settings are you running? What are your metered vs unmetered fuel flows? This was one of the initial problems we had with IO 550 installations on 206s. Fuel flows were specified way too low by the STC and we were stepping cylinders and frying valves. Once we got the fuel flows higher than the factory initially recommended, the engines really sung and ran much cooler. These were IO's though. I assume that TSIO airplanes would have the same issue, potentially. I found it difficult to get some mechanics to set up the fuel flows as high as we wanted them on those engines.

I don't know who Loren Lemen works for now, but he used to be Continental's head tech rep, and he understands Continental engines like nobody else. He's now working for one of the big engine rebuilders. I'd call Teledyne Continental and ask for Loren Lemen, and see if you can get a current contact number for him. I'd bet he's going to be your best source of info on big Continentals.

I know less than nothing about TSIO Continentals, but like Ag Pilot, in my past life we found that the IO 550's were a waaaaay better engine as to reliability, after the initial learning process, on the C 206s. Lots of power.

Then again, if you need the altitude performance, the TSIO engines may be your only option. All the guys I knew who ran the TSIOs on 206s got rid of them at first overhaul, but that was always low level, floats, and short hops, which is NOT what turbo chargers are for.

Still, your experience doesn't sound good, or "normal". I'd sure try to get in touch with Loren. He is a wealth of knowledge. You've probably met him or seen him...he's at the Montana conference every year.

MTV

 

[nanook]

Give us more info to work with....TO MP, fuel flow/press at TO...How are you leaning? (reference)Have you checked the accuracy of your TIT/EGT?....Did you set up your metered/unmetered fuel pressures with an accurate gauge....Is your engine timed correctly.....

 

[Steve Pierce]

Years ago I maintained 5 Cessna 210 of which 3 were turbo. First thing I would check is fuel flow. Look at the pilot handbook and see if the fuel flow on take-off is as published. Have seen several TCM fuel controls set up incorrectly. I would also consider an engine monitor if you don't have one to see what is going on. My experience was uaually problems with number 2 in the T-210 from lack of proper cooling but your problem seems like a fuel flow issue. Have had very good luck with ECI cylinders especially Nickel. Marshall Gibson at Gibson Aviation told me they are seeing first run ECI Nickel cylinders with cylinder bores measuring out to new limits. SJ has new ECI Nickel cylinders on his C180 and he hasn't had any problems yet and he is pretty hard on stuff.

 

[Scooter7779h]

Years ago I maintained 5 Cessna 210 of which 3 were turbo. First thing I would check is fuel flow. Look at the pilot handbook and see if the fuel flow on take-off is as published. Have seen several TCM fuel controls set up incorrectly. I would also consider an engine monitor if you don't have one to see what is going on. My experience was uaually problems with number 2 in the T-210 from lack of proper cooling but your problem seems like a fuel flow issue. Have had very good luck with ECI cylinders especially Nickel. Marshall Gibson at Gibson Aviation told me they are seeing first run ECI Nickel cylinders with cylinder bores measuring out to new limits. SJ has new ECI Nickel cylinders on his C180 and he hasn't had any problems yet and he is pretty hard on stuff.

I operated a Cessna T310 RAM conversion and two 320s. All RAM uses is ECI nickle cylinders. I agree with Steve, fuel flow is critical, the RAM conversions require a fuel totalizer to be installed. The Cessna fuel flow meters can be way off. RAM's operation charts had fuel flow as the key in making power settings. Dead accurate with the totalizers.

BTW, in five years, fleet of 3, putting on about 600 hrs per plane, never had a bad cylinder.

 

[nanook]

Cessna's fuel flow gauge is just a pressure gauge with flow written on it....It is very critical that the fuel pressures are where they should be in continentals instructions....

 

[mike mcs repair]

It is very critical that the fuel pressures are where they should be in continentals instructions....

or above(or at least at hi part of range).... for the top number..... like to set so ff gauge strait up on TO....

 

[Dave Calkins]

Cessna's fuel flow gauge is just a pressure gauge with flow written on it....It is very critical that the fuel pressures are where they should be in continentals instructions....

Which is why believing the Cessna gauge is foolhardy.

Checking fuel flows to the engine book is critical to longevity. These things like fuel.

 

[supercrow]

continental engine woes

For what it's worth. Certainly not a complete fix but worth considering. About a dozen years ago, I worked for a couple years in a shop where we maintained some 185's for the Maine Fish and Wildlife Service. We were replacing cyls. regularly at 300 to 500 hrs. almost always with valve problems. We started hand lapping the valves right out of the box before installing them and more that doubled the times. The seats as ground were pretty rough and it didn't take long to get a spot that would quickly worsen. Might be worth thinking about in some cases. Good luck with your engine. This cyl thing has been going on way to long and should have been corrected by now!

 

[mvivion]

Which is why believing the Cessna gauge is foolhardy.

Checking fuel flows to the engine book is critical to longevity. These things like fuel.

Exactly. We wound up with the 550s running over 29 gph at takeoff power on a calibrated fuel flow meter (and the stock pressure gauge pegged), and those engines loved that, and stopped killing cylinders.

Fuel flows are critical on Continentals, and more is better.

MTV

 

[skywagon8a]

I had a intercooled TSIO-520 in my 185 with continual similar problems until I increased my fuel flow enough to keep the cylinder head temps below 390 degrees. I also stuff an oily rag in the exhaust stack right after shutdown to keep the engine from drawing in moist air. This keeps rust from forming on the valves. I found it to be extremely important to keep the indicated airspeed as high as possible in order to maintain as much ram cooling air as possible. Heat is the enemy. In my case running 1 gallon an hour richer than recommended leaning procedures seemed to be the answer.

Randy, do you have a local mechanic who can rework your old cylinders instead of exchanging for an unknown? There must be a good high quality engine man in your neck of the woods. You have not stated what the problem is with your cylinders other than low compression. If it is just valves and guides, it might be better just to fix the problem and burn 1 more gallon of gasoline.

 

[gdrean]

Randy,

As indicated above, I think the secret is fuel flow, especially at take-off. I just put a factory reman IO-520 in my C-206, and put a fuel flow guage in at installation. From the factory the take off fuel flow was low. We set it up to the middle of the suggested range, but the temps were not to my liking. I read an article about using boost pump fuel on take off. My normal fuel flow at take off was 26.1 GPH, about middle of the range. With boost pump on it went to 28 GPH. EGT temps came down dramatically on take off, and CHT reduced some what. I am going to see if we can set up the normal Take off fuel flow to 27 or higher.

Gary

 

[Bonanza32GF]

Randy,
I suggest that you swap your turbo IO-520 for the Atlantic Aero Conversion using the Continental IO-550(NorP) do not remember which. These engine have the Continental tuned induction system, on top, and run cool at 12-13 gph lean of peak. Previous posts regarding the advisability of EGT/CHT on all six cylinders is absolutely correct. Continental has a service bulletin for the procedure to set up the fuel system on their injected engines. I have the IO-550R in my S-35 Bonanza and all compressions are 75+ after 500 hours. Contact John Ackerman 1-800 334 2001 ext 1405 for details. Atlantic Aero has converted several turbo 210's and they have a few 206's with this engine operating out of Juneau on floats. If you try it you will like it!

 

[garyh]

randy,
i would suggest going to www.csobeech.com/peak-engine.html and getting educated on the "dangerous red box" which your cylinders have been visiting at 50* rop unless you're running less than 60% power. also go to www.beechtalk.com and search "red box", both great sights for big engine management and life.

gary