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FlyingMonkey

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Hi Ed,

 

That yellow cottage cheese you got out of the oil cooler may not have been solely in the radiator. Have you pulled the oil pump off? Gone back and flushed out the radiator again in case more cottage cheese came it's way? Do this at your own hangar. Use solvent and air pressure.Do you have about 12" of springs in the oil hose that comes off the top of the oil cooler and returns into the oil pump housing? It's the one that makes almost 180 degree bend. Did you say you re-routed the bottom hose off the bottom of the engine straight out between cyl. 2-4? This would take a new 90 degree oil tank fitting.

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Yes we re-routed and changed the fitting.  My oil cooler has been flushed enough, going through all this stuff a 2nd and 3rd time isn't worth it to me.  Its just a 100hp motor and cooling the oil isn't rocket science.  I can chase down countless 'fixes' that fix nothing or I can get a cooler that is the same size, design and manufacturer with 50% more cooling capacity because it has 50% more rows. 

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I repositioned my cooler a bit yesterday (it was off-center a little to the right), but there is not much adjustability on it and I couldn't change it too much.  I also did a small amount of trim work around the cowl opening; the lower corners were very rounded and seemed to mask the lower corners of the cooler, so I opened it up by squaring off the opening just a bit.  I didn't go crazy on it, I'll just do more incrementally if needed.

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There is a fairly recent SI (912-24 November 2015) that introduces the new oil radiator set (small, medium and large).  The SI mentions that all new engines are equipped with these and the main difference is the "Increase of the number of radiator fins".  Presumably, this improves the cooling.  Yes -- I know that the vast majority of installations don't have cooling challenges but it appears Rotax has made improvements, and, probably for a reason.  Just my $0.02.

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I repositioned my cooler a bit yesterday (it was off-center a little to the right), but there is not much adjustability on it and I couldn't change it too much.  I also did a small amount of trim work around the cowl opening; the lower corners were very rounded and seemed to mask the lower corners of the cooler, so I opened it up by squaring off the opening just a bit.  I didn't go crazy on it, I'll just do more incrementally if needed.

 

Not too squared off I hope. Easier for cracks to form.

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Food for thought...

 

Cowling openings and baffling are - or should be - pretty carefully thought out by the manufacturer.

 

Often they use what seem like smallish openings to benefit from the venturi effect of increased air velocity through a narrowed opening.

 

Not saying that's the case, but beware unintended consequences - just opening up a cowling may or may not increase air flow at any given point within the cowling.

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Food for thought...

 

Cowling openings and baffling are - or should be - pretty carefully thought out by the manufacturer.

 

Often they use what seem like smallish openings to benefit from the venturi effect of increased air velocity through a narrowed opening.

 

Not saying that's the case, but beware unintended consequences - just opening up a cowling may or may not increase air flow at any given point within the cowling.

 

Agree with this...messing with the cowling or other parts of the airframe is a risk.  Taking off the wheelpants is one thing, carving out parts of the radiator opening or altering naca vents is a different animal.

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With interlocking carbon fiber you should have no cracks. I kept mine with the same formation just opened it up a little more on the sides and more on the bottom lip. It made a difference. The rubber skirt around it must be in contact with the cowl sides to force air through the the cooler and not allow it around it. I also made sure my cooler was pulled all the way forward on the bottom edge to face as much into the air flow as possible. My OAT's are higher than many of you and I have no over heating issues.

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Many of us had 'no issues' at first. John Horn and myself to name 2.  We had this glorious condition with the original cowl opening. Roger,  you like to point out that other CTs like yours have no issues so there must be something wrong with ours.

 

On one hand I want to say we can rule out the cowl opening because we had max 230*F performance in our first year(s). On the other hand you must have modified your cowl for a reason and that reason is obviously to enhance the cooler's performance.  The fact that you are doing mods on your cowl argue in favor of the cooler needing more capacity in spite of what you say.

 

Your CT getting hot?  Here we go, springs, out, new oil hose fitting and new routing, remove oil pump and inspect, re position coolers, do a flush, check rubber seals, springs back in and modify your cowling.

 

Don't upgrade the cooler, just fix what is wrong with your plane!  Note:  all of the above will be fun to do but none of them will fix your new problem :(

 

Note:  I have flown 4 other planes and all of them in over 100*F conditions and the CT is the only one where cooling oil is even an issue at all.

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I'm saying if your engine went from a climb temp of 230F+/- to 260F+ then something changed and it isn't just because the engine has more time.

 

If your oil temps changed something changed otherwise all our engines and other Rotax engines would be reporting the same. The huge majority of the CT's also don't have the problem.

 

You still may have missed something or the mechanic missed something that you think was done well. Maybe a second set of eyes and a different mechanic might make a difference. Everyone misses something sooner or later. I have, but I never give up.

 

My cowl opening enlargement was a research test. It made a 10F-12F reduction.

 

Temps just don't change for no reason.

 

Here is what I believe about myself and others. If you can't be critical about yourself and admit you may have missed something or failed you will always leave yourself open to fail, but never learn or recover. If you can admit failure you can conquer it.

 

Sometimes starting back at square one with fresh eyes makes all the difference.

 

My personal creed to live by:

Never say never and never give up.

If I had thrown in the towel as a paramedic some people would never have gotten to the hospital or left it.

 

Remember what Yoda said:

There is no try, only do. :)LOL

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Roger,

 

We are talking 4 mechanics and 8 years of looking and that includes 8 years of following your instructions.  BTW your instructions do change over time but you will never believe that.   ;)

 

I agree temps don't change for no reason.  I don't agree that the vast majority of CTs don't have an issue I believe the majority fly in conditions that don't challenge their cooling capacity.  I also don't agree that all Rotax engines run the same or even that a given engine doesn't change over time.  There is to much evidence to support that there is wide variance.

 

The far west presents high temps and high mountains that block your routes, we have to climb.  We have Wayne in Southern California, he's ready to upgrade his cooler because he can't climb out of SoCAL due to oil temp.  Farther north we have me and farther north we have John Horne.  All of us have CTs from the same year, 2006 and all of our CTs have become either problematic or at least less pleasant to own and fly.

 

My CT is capable of sustaining a decent climb rate with the power provided by ULS.  All we want is the ability to use that power when needed.

 

Think about this, every one of your fixes are not fixes at all.  Pick from your list, any item you want and you can find CTs out of your 'vast majority' that are not benefiting from that particular 'fix' and yet they have no issue.

 

Since there isn't a 'fix' that 'works' I'll go for an increase in cooler capacity.

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I wish you the best and hope it works for you.

 

 

"BTW your instructions do change over time but you will never believe that."

 

You're right. Only a fool fails to learn and change with new knowledge, schooling and experience.

 

"All of us have CTs from the same year, 2006 and all of our CTs have become either problematic or at least less pleasant to own and fly"

 

Sounds pretty jaded and that isn't true. Mine is better now than it was new. Many still love their 2006's. I prefer the SW over the LS.

 

"Think about this, every one of your fixes are not fixes at all."

 

You're right. They are diagnostic eliminations and a means to an end.

 

Good A,B,C diagnostics is everything or you may never find the problem and spend money that was not needed. I'm on the phone 6-8 times a day from around the world doing just that. I have performed those items I listed and several lost 10-15F.

 

Throwing money and labor at something with a poor understanding of the system or a poor plan is usually a setup for expensive frustrating sleepless nights.

It's all in the details and not the motion.

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The changes made to my cowl are really minor.  As I said, you probably would not be able to tell by just looking at it.  I'm a bit skeptical on the re-position of the cooler...there just is not much play there to make as big a shift as I think I need.  I did bend the metal skirt that supports the rubber seal upward a bit to make sure it directs the air better into the cooler.  I think all of these tiny changes together will help.  I checked the oil lines and didn't see any kinks; Roger is doing a Rotax hose change for me in October, so I'll get him to reroute and add springs as he sees fit at that time.

 

I don't need too much more cooling, but I'd like to get to the point where I don't exceed 235°F in a climb, even on a hot day.  That would be a 10-15°F drop over current temps. 

 

I don't recall having any cooling concerns at all, in any weather, until last summer.  Going to Oshkosh with two people it was was getting to 240°F in the climb, and this year it seems to be running a tad hotter still.  But this summer has been a scorcher, so I'm not ready to call this a "real" problem just yet.  But talking to Bill Ince, who lives a couple of hundred miles south of me, his temps are 10-15°F cooler than mine, so I'd like to make up the difference.

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Hi Andy,

 

The only reason I mention the cooler position is because I have had some come in here with it pushed more to one side or the brackets that hold the cooler to the engine are pushed back and have the cooler at an extra downward tilt. Both these are correctable to allow the cooler to be more square in the opening and more forward facing to allow the air to flow through the fins more efficiently.

Every little things adds to the sum of the total solution. 10F is a fairly small change abd can easily be instrumentation and or senders. These systems were not designed to be so accurate as to read down to the last tenth. Looking fro trends and extreme highs and lows would be better observed. If you are in the 235F ballpark in the summer months it might not be improvable. 

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I hear you Roger.  My cooler is more to the right than perfectly centered, and the left is closer to the opening that the right.  I see easily how to adjust left/right (though as I said, not too much play there).  Not sure how the fore/aft is set, the bottom of my cooler could probably benefit by coming forward 1/2" to 1".

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" All of us have CTs from the same year, 2006 and all of our CTs have become either problematic or at least less pleasant to own and fly."

 

I'm out of town and went to bed late last night. I was troubled by this comment. In 2006 FD sold over 100 CT's and in 2007 sold over a 100 CT's. With approximately 360+/- CT's in the US and who knows worldwide that would be almost two thirds of the fleet are unhappy. That just isn't happening.

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Hi Andy,

 

The only thing that holds and controls the fore and aft cooler position is the bracket under the engine that connects to a rubber isolator. Some times this can be moved other times it's as far forward as possible. It would be a snap to make a small extension if one was a little too far back which would allow the cooler bottom to swing more forward and sit more squarely in the openings and into the air flow. This may be all some people need. Too much downward angle on the cooler fins would impede air  flow.

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" All of us have CTs from the same year, 2006 and all of our CTs have become either problematic or at least less pleasant to own and fly."

 

I'm out of town and went to bed late last night. I was troubled by this comment. In 2006 FD sold over 100 CT's and in 2007 sold over a 100 CT's. With approximately 360+/- CT's in the US and who knows worldwide that would be almost two thirds of the fleet are unhappy. That just isn't happening.

 

Roger,

 

You are taking my statement out of context.  The context was: 3 of us in the Far west have 06 SW's.  Wayne F., John H. and myself.  " All (3) of us have CTs from the same year, 2006 and all of our CTs have become either problematic or at least less pleasant to own and fly."

 

I was never referring to the whole fleet, just 3 examples of pilot/06 SW owners who live on the west coast and all 3 or our CTs now have inadequate cooling

 

When I look at the 3 profiles and the amount of time, effort and money that the 3 of us have put into this issue for 8 years and counting, I suspect our problem lies more with the design than the owners.

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ED,

 

I'm not trying to jab you, but hopefully help you to a less expensive permanent solution they may have been overlooked.

 

Then I take back my comment, but still only 3 out of over 200+ of the same model for the years 2006-07.

 

The pattern here is still only an extremely small number so it becomes find the cause. 98% of Rotax engine issues are owner or mechanic caused. There is a cause and I couldn't walk away from that. Like they say: adapt, overcome and per savior.

I just cured one a couple of months ago. It was partial owner and 2-3 mechanics with poor diagnostic skills that didn't start at the beginning and follow it through in a logical and detailed problem solving progression so they overlooked a tiny reduction in an aluminum tube that was on an LS with a Franz thermostat. They looked and fought for months and threw money at the wrong things. Took me about 20 minutes.

 

Like I said maybe a new set of schooled and experienced eyes may find the problem.

 

Fresh eyes and minds can make a difference. When I hit a wall I start asking other people for their thoughts. They may have seen something I haven't or look at it from a different perspective.

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 only 3 out of over 200+ of the same model for the years 2006-07.

 

...

 

When I hit a wall I start asking other people for their thoughts. They may have seen something I haven't or look at it from a different perspective.

 

 

No that's 3 out of 3, you don't get to call the other 200+ free from higher oil temps.  What about Andy?  Didn't we just learn that he is inexplicably 10-15* hotter than Bill?

 

We hit this wall 8 years ago and have asked all the other people.  Problem is nobody has a solution that has made our planes back to new.  Not only do I have better things to do but I want back what I test flew.  Woodstock could outperform my old 180hp 172 by a huge margin and I want that back.  I'm now convinced I'm not getting that back without doing something new.

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Andy isn't over heating. Running up to 240-245f isn't over heating. Running warmer than the next guy is controlled by other variables. i.e. Prop pitch, pilot technique, OAT, cruise rpm, ect... Each one needs to be evaluated individually and all aspects ruled in or out. This is exactly what a GOOD Doctor does. You walk in just like the last guy. Anything may be wrong and you may have a symptom or two the same. Through GOOD diagnostic history taking the Doc. Determines what's wrong and they may be totally two different things. Something like a cold, allergies or sinus infection. All three different, but with the same symptoms.

 

 

It isn't a simple one item fix all.

 

You have to deal with each one on a separate basis. No two are alike, but doing enough of these teaches you what to look for and how to rule in or out certain items.

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