UL260si, what do ya' think?


16 posts in this topic

Posted

Howdy Boys!

I've got my horses, garage organized, and I'm gonna start buildin'wings. I've been lookin' at powerplants for this plane and have been lookin real hard at the UL260is. I defiantly want to hang a 4 stroke on now, for I think, obvious reasons, and the UL sounds like a very good engine. Has anyone out there installed one or heard about anyone who has put one on an Avid C like mine? Air cooled, fuel injected, direct drive and more, make it quite attractive. Evidentially, they're gonna start puttin' them on Kitfoxes! I have concerns though. It weighs 159lbs and at 107hp, is that too much for an Avid C? Do ya' think it would fit under a conventional cowling off of a Mk 4? I do not know! I am wanting to make a cowling swap with chopndrag down in Florida, his conventional (Cessna style) for my round cowling. Surely, if you can fit a 912 under there you could fit a UL. Heck, they've fit 0-200's haven't they? Chopndrag is pretty hot on my round cowl, and well, I wouldn't mind taking a trip down there! 

I do know I'm gettin' the cart way of the horse here, but I do like to have a plan. As I build my kit, I'll post pictures and my many questions under the Model C section. Yes, I already got questions galore for you guys!!!! I'll post'em. Post 'em?.....Hmmmm I feel like a computer nerd.

Wyatt

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Posted

A friend of mine has a UL260i on his Zenith CH701. I did the electrical install. I have a couple of concerns and observations regarding this power plant install.

The engine is beautifully made. The machine work, fit and finish is impeccable. The components are located in convenient locations for installation and maintenance. The mechanical installation was straight forward and relatively uncomplicated. Performance is remarkable and fuel consumption is very low around 4 - 5 gph.

My concern: The entire operational package relies upon an uninterrupted electrical supply above 12 volts at full operational amperage.  The FADEC, digitally controlled electronic ignition, digitally controlled electronic fuel injection, dual electrically switchable fuel delivery and return system is very complicated and very sensitive to considerable electrical supply requirements. 

My friend has already had one off field forced landing due to a low voltage condition, 11.8vdc, caused by a loss of adequate charging current. One phase of the 3 phase rectifier/regulator failed causing inadequate charging current to maintain battery voltage at 12v or better under full operational load which caused a breaker supplying the ECU to open.  Fortunately the landing was in a recently mowed and hayed field with no damage to the airplane.  After charging the battery from an external source and resetting the open breaker the airplane was able to be flown back to the airport and returned to the hanger. 

We replaced the rectifier / regulator unit.  We also installed a separate switch/breaker for the ECU fed directly off the battery isolation solenoid. He has experienced another low voltage condition but noticed it before the ECU cut out and immediately returned to the airport.  We could not determine what caused the low voltage event.  He has now reset the alarm set point to alarm if voltage drops below 12.5v indicating a low charging condition. Testing and cautious flying is ongoing. The initial low voltage failure occurred around 100 hours total time and he has flown an additional 20 hours under testing conditions.

The airplane has a small gel cell lead acid battery installed and relies heavily on the charging coil rectifier/regulator to provide electrical power needs.  Due to the power requirement of the ECU and other electrical equipment the battery will only last less than 30 minutes if the charging capability fails. In my opinion this is a single point failure weakness of this installation.  Other than that I think the UL is a great power plant, I just wish the engine had a mag as a backup to the ECU.

MarkD

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Posted

Thanks Mark!

I see, electronic ignition, so no independent fire like you would have with mags. If you have mags and the alternator quits spittin' out power, she's gonna run. Electronic ignition on a UL, alternator quits and once the battery goes flat, ya' lose fuel flow and she'll quit you. And like you were sayin, even a problem in the circuitry or components and it's done. Sound right? Did y'all talk to them about it and what did they say? These are relatively new engines on the market, so I'll bet there's bugs. It's a while before I have to make a decision what powerplant to use, but I'm keepin' my eyes open. Thanks again! 

Wyatt

 

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Posted

Actually factory support from both RANs and UL has been spot on.  When we replaced the voltage regulator it was mailed out immediately and arrived within a couple of days first class mail. We installed a separate breaker/switch for the ECU directly off the terminal from the battery isolation solenoid at their suggestion. The technical staff at UL has been very responsive to questions and reports of difficulties.  So far they seem to be good folks interested in their product and supporting their customers.

You are correct, any interruption in the electrical system and the silence from the engine will be your first indication of a problem.

I tell my friend "Do not fly where you cannot land".  I do the same in my Avid.

MarkD 

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Posted

Thanks Mark!

Was this engine the 97 or the 107hp (260i or 260is)? A very attractive feature of the UL is that Wicks Aircraft is the national parts supplier and the dealer is just over in Missouri. I live in Shelbyville, Illinois, about 70 miles from Wicks. 

In your opinion, does this engine have too much power for an Avid C?

Wyatt

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Posted

How much $$?

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Posted

An engine review in Kitplanes list the 260i for 18K, the iS for 19K. A lot!

Wyatt

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Posted

Better performance for less money from a 912...

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Posted

A 912 is lighter too! What I find more attractive is the direct drive and fuel injection.

Wyatt

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Posted

I don't mean to sound snippy, but, why do you prefer fuel injection and direct drive?

Injection is infinitely more complicated and Rotax has a track record of millions of trouble free hours on their gearboxes which allow a larger, more efficient prop. 

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Posted

I do want to get away from 2 stroke on my build. A good friend has been on me pretty hard! Yes, a 912 would definitely foot the bill and, fact of the matter, I'm a heck of a long way from buying a engine. The only thing I don't like about Rotax is, they turn such a high RPM. I am getting the cart in front of the horse here, but it don't hurt to talk about it. There's a helluva bunch of options out there! There was another thing about that UL that I like, it's air cooled!

And I do very much appreciate your input! Thanks!

Wyatt

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Posted

I am toying with the idea of the Yamaha YG2, YG3 or YG4 engines just trying to figure the best combo for my Mk4 HH.

Dave in Western IL

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Posted

Wyatt, the engine I have described is the 97HP engine.  I'm not sure I understand the concept of "Too much power." I think it depends largely on how the airplane will be exercised. If the plane will be used on floats or in high altitude applications the additional power may be useful. If only used from paved 6000ft runways at sea-level the additional power may not be utilized often unless one get a rush from 2000fpm near vertical climbs. (That would be cool.) One disadvantage of the UL is the relatively short prop for a bush type of aircraft with a limiting VNE.  For my personal flying style I would prefer a carburetor and magneto (ducati ignition is same as a mag) as standard equipment.  I think the FADEC is too complicated and relies too heavily on external equipment and electrical reliability for a bush plane.  The argument has been presented that most automobiles are electronic fuel injection electronic ignition and they do not fail that often. True, but, they have the side of the road to pull over on...there is no side of the sky. So much for opinions...pick what works for you and makes you feel comfortable.

MarkD

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Posted

By definition, an engine is a machine of insufficient power.

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Posted

I don't understand why so many people are scared of 5800 rpm. NASCAR engines turn 8000 rpm all day. I ran all the way to 16,000 rpm on my dirt bike. The Yamaha 4-strokes are running over 10,000. Rpm is irrelevant as long as the engine was engineered and designed to do it. Have you put any time behind a 912? They are 10x smoother and quieter than any lycoming I've flown. Sorry but the rpm statement always strikes a nerve with me. I've seen too many people ruin these airplanes using a boat anchor of an engine simply because it was direct drive. Spinning a big prop is absolutely key to making a light 100mph perform like it was intended to do. 

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Posted

Amen, Joey.

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