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ULPower

Mike Houston

Active Member
These guys seem to have an increasingly relevant set of engines. going from 97 HP. to the soon to be released 520 Turbo which will have power to 220HP. The engines are FADEC controlled and burn mogas with upto 15% ethanol.

They seem to have a Lycoming replacement for everything upto a IO-390-exp. The 520 replacement for a 390 is also about 60-70lbs lighter
 
They do indeed have an increasingly-broad lineup, and pretty modern as well. But they're priced even higher than a Lycosaur, from what I've seen, which IMO will really inhibit their market penetration.
 
We seriously considered going with them for our 7 build. They have a complete firewall forward kit they can sell you as well to make the cowl, mount, etc. easy to get in place. We really liked the idea of FADEC control, and paired with an electric CS prop from whirlwind makes its even nicer. We only decided against it because after some research, there were quite a few reports of people having to replace jugs fairly early in the engine life. It's likely a non-issue, but for my first plane was a bit much to tackle. I would seriously consider them again for our next plane.
 
They also turn a higher rpm, which will have implications for your propeller choice.

And I think that some of them, at least, aren't set up for constant-speed props.

Dave
 
They also turn a higher rpm, which will have implications for your propeller choice.

And I think that some of them, at least, aren't set up for constant-speed props.

Dave

Yes the 520 is was 3300 rpm for 200HP, at 2800 it gets 185 HP. I think the latest 520 turbo though will give you 220 HP @2700 rpm, at least according to the video below. This would be a rocket machine at 7,000 ft and above.

https://youtu.be/8cNmJATqNsw
 
I've never found any good fuel burn numbers for these engines. I think I remember something like 350f max CHT? Beings an air cooled engine, I had heard it takes lots of fuel to keep the engine cool, thus high fuel burn. I haven't been able to substantiate that rumor, though.
 
I would imagine the fuel burn would be the same or less than an equivalent power lycoming. The block is forged and machined aluminum, which is a better heat conductor than the cast iron blocks on most motors. The heads and cooling fins are modern designs. The FADEC system is a closed loop EFI system. Its got all the relatively modern advances of most car engines. Aluminum car engines have a lower temperature limit than their cast iron counterparts of yester-year as well (at least my old iron heads never warped when they got hot, but the aluminum ones sure did), but a 200 hp civic gets much better gas mileage than a 200 hp small block chevy from the 50's.

The HP ratings thing through me off at first as well, since they advertise power at RPMs you can't achieve with standard props. If you want to use a standard prop, then just assume the motor makes 185hp and compare it to a standard 180hp lyc. You get the same power for about 100 lbs less. If you don't mind going with a new prop design, whirlwind makes props for these motors that are rated to 3300 rpm. So now you can have 200+ hp and still save 100 lbs.
 
What kind of guidance does UL have on how to set up a redundant electrical system for the FADEC system? Electrical dependency for engines gives me the willies.
 
What kind of guidance does UL have on how to set up a redundant electrical system for the FADEC system? Electrical dependency for engines gives me the willies.

They offer a back-up FADEC, but so far, there's not been a reported failure in the field.
 
They offer a back-up FADEC, but so far, there's not been a reported failure in the field.

That's fine, but how are they powered? What about the rest of the wiring, redundant batteries, dual alternators, etc. If it turns into a glider when you shut the master switch off, that's a problem. Just curious if they offer guidance on how to avoid that.
 
If it turns into a glider when you shut the master switch off, that's a problem.

Ehhh... maybe, but I'm not so sure about that. Let me tell you why I say that...

I have an electrically dependent airplane - I need voltage for fuel pressure and ignition, not to mention nav. In my airplane I have dual alternators and a large battery. Either alternator can take the full electrical load of the airplane, and the battery is good for about 30 minutes with both alternators offline, in an IFR flight condition. The Skyview EFIS has its own backup battery and happily proceed on its own for 45+ minutes. So far, so good - that covers my risk assessment for electrical redundancy, others will vary but this is mine. Alternator failures occur, but rarely - and if I have a single flight that has TWO of them, and I can't get it down in the time remaining on the battery, then Jesus loves me and I ain't gonna fight that.

I have redundant power paths to my fuel pumps and ignition, completely separate from the normal path through the master. I can power those items normally through the master or from a hot E-buss directly from the battery with the master off - but I do NOT have them set up for automatic transfer, intentionally. If something goes that far wrong in the cockpit such that there is an electrical fire/smoke, or worse yet a major fuel leakage in the cockpit, then I *DO* want to be able to hit the master and make everything go quiet, and then troubleshoot critical systems one by one as I bring them back online - and yes I'm including engine power in that statement. If I blow a fuel line at the fuel pumps and start dumping raw fuel in the cockpit, I'm going to go cold and deadstick it somewhere in the interest of not making ANY spark and turning myself into a shooting star.

I suppose it comes down to a comfort level with airborne "emergencies" of various levels and how we each deal with them. I've had a few over the last couple decades. I do NOT want to be in a situation where a device fails, the automatic failsafe takes over and puts the backup on line, and somehow I am not alerted to that fact or miss an indication of it. If I have to take positive action to bring the backup online then I know what I have operating and what I don't and there's not a question of whether I missed it or not. When things start to go "nonstandard" in the cockpit, in my mind I will treat it as "minor" which means "Huhhh, it shouldn't be doing that, let's see here...." or "major" which means too many things are going wrong to troubleshoot simultaneously or the issue is too major to troubleshoot immediately - in which case I want to kill the master, stop EVERYTHING, turn the airplane into a glider which follows the known physics of flight, and then take stock of what we know still works. Preferably prioritizing the engine first.

Everyone is different, and we have different risk profiles, this is mine. I've seen me react under pressure enough times to know what to expect. I know precisely how I will react when cruising along at 15,000' and the engine quits unexpectedly - because I've done it. YMMV.

But, I digress.... This is about UL Power, which is something I like and want to see succeed.
 
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What kind of guidance does UL have on how to set up a redundant electrical system for the FADEC system? Electrical dependency for engines gives me the willies.

There are quite a number of electrically dependent certified aircraft out there now- many of the Diamond diesels with FADECs for instance and some of the latest turbines have no mechanical backups for the FADECs either.

We've got a couple thousand people flying our EFI/ EI systems going out 25 years now. Not a big issue if you have a well thought out and constructed electrical systems.

I worry more about the reliability of the spinning ironmongery out front.
 
<< Just curious if they offer guidance on how to avoid that. >>

The short answer is "yes" - the UL Power installation manual includes various sample installation diagrams for single/dual ECU setups, etc.
 
Not a big issue if you have a well thought out and constructed electrical systems.

Exactly. I just posted the question here to get people thinking about it. I think the technology is appealing because it's efficient and "modern," but unless it's either self-generating or installed along with a well-planned and executed redundant electrical system, it does add a significant layer of risk. Not only risking the builder, who may know their system inside and out, but also potentially risking subsequent owners who most likely won't have a clue about how it works and how it may fail. Just food for thought.
 
I would imagine the fuel burn would be the same or less than an equivalent power lycoming.

Pilots can run a Lycoming LOP (lean of peak) for high efficiency and clean running. That isn't an option with the UL Power engines since the FADEC controls the mixture. So far, Lycoming engines run better fuel burns.
 
There are quite a number of electrically dependent certified aircraft out there now- many of the Diamond diesels with FADECs for instance and some of the latest turbines have no mechanical backups for the FADECs either.

One of the Diamond diesel twins a while back had both engines quit after takeoff because the pilots jump-started the plane after leaving the master on and it didn't have enough electrical power to run the ECUs... so it can happen with certified aircraft too. The pilots lack of knowledge/ignoring the POH didn't help...

https://www.aviationconsumer.com/industry-news/fate-1-fadec-0/
 
One of the Diamond diesel twins a while back had both engines quit after takeoff because the pilots jump-started the plane after leaving the master on and it didn't have enough electrical power to run the ECUs... so it can happen with certified aircraft too. The pilots lack of knowledge/ignoring the POH didn't help...

https://www.aviationconsumer.com/industry-news/fate-1-fadec-0/

Yes, that was a famous one but you can't blame the system design there any more than you can blame the fuel system for someone running out of fuel, forgetting to switch tanks or failing to use carb heat properly. All can lead to a power loss at an inconvenient time.

Ignore proper training, systems understanding, POH warnings and checklists at your peril...

Not having solid backup power and proper low voltage warning systems can bite you with electrically dependent aircraft. We suggest all our clients have such things installed.
 
That's fine, but how are they powered? What about the rest of the wiring, redundant batteries, dual alternators, etc. If it turns into a glider when you shut the master switch off, that's a problem. Just curious if they offer guidance on how to avoid that.

Why would you wire the engine computer through the master switch? You don't wire other ignition switches through the master.

The internal alternator feeds the CPU.
 
Why would you wire the engine computer through the master switch? You don't wire other ignition switches through the master.

The internal alternator feeds the CPU.

What I meant was, what happens when electrical power is killed to the aircraft. Say you have to shut off the master due to smoke in the cockpit, for example. Will it keep running as if it had mags/carb? Looks like it will if you use their special buffer capacitor, since the ECU is wired to the regulator/rectifier and alternator.

It's a single-alternator, single-battery system, according to the UL Power website. If you have an alternator failure, it will run until the battery dies, about an hour on the battery they tested. If the battery dies first, it runs "as long as necessary" on alternator power... or until the alternator burns out. That's fine for a VFR airplane, but if you're putting one of these in an RV intended for IFR, is that battery or alternator going to last until you're in a position to land? These engines were modeled after Jabiru engines. The alternators are basically motorcycle stators. The drawing on the UL site is identical to a Jabiru system with the stator and rectifier/regulator. I've seen them fail quite a bit. They burn out, regulators go bad. Maybe UL has improved them? People need to be prepared, is all I'm saying. I don't have a dog in the engine fight anymore, thank God. In fact, my old friend/colleague sells both Jabiru engines and UL Power. Those ULs do look sexy. But I cringe when people get all starry-eyed over the new technology and assume that it won't fail. I'd want a dual-alternator, dual-battery setup on one of these, personally. It would help offset the weight difference, too... :)
 
What I meant was, what happens when electrical power is killed to the aircraft. Say you have to shut off the master due to smoke in the cockpit, for example. Will it keep running as if it had mags/carb? Looks like it will if you use their special buffer capacitor, since the ECU is wired to the regulator/rectifier and alternator.

It's a single-alternator, single-battery system, according to the UL Power website. If you have an alternator failure, it will run until the battery dies, about an hour on the battery they tested. If the battery dies first, it runs "as long as necessary" on alternator power... or until the alternator burns out. That's fine for a VFR airplane, but if you're putting one of these in an RV intended for IFR, is that battery or alternator going to last until you're in a position to land? These engines were modeled after Jabiru engines. The alternators are basically motorcycle stators. The drawing on the UL site is identical to a Jabiru system with the stator and rectifier/regulator. I've seen them fail quite a bit. They burn out, regulators go bad. Maybe UL has improved them? People need to be prepared, is all I'm saying. I don't have a dog in the engine fight anymore, thank God. In fact, my old friend/colleague sells both Jabiru engines and UL Power. Those ULs do look sexy. But I cringe when people get all starry-eyed over the new technology and assume that it won't fail. I'd want a dual-alternator, dual-battery setup on one of these, personally. It would help offset the weight difference, too... :)

I agree, you are totally correct that these engines (and any other ED engine) should have a backup power source whether that be another battery, alternator or both.

Most often we wire the backup power so the engine can continue to run with the master contactor open though there are many ideas on how to accomplish backup power and not all follow this concept.
 
It's rare that I can do much other than read these threads and absorb information. Perhaps that's changing...

I'm peripherally involved in an aircraft equipped with a Rotax 912 iS engine. Rotax appears to have given much thought to the topic of redundancy in an electrically dependent aircraft.

The iS engine has two engine management systems called Lane A and Lane B. It has two alternators, A and B, either of which can power the EMSs. It's a well-designed system from what I can see. What I find interesting is there is also an opportunity to provide a third source of power to the EMSs from the ships battery, thus giving triple redundancy.

The only aspect of this implementation that causes me a little consternation is that some engine indications are not available to the pilot when operating on just one of the two EMSs. Seems a tolerable situation when one considers the EMS will keep the engine running.

In speaking with a certified Rotax iS engine tech I learned that Rotax has plumbed the engine with far more sensors than it currently uses to manage the engine, sensors like knock sensors. Clearly they have built the engine with future development in mind.

Interestingly, the design philosophy of the engine (and the basis of its certification) is that the pilot gets power when (s)he commands it. The EMS will not retard power to protect the engine. This is a fact a pilot is best to keep in mind, both in light of preserving the lifespan of the engine but also in preserving his or her own life when the trees are fast approaching.
 
Not everybody has has good experiences with the iS EMS. They had a some issues initially with the system giving uncommanded power reductions in service. I don't hear much about that any more though.

We're working with an iS owner now to remove the factory EMS and replace its eyewatering complexity with SDS.

We've been approached by 2 UL engine owners also to replace their factory EMS' as they were not happy with several aspects of them.
 
I don't think their FADEC runs in closed loop. No mention of an O2 sensor on their website.

There isn't a mention of an O2 sensor on the site, but the kitplanes article about the motors says if you lose a sensor they run a richer fuel map. I think your right theres no closed loop control, just different open loop fuel maps based on failed sensor flags.

Pilots can run a Lycoming LOP (lean of peak) for high efficiency and clean running. That isn't an option with the UL Power engines since the FADEC controls the mixture. So far, Lycoming engines run better fuel burns.

Do you have any source for this? The article I read about the smaller UL engines says they get better fuel efficiency than a similar powered rotax, which in turn are more fuel efficient than lycoming running similar power settings. It would be awesome to have some actual data from all the engines. Also, just because it's fadec controlled doesn't mean you can't tune it LOP off high power settings. Every ECU I've programmed goes way lean in the high RPM/low load area of the map.
 
Works our to around .45 lbs./hp/hr. at 100 hp. Nothing impressive for a modern design. A Lycoming can do around .40-.42 with fuel injection running LOP.
 
Fuel

Works our to around .45 lbs./hp/hr. at 100 hp. Nothing impressive for a modern design. A Lycoming can do around .40-.42 with fuel injection running LOP.

The problem with the lycoming is it only burns LL100. The ULpower burns Mogas with up to 15% ethanol. In Europe that saves you about $3.50 a gallon.
 
The problem with the lycoming is it only burns LL100. The ULpower burns Mogas with up to 15% ethanol. In Europe that saves you about $3.50 a gallon.

730 hours so far on a 360 burning Walmart-grade 91 premium with ethanol. Most people don't do it - but that doesn't mean it can't be done.
 
730 hours so far on a 360 burning Walmart-grade 91 premium with ethanol. Most people don't do it - but that doesn't mean it can't be done.

Yes, the 360s have a compression ratio of 8.5:1 which seems to be tolerant to burning mogas. Unfortunately the 390s are all higher though it appears if you are building an RV10 the 540s probably work with mogas as they are all 8.5 :1
 
Yes, the 360s have a compression ratio of 8.5:1 which seems to be tolerant to burning mogas. Unfortunately the 390s are all higher though it appears if you are building an RV10 the 540s probably work with mogas as they are all 8.5 :1

I'm not running 8.5 pistons.

Again, you preach what you do not know. You can learn a lot more by asking questions than stating what you believe to be true. The world we live in is not black and white. In many cases the answer is "it depends" and you're going to have to learn some things to go further.
 
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I'm not running 8.5 pistons.

Again, you preach what you do not know. You can learn a lot more by asking questions than stating what you believe to be true. The world we live in is not black and white. In many cases the answer is "it depends" and you're going to have to learn some things to go further.

Everything he wrote was reasonable. He did make (and clearly state) the assumption that most 360's and 540's have standard 8.5:1 compression. That doesn't seem like a good reason to cut him off at the knees.
 
Everything he wrote was reasonable. He did make (and clearly state) the assumption that most 360's and 540's have standard 8.5:1 compression. That doesn't seem like a good reason to cut him off at the knees.

Ok, fair enough, let's try another run at this.

First off, I like the UL Power products, I'm not running one myself but I would (will?) certainly consider it on my next build. I think they have a good thing going there and the aviation market needs more choices for powerplants. But trying to justify or cheerlead for UL Power because they can burn mogas or cargas while Lycomings can't is simply not true. It's also not true that only Lycomings with 8.5:1 compression can burn mogas/car-gas.

The issue of burning non-100LL fuels in our large-bore slow turning engines is a multi-faceted beast that requires a fair deal of education, some good instrumentation, and in most cases some fuel system modification. It can be done - but not painlessly. You'll have to invest a few dollars and a whole lot of hours of research, but it can be done.

Yesterday I took off in my plane fueled with Walmart 91 premium car gas with ethanol, climbed direct to 17,000 feet running 29 degrees of timing and lean of peak the whole way - and my engine stubbornly refused to melt down. How did that happen? There are still a few tricks, you see...

https://flightaware.com/live/flight/N16GN/history/20210131/1650Z/73XS/KPIL

To the OP - I do apologize for coming across a little harsh, I'm edging into cranky old curmudgeon "Get off my lawn" territory these days. I need less coffee and more patience.
 
Thought I'd chime in for some unanswered questions.

That's fine, but how are they powered? What about the rest of the wiring, redundant batteries, dual alternators, etc. If it turns into a glider when you shut the master switch off, that's a problem. Just curious if they offer guidance on how to avoid that.

The alternator is a permanent magnet unit; it is a 30A or 50A (depending on your option) alternator produced by Cycle Electric in Ohio. From personal experience I can tell you that you can shut off the battery master and keep churning along just fine. If you trust magnetos, then you should be happy with this alternator; it's dirt simple. The alternator is literally a ring of magnets spinning around stator poles mounted on the end of the crankshaft. There are no gears or belts to fail. If the crankshaft is turning, the alternator is running.


No, it is not a closed loop system and does not use an O2 sensor. On my 2013 vintage UL350iS, fuel mixture is determined using throttle position, oil temp, air temp, fuel pressure, atmospheric pressure, and rpm.

Each of the inputs does have a default setting so that in the event of one or more of their failures, a fail-safe mixture is produced. I've tested this and it is a fairly rich mixture.
 
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According to UL Power web site, the UL520T develops 220hp at 2700 rpm. And it maintains 220hp up to 15000 feet. It is about 100lbs lighter then IO-540. The IO-540 has somewhat HP advantage only up to approximately 5500 ft, even less than that considering it is much heavier than UL520T.

If I am to build RV-10, the UL520T looks to me a better choice than IO-540.
 
According to UL Power web site, the UL520T develops 220hp at 2700 rpm. And it maintains 220hp up to 15000 feet. It is about 100lbs lighter then IO-540. The IO-540 has somewhat HP advantage only up to approximately 5500 ft, even less than that considering it is much heavier than UL520T.

If I am to build RV-10, the UL520T looks to me a better choice than IO-540.

Lots of people are installing 9 to 1 CR PV 540s with ported heads, good exhaust and EFI making 290+hp. Turn in 170-175 KTAS speeds up at 15,000 to 17,000 on 10.5-11.5 GPH.

100 pounds less weight up front will involve some major mount and cowling mods, may have an impact on yaw stability as well. Be sure you're ready for those impacts.

Sounds like Adept Engines are pursuing work on getting one of their engines mounted in a -10. May be worth looking at that engine too.
 
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According to UL Power web site, the UL520T develops 220hp at 2700 rpm. And it maintains 220hp up to 15000 feet. It is about 100lbs lighter then IO-540. The IO-540 has somewhat HP advantage only up to approximately 5500 ft, even less than that considering it is much heavier than UL520T.

If I am to build RV-10, the UL520T looks to me a better choice than IO-540.

Reference Mr. Farnham's comments above. The risk/gains/effort equation doesn't make a lot of sense. A straight valve Lycoming with his aforementioned mods can make 210 or more without supercharging or normalizing like the PP you're considering. Yes, it would bring more to the capabilities especially at altitude but there are costs/considerations there too.

Are the potential benefits worth the added work, headache, and current risk? Is the risk of potentially having a future orphaned engine worth it?

Any purchase money saved may very well be exceeded in other costs and efforts. Even though many will state resale value of their aircraft isn't a consideration, some related scrutiny should be considered.

Your build so do as you wish. Keep both eyes open and lots of consideration regarding your choices. Best of luck.
 
Good airplanes are made around a good engine. RV-10 was designed around IO-540. However, new engines are arriving and a 4 seater homebuilt airplanes will have to adapt, the sooner the better. Already on the homebuilt market there are well thought 4 seater airplanes around economical engines, and Van's should take a note.
 
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Sounds like Adept Engines are pursuing work on getting one of their engines mounted in a -10. May be worth looking at that engine too.

Adept Engines are too expensive. For an engine to compete with IO-540 in RV-10, it has to have the same price however, it should offer some savings somehow (better performance or better fuel consumption and etc.).
 
What is the going price for the 520T?
They don't show it on their web site. However, because it comes from Europe, and everything is expensive coming from Europe, my guess would be mid 40k. I hope to see them at this year Oshkosh, then I'll ask them that question.
 
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Your build so do as you wish. Keep both eyes open and lots of consideration regarding your choices. Best of luck.
I don't have expertise nor money and time to complete a complex project such as installing a none standard engine in RV-10. If I decide to build RV-10, I will build it according to Vans prints with, maybe, some mods that are proven by RV-10 community.
 
I know the price for the Adept engines as I've corresponded with them and produced a video about the 320T some time back.

I am interested how the UL will compare. I sent them an email asking pricing a couple days ago. No response yet.
 
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