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UL power new engine option for RV14

Mike Houston

Active Member
? For those who fancy installing an engine designed with mogas in mind and which in theory could give better performance than the I0-390EXP. UL power are now selling their 520T, a 220 HP Turbo charged engine which will be producing 220HP at 15,000 ft. The engine weighs 269lbs with starter and alternator, so about 39lbs less than the Lycoming, i am not sure but i don't think that would upset the COG to much and 5 extra HP at sea level and 40lbs less could get your of the ground a bit quicker and you would have about 50 extra HP at 7000 ft. Whats not to like.

Cheaper Fuel
more power
a little bit lighter

The only potential issue i can see is the dimensions it length is 33.34 versus 30.7 for the EXP, width is 29.28 versus 34.25 for the EXP and height is 21.69 versus 19.35. This engine would have to be of interest to RV14 builders, i wonder if Vans would do a FWF kit for it?

https://ulpower.com/en/engines/ul520/ul520t
 
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Lengthen and narrow the cowling. If you push the engine several inches farther forward you would mitigate the CG issue plus it would look super cool.

Eric
 
? For those who fancy installing an engine designed with mogas in mind and which in theory could give better performance than the I0-390EXP. UL power are now selling their 520T, a 220 HP Turbo charged engine which will be producing 220HP at 15,000 ft. The engine weighs 269lbs with starter and alternator, so about 39lbs less than the Lycoming, i am not sure but i don't think that would upset the COG to much and 5 extra HP at sea level and 40lbs less could get your of the ground a bit quicker and you would have about 50 extra HP at 7000 ft. Whats not to like.

For those that would contemplate this engine, there are a few things I would suggest you do some research on -

39 pounds is approx the weight delta between the parallel valve IO-360 and the IO-390, and Van's has officially stated that the parallel valve engine is too light for the RV-14.

Keeping an engine cool at 15000 ft when it is capable of producing max power at that altitude will require some extensive experimenting and modifications to the cowl and cooling/baffling system on an RV-14 (not to mention the nods that would be required for the likely relocation of the engine to deal with C.G.).

Potential changes in spin recovery if engine is moved fwd to counter C.G. influence.

Higher power at high altitude could be unusable unless you are willing to fly the airplane in untested territory in relation to Vne and flutter margins.

HORSEPOWER LIMITS: WHY NOT A TURBOCHARGED/HIGHER HORSEPOWER ENGINE?
https://www.vansaircraft.com/faq/horsepower-limits-why-not-a-turbocharged-higher-horsepower-engine/
 
You would not have to use full power, and the main bonus is the ability to burn Mogas. A fuel that is cheap and will be in supply for a longtime into the future. I sometimes wonder what the deal is between Vans and Lycoming. If they were interested in customers they would be more open to different engine options which would help their customers.
 
Matter of economics?

I sometimes wonder what the deal is between Vans and Lycoming. If they were interested in customers they would be more open to different engine options which would help their customers.

Methinks it may have something to do with known and proven history/technology.

Consider what it would cost in time and $$ for Vans to develop a FWF package for all of the various engine choices available.

Now, consider how many of the non Lycosauras FWF packages would Vans actually sell.

Lastly, the engine is one of the early design elements that the engineers choose, and that influences the balance of the aircraft design.
 
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You would not have to use full power, and the main bonus is the ability to burn Mogas. A fuel that is cheap and will be in supply for a longtime into the future. I sometimes wonder what the deal is between Vans and Lycoming. If they were interested in customers they would be more open to different engine options which would help their customers.

Van's believes in proven concepts. Aluminum airplanes, Lycoming engines, Rotax engines once they were a mass market item, etc. That's how they bring economies of scale to the market. They don't get that from alternative engines.
 
One of big advantages I see for the T version is that wil get the horsepower @ 2700RPM, instead of the 3300RPM that is applicable for the non-turbo versions.
 
Vans

I think your naive if you don’t think Lycoming and vAns don’t have a sweet heart deal going on. Rotax Only got it’s foot in thru the door because Lycoming didn’t have an engine which was suitable for the RV12.

ULpower have been around since the 2002 and are used regularly in STOL aircraft. They are the engine of choice for the new Dark aero. I agree you can use mogas in some Lycoming but not the 390 without doing some work on the fuel system
 
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Just because you can...

The use of mogas in a lycoming is already documented. What other advantage would it be to have an alternate engine manufacturer?

I would have liked Vans to have used the lycoming from the cessna 162 in the rv12, but i regress.

I would rather Vans work on the high wing Stol high speed cruiser RV15.
 
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The use of mogas in a lycoming is already documented. What other advantage would it be to have an alternate engine manufacturer?

I would have liked Vans to have used the lycoming from the cessna 162 in the rv12, but i regress.

I would rather Vans work on the high wing Stol high speed cruiser RV15.

Well I agree, this engine would be a perfect choice for such a design but I won’t be holding my breath for anything other than a Lycomasarus
 
I think your naive if you don’t think Lycoming and vAns don’t have a sweet heart deal going on. Rotax Only got it’s foot in thru the door because Lycoming didn’t have an engine which was suitable for the RV12.

That sounds kind of sinister....

Seriously, when you design an airplane, you start with an engine. Van has traditionally designed around Lycomings because they are well understood, pretty reliable, plentiful, and available used (for those on a budget and willing to search around). Nothing more sinister than that!

And the good news.....this is experimental aviation! You can install whatever engine you like on the nose of your kit! You’ll just have to do some engineering work, like all homebuilders (including Van) had to do back in the day - so there is nothing stopping you from doing exactly what you ask - as long as you’re willing to do the work. If you want someone else to do the work, you’ll only have to convince that person that it is worth their while.
 
Well I agree there is truth in what you say, however other kit manufacturers try and offer a broader range of engines, see kitfox, zenith, rans. I wish Vans also tried to spread the love to other manufacturers.
 
Well I agree there is truth in what you say, however other kit manufacturers try and offer a broader range of engines, see kitfox, zenith, rans. I wish Vans also tried to spread the love to other manufacturers.

I stay pretty well connected with most of the major manufacturers Mike, and I think “offer” is a fairly generous term. Yes, they will talk with you about different engine options, and for a price, they might even supply an engine mount for a couple of different types. But you’re still pretty much a homebuilder who has to figure out a lot of stuff.
 
I would have liked Vans to have used the lycoming from the cessna 162 in the rv12, but i regress.

There is a very specific reason that would not have been a good choice, and it is at least part of the reason that the 162 was not succesful.

Engine installed weight.

When you have a specific maximum gross weight you have to design too, choices made during the design process where weight increase is also a major influence, must be made very carefully.

As for Van's being in bed with Lycoming, being the reason that only Lyc type engines are used in designs?

I always respond to questions like that with another question......

If an engine manufacturer came along with an engine design that had significant improvements in the hp range of Lyc. currently used in RV's, how many more kits do you think Van's could probably sell because of the advancement? It wouldn't make business sense not to take a close look.

But, by significant, that would mean a mix of any of these - Big reduction in cost, big improvement in power to weight ratio, big improvement in fuel efficiency, while at the same time having a well proven track record of reliability, ability to produce a large volume, a good spare parts network, etc.

At this point in time, there are no other engine manufacturers that can do this. Hopefully that will change some day.

So a special business relationship with Lyc driving the engine choice for Van's Aircraft designs couldn't be further from being true.
 
There is a very specific reason that would not have been a good choice, and it is at least part of the reason that the 162 was not succesful.

Engine installed weight.

When you have a specific maximum gross weight you have to design too, choices made during the design process where weight increase is also a major influence, must be made very carefully.

As for Van's being in bed with Lycoming, being the reason that only Lyc type engines are used in designs?

I always respond to questions like that with another question......

If an engine manufacturer came along with an engine design that had significant improvements in the hp range of Lyc. currently used in RV's, how many more kits do you think Van's could probably sell because of the advancement? It wouldn't make business sense not to take a close look.

But, by significant, that would mean a mix of any of these - Big reduction in cost, big improvement in power to weight ratio, big improvement in fuel efficiency, while at the same time having a well proven track record of reliability, ability to produce a large volume, a good spare parts network, etc.

At this point in time, there are no other engine manufacturers that can do this. Hopefully that will change some day.

So a special business relationship with Lyc driving the engine choice for Van's Aircraft designs couldn't be further from being true.

Well the power to weight ratio on the UL power 520T is clearly superior to the IO-390 EXP. It’s lifetime cost includes fuel and using mogas in plane versus Avgas for 1500 hrs is going to save a customer we’re I come from around $45,000. I am not sure what the asking price is. As far as fuel consumption is concerned I would expect there is not much in it.

It’s sounds like I am having a go at Vans, well I don’t mean to. I suppose I like their planes and kits the best, I just find it frustrating that I can’t get a mogas power plant in the RV14 and I would also like fadec controlled not so important. The UL power plant seems to fill these requirements, however it would be hard to resell if Vans won’t support it, bummer
 
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You sound so convinced that other engine options can’t use auto fuel. There are literally thousands of people doing it so there’s proof that it’s not true.
 
Well the power to weight ratio on the UL power 520T is clearly superior to the IO-390 EXP. It’s lifetime cost includes fuel and using mogas in plane versus Avgas for 1500 hrs is going to save a customer we’re I come from around $45,000. I am not sure what the asking price is. As far as fuel consumption is concerned I would expect there is not much in it.

It’s sounds like I am having a go at Vans, well I don’t mean to. I suppose I like their planes and kits the best, I just find it frustrating that I can’t get a mogas power plant in the RV14 and I would also like fadec controlled not so important. The UL power plant seems to fill these requirements, however it would be hard to resell if Vans won’t support it, bummer

Lots of folks running Mogas in Lycs and you can retrofit EFI and EI easily on a 390. We're done a number of them now.
 
Lots of folks running Mogas in Lycs and you can retrofit EFI and EI easily on a 390. We're done a number of them now.

On this note.... we worked with SDS to configure a package for the -14 and the IO390. We have a complete drop in firewall aft fuel plumbing package as well as a firewall forward fuel plumbing package that will match easily with the SDS system.

The cabin and firewall forward fuel lines are all drop in and are one of the most complete component kits we have built. All the rigid tubes are CNC bent and pre flared. Multiple cnc machined components are also included to make installation easy.

http://www.aircraftspecialty.com/PDF Documents/RV14 DUPLEX.pdf

Above is the link to the firewall aft install.

http://www.aircraftspecialty.com/PDF Documents/FWF SDS RV14.pdf

Above is a link to the firewall forward install.

Please reach out with any questions.

Happy Building,
Steve
 
The UL power plant seems to fill these requirements, however it would be hard to resell if Vans won’t support it, bummer
After you've installed a Lycoming in your RV, Van's doesn't "support" it either. Lycoming does. With a worldwide network of service centers and available parts.

How many people worldwide can look after your ULPower engine after it's installed? How many locations will have parts on the shelf for you when you need them?
 
Vans is willing to chat with customers about alternative engines. They talked with me when I was exploring alternative options for my RV-14. But they only have limited resources so unless you want to spend $1M to pay for the engineer time for them to design you a new firewall forward package for you, then IO-390 is the off the shelf option, with drawings and parts all ready to go.

They are experts with the Lycoming so why would anyone expect them to start designing for anything else?

In my personal experience I've cost my company $2M in engineering time by letting a customer drive the requirements for us to design and qualify a solution that the customer ended up not buying. Vans is smart to not put themselves in the same situation.

Otherwise you are perfectly free to design the firewall forward package for an alternative engine and perform all the of the testing to qualify it.
 
Totally agree with the frustration of not having an engine that can run on ethanol free mogas. Hopefully the IO-390 will eventually have some sort of approved modification that will allow E-0 mogas without any major hit on performance. I’ve got a Champ that uses $3.30 mogas, the local airport is at $5.40 for AVGas.....it’s not that big of a deal at 4 gallons an hr but it will be at 8 gallons an hr....
 
Totally agree with the frustration of not having an engine that can run on ethanol free mogas. Hopefully the IO-390 will eventually have some sort of approved modification that will allow E-0 mogas without any major hit on performance. I’ve got a Champ that uses $3.30 mogas, the local airport is at $5.40 for AVGas.....it’s not that big of a deal at 4 gallons an hr but it will be at 8 gallons an hr....

Well you got it good, the difference between mo & AV where I am is more like $4. That’s why I am interested in the 520T. That engine is heavier than the 520is by 14kg and VANS asked ULpower not to put a520is in an RV14 because it was to light and prop was further forward. But the 520T is heavier and a similar price to the IO - 390 importantly it costs $30 an hour less to feed where I live. The engine is about 3 inches longer so you would need a new cowling and the prop would be 3 inches further forward I assume. Don’t know how critical that is.

People say you can engineer the fuel system so that you can use mogas on Lycoming IO-390 and I assume that’s true but I would rather the engine manufacturer did that work as ULpower have done
 
People say you can engineer the fuel system so that you can use mogas on Lycoming IO-390 and I assume that’s true but I would rather the engine manufacturer did that work as ULpower have done

The fuel system issue has been solved. But the 390 is a high compression engine and that is what ultimately prevents you from using premium auto fuel.
 
What about ordering a lower compression IO-390, something that can run on 92 octane E-0 mogas? I’m curious how much HP you would lose going to 8:1. I’m assuming cruise speed would be the same.....hopefully there will be movement on this front as 100LL gets more expensive and less available.
 
What about ordering a lower compression IO-390, something that can run on 92 octane E-0 mogas? I’m curious how much HP you would lose going to 8:1. I’m assuming cruise speed would be the same.....hopefully there will be movement on this front as 100LL gets more expensive and less available.

Not sure the compression ratio is the big issue as The ULpower 520is uses 8.7:1 and seems to be able to use mogas?
 
UL Power's spec's all call for mogas in the 95-98 octane range. That isn't what most people consider mogas, because it isn't readily available.
I have ran 91 zero ethanol 95% of the time in my ULis engine since about 10hr and now have 565hr on it. The factory minimum is 93 octane. Spec for head temp is maximum 390f. My head temps never exceed 260f on the hotest day in a continuous climb never having to tip nose over for head or oil temperature. Spark plug threads are coated with thermal conductive paste. I believe keeping the head and plug temps lower allow the use of 91 octane with no issues.
 
I have ran 91 zero ethanol 95% of the time in my ULis engine since about 10hr and now have 565hr on it. The factory minimum is 93 octane. Spec for head temp is maximum 390f. My head temps never exceed 260f on the hotest day in a continuous climb never having to tip nose over for head or oil temperature. Spark plug threads are coated with thermal conductive paste. I believe keeping the head and plug temps lower allow the use of 91 octane with no issues.

Interesting, do you have the engine installed in a vans aircraft?
 
Remember that Europe and the US use different measurement methods for octane, so take that into account when talking about pump gas ratings and requirements published by motor manufacturers.

EU 95 = US 91
EU 98 = US 93
(Roughly)
 
According to the UL power website the fuel requirement for a 520 is : MOGAS with min. 97 octane rating or AVGAS (98 Oct = 90MON = 94 AKI)

In Europe, the octane rating on the pump is simply the RON figure. America, by contrast, uses the average of the RON and the MON figures, called the AKI (anti-knock index). Thus, 97 octane “super unleaded” in Britain is roughly equivalent to 91 octane premium in the United States.
 
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Just a thought and I don't have a horse in this race. I build and own extremely high horsepower and very fast drag race cars. I have over 100 pounds of lead ballast on the nose of my car alone. Without it I would literally tear the wheelie bars off at launch. Is it not possible to bolt 40 pounds of lead ballast to the front of the UL engine, or wherever else it's needed? I'm building a -12 and the Rotax has been through several changes from the original design. Every change has added weight. So, it is possible to go up or down in weight within reason. These are Experimental Aircraft and in my experience throughout life, nothing is impossible. There is a way! As for my -12, it is on hold pending the upcoming LSA rule changes. If I were a betting man, I would say a new and more powerful engine (Lycoming), higher gross weight and a single lever control will be engineered into the -12. I never planned on using the Rotax anyway. I've been considering many different options and the UL350is is at the top of my list. I'm years away from that decision anyway. I hope more kit manufacturers and more builders use the UL engines. I hope more people build Van's aircraft with UL Power! Experimental is the reason I am building a Van's aircraft. I will probably get torn apart because of this post. I'm here to learn and share. If I were building a -14 or -8 I would absolutely be looking at UL Power. I have a very capable engineering team that will help me also. Is the original question/post impossible and unsafe? Absolutely not! Just my .02
 
Agreeed

I’m, 75 years old and have built three experimentals with a lifetime in Ag aviation. My choice is also the UL engine for my -12 but there’s a new problem.

In the past, it was ignition redundancy seen to with two mags (all my life)...now, it’s electrical power, or the engine stops. I’ve been assured by my friend, the importer, Ray Lawrence, that the alternator is more than capable of providing the minimum needed volts. I still want redundancy, so I’m adding a second independent battery.

The UL engine is really a state-of-the-art newbie and that’s where I’m headed as well.

Regards,
 
Lots of folks running Mogas in Lycs and you can retrofit EFI and EI easily on a 390. We're done a number of them now.

I guess they retard the ignition at high manifold pressures by a few degrees when using Mogas on the IO-390?
Do you have some rough numbers you can share?

Malte
 
We generally recommend no more than 16 deg of total timing on AV engines burning 91 mogas at MAP above 26 inches. You can slowly advance timing as MAP decreases.

This will cause a slight loss of power over 100LL and the full 20 deg of timing near sea level but generally cruise power and fuel flows below about 24 inches MAP will be unaffected.

As always, the usual cautions apply- high CHTs and IATs increase the likelihood of deonation.
 
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This will cause a slight loss of power over 100LL and the full 20 deg of timing near sea level but generally cruise power and fuel flows below about 24 inches MAP will be unaffected.

Thanks for the info!

So you had also no problems running the IO-390 LOP with Mogas?

Malte
 
Thanks for the info!

So you had also no problems running the IO-390 LOP with Mogas?

Malte

I'm not aware of any 390s routinely burning 91 mogas but several AV 360s and a number of PV engines with higher than stock compression ratios. I think Toobuilder has been burning 87 octane in his PV 540 Rocket for a while now with our EFI and EI.

Pretty well any engine can run on mogas if spark timing is properly managed and CHT/ IATs are kept at reasonable levels. There is nothing special about 390s. They have an extra 0.4 to 0.9 CR over most other stock Lycomings but lots of folks are running 9 to 10 to 1 CRs in their Lycs or clones these days.

The key is to have programmable, variable timing to manage peak cylinder pressure losing the minimum amount of power at high MAP (TO power at sea level) and optimized timing at lower MAP in cruise to have best possible efficiency. You can't do that with fixed timing mags.
 
ASTM approval

UL power have got ASTM approval for their engines so hopefully more US kit manufacturers will consider them as a feasible option. Dual ECU built in, mogas out the box and now can be used on SLSA aircraft. I think the 520T could be a great engine for RV10 as well. Nice short video on UL power offerings in NA. I think anyone who provided kits of the quality of Vans but used UL power engines could find themselves eating some of vans market share.

https://youtu.be/VxSaI2K-bN0
 
I try to sum it up:
UL520T looks interesting!

Pros:
It is lighter than an IO-390
It has a Turbo
It has Electronic Fuel Injection and Ignition

Cons:
It is lighter than an IO-390
It has a Turbo

I have not calculated it in every detail but I think you could lose the advantage of lower weight to CG problems. You would not be able to put more luggage into your baggage area. You'd need to move the engine more forward. On my tail dragger this would result in a higher nose and more difficult taxying.
The Turbo allows to fly faster and higher. The RV-14 has a Vne of 200kts TAS. So you would maybe gain a few dozens knots of speed at high altitude and high power. But this also comes with higher fuel consumption. The turbo adds more complexity to the engine, which results in higher operating costs and higher risk of an engine failure.

The EFI is nice! But you can also use an SDS EFI on an IO-390. The SDS system allows you to tweak the engine as you wish. But it also requires some knowledge about engine tuning.

I don't know if the UL520T is that much better than an IO-390 - even if there's a FWF kit. It's also not cheaper than a Lycoming. I think I tend to an IO-390 Thunderbolt with SDS EFI/Ei. With some retarded ignition in low altitudes you should also be able to run with Mogas as outlined by Ross.

Malte
 
Not to put a damper on things but there have been a number of piston failures on earlier UL engines. Add a turbo and you'll add more heat to the piston crown.

Apparently, they went from cast to forged pistons at some point recently to address this issue. But I wonder how much time the new engines have on them?

Are the ECU calibrations zeroed in and proven over a long period? This is vitally important for longevity on an air cooled turbo engine.

Maybe best to wait a bit and see what field experience is like on the turbo models...
 
Just curious, why is everyone looking at the 220 hp turbo and not the normally aspirated 200 hp 520is. It weighs less than the 210hp io-390 so if you can solve the weight problem (without adding weight) wouldn’t this compensate for the 10hp deficit?
 
Just curious, why is everyone looking at the 220 hp turbo and not the normally aspirated 200 hp 520is. It weighs less than the 210hp io-390 so if you can solve the weight problem (without adding weight) wouldn’t this compensate for the 10hp deficit?

Most folks considering this engine choice would figure it an advantage to maintain those 220hp (with the turbo) up to cruising altitudes. The normally aspirated engine choice would have the 200hp power at sea level, & hp output would diminish with density altitude, just like the 390.
 
Most folks considering this engine choice would figure it an advantage to maintain those 220hp (with the turbo) up to cruising altitudes. The normally aspirated engine choice would have the 200hp power at sea level, & hp output would diminish with density altitude, just like the 390.

Also the UL 520 nun-Turbo has peak performance at 3300 rpm. You'd need to find a prop that is able to run at those high speeds. Most props from Hartzell or MT go only up to 2700 or 2800 rpm.
 
What he said. The UL 520 non-turbo models are around 175hp at 2700rpm. I'm sure 175hp in a RV14 would still outperform a 172, but not really what was intended.
 
Ok, all valid points on turbos….I’m trying to compare the 200hp UL 520 non-turbo to the 210hp IO-390 non-turbo that weighs 100 lbs more. If you can solve the CG issue of a lighter engine without having to add weight won’t it be a wash with the lighter engine (with 10 less hp)? Sounds like the 3300rpm may be the key issue that kicks the UL engine out of the pool (unless there is a prop out there that can take 3300rpm and 200hp).
 
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Not to put a damper on things but there have been a number of piston failures on earlier UL engines. Add a turbo and you'll add more heat to the piston crown.

Apparently, they went from cast to forged pistons at some point recently to address this issue. But I wonder how much time the new engines have on them?

Are the ECU calibrations zeroed in and proven over a long period? This is vitally important for longevity on an air cooled turbo engine.

Maybe best to wait a bit and see what field experience is like on the turbo models...

Yes great point, i have read about that as well. Hopefully the forged pistons will solve the problem but its certainly a concern, they don't have the same pedigree of the Lycomosaur for sure.

I wonder how many engines they actually have installed at present. I think the dark aero may increase their installed base significantly as it is design around the 520is and those guys have got quite a lot of pre orders for that plane. It could be ULpower breakout implementation
 
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