Man you guys deserve to be a million+ sub channel, these days UA-cam is filled with so much crap videos, viewers for awesome videos like this is scarce though. But you guys doing an awesome job. keep uploading!!!
Agreed!! There is a lot of garbage on YT, but there is also a lot of interesting, inspiring and educational content. However, you can’t fix stupid and you can’t force people to watch interesting content like this.
Hey Guys!! My name is Leandro and I speak from Brazil, I am passionate about aviation and it is part of my life, I always wanted to build my own plane. I've been dating the Lancair Legacy for a long time, but I was never convinced that I would have the necessary assistance to complete the mission. Your project is incredible, attention to every detail and apparently you are concerned with creating a true kit building experience. I am excited and believe that you will help me to fulfill my dream. Big hug.
Please utilize an augmenter exhaust system. Use the exhaust to create a low pressure system where the cooling air exits. It's free!!! Each exhaust puff pulls cooling air into the cowling. I made an exhaust system like this in my RV7 Project. Even on the hottest days, çylinder head temps were 300 degrees. It also work when you have a long taxi across a hot airport. You guys are doing such a wonderful job. Put your brain power to work thinking about an augmenter. I would be glad to tell you the simple method I used to size the components.
I'm blown away with the thought, effort, and choices being made. Awesome plane. I always wanted a 4 seater and room for golf clubs. My mind is changing. 😉 I pray the final price is within my range....under $125k.
Will you be doing any build “classes” or build assists? I’m highly interested as my mission profile would be sub 500m hops for real estate development site visits. I want something that can turn those from a 7hr drive to a 2.5hr flight for two people and some light luggage.
Looks good, guys! Perhaps a tip; The engine cooling depends largely on airflow and low pressure under it. Try to avoid the clutter under the engine, as it will make proper engine cooling hard. Ask the people at ULPower about inlet-to-outlet ratio and make sure you create a clean low pressure zone under the engine.
He said air flows OUT the bottom of the engine which will scavenge air from pressurized ram air above or even stagnant air in the plenum. So just adequate vents on the underside would prolly be OK.
Good looking build with regard to the fuel you said you can run either pump gas of race fuel how does the ECM adjust for the different octane ratings ? Second with the air box only having on opening at the front doesn’t the last cylinder receive the heat from the first two? That heated air coming from the heat box is now hot how is that supposed to keep the battery’s cool?
Guys, I've been following your incredible build from the start. Myself, I'm building a Velocity SE and I'm at a decision point as to the powerplant. I an seriously considering the UL520T as I live in Northern California and frequently venture over the Sierra Nevada Mountains. I would love to get a few minutes to hear your thoughts on the UL engine quality, components and installation. Thanks and keep on keepin' on!
Questions: 1. Why is the oil cooler on the opposite side of the oil filter? Space, hose strain relief, exhaust space? 2. Why is the cabin heat supply taken from the left airbox rather than right? Hose turn radius? Awesome workmanship and videos. Thanks
3:49- ignition harness securing, try a clickbond panpole bonded on the firewall. Back in my spacecraft days we used a ton of those for harnesses. Just make sure the adhesive is high temp so it doesn't debond(to do so, we'd stick a heat gun on it).
FUEL AND OIL SYSTEM: 1) Are the two primary fuel filters located in the cabin or in the front wheel well? 2) What provision have you made for mitigation of a fuel leak and/or fire on both the cool-side and hot-side, mount locations, of the fuel system (logically each of the connectors is potential points-of-failure)? 3) Does the oil-demister have a failure scenario where the bypass air could be contaminated with vent oil or oil mist and thereby could venting directly into the exhaust plenum possibly result in a oil fed fire? ENGINE UPGRADES: 4) Does your engine compartment have room for UL520iSA with its modified engine case, oil sump and oil pickup system including with the larger oil air breather oil which allows acrobatics such as vertical climbs, extended inverted flight and negative-G flight regiments and is this a feasible add on-you designed the airframe to handle this type of flying? If not, how difficult would it be to make room? 5a) Have you done a back-of-the-napkin design for feasibility, of the turbocharged (or is it a supercharged?) version of the UL520? 5b) If so would it fit within the existing engine compartment cross-section? 6) Is there room aft of the cabin to create a battery compartment to counter-balance these later engine mods including, if needed an engine bay stretch? AVIONICS: 7) Is there physical space as well as unused weight budget available in the avionics bay as well as the instrument panel? 8) What is the avionics weight budget? 9) The avionics bay seems quite cramped. Does it have an active cooling system? 10) What is the weight budget allocated to avionics and instruments? OXYGEN: 11) Since the cabin is unpressurized, is there space mount an oxygen system for the pilot and passenger for flying above 10,000 feet including FL180 through FL200 (I live west of the Rockies. Flying over terrain vs lots of canyon flying seems safer especially with your higher performance DA-1.)? CABIN HEAT: 12) What is the projected engineered-in ambient air temperature, altitude and airspeed that the cabin heat can compensate for? COLD WEATHER FLYING: 13a) I see no provisions for wing, control surface and prop de-icing, nor would I expect it, but icing aside, is the airframe suitable for cold weather flying (winter/arctic)? 13b) If yes, what are parameters for cold weather flying? 13c) Does the carbon fibre in the craft limit G-loads in cold weather conditions and if so, what are these design limits? OVER WATER FLIGHT: 14a) Does the aircraft have provisions for FAA or in my case DOT approved over-water flying? 14b) What are the over water flight imitations expected to be? 14c) If so, in a ditching over water, situation, what type of floatation equipment is or could be made available without compromising your design? OTHER EMERGENCIES: 15a) Does the aircraft have provisions for a crash activated emergency transponder? • BAILOUT - I believe initial flight testing, even for experimental and kit built prototypes, may require the test pilot have a parachute for a situation where the airframe breaks up at altitude. If not a Regulator requirement, I suspect most test pilots would make this a contractual requirement. 15b) Can the seats back padding and seat belt harness be modified to allow for a thin chute insert? 15c) I believe your design has the canopy hinging forward. I know this may not work in a flat spin with little air moving past the canopy but does your design have a provision to pop/eject the canopy in an emergency? WINGLETS: You have indicated that you are looking at adding winglet in a future design iteration. These would increase safety margins by lowering stall speed and improve landing handling characteristics, increase rates climb for a given unit of power and improve higher altitude flight characteristics. They can also increase fuel efficiency, increase range, increase in aircrafts full weight limits, provided the airframe and landing gear can maintain safety margins, and some designs integrate winglet tanks to further increase fuel load which further increases range. 16a)I know the development timeline is fluid, but saying flight testing is completed by late 2020 or early 2021 and kit production begins in early to mid 2021, where do winglets sit in the priorities list for Dark Aero future upgrades? 16b) Is it top of the list with 2022 being projected for winglet development?
components are 'caged' in case of catastrophic failure.. same logic as redundancy.. safety is number 1.. you'd be shaving pennies, not silver dollars, in terms of weight.. all housings are aluminum.
Looking great, fellas! Funny how, maybe at the outset, it would seem that the engine bay has loads of room for installation and then, in the end, there is just enough space for all the systems. If my understanding of the UL electrical system is correct, the engine will function with battery power (limited duration) or alternator power independently, or nominally (watching lots of NASA, Space X video lately) alternator maintaining battery-powering ECU. So, in essence, you have something more than a double redundancy with two batteries (and two ECUs?)depending on how they are wired into your bus (es). Firewall mounted oil cooler is one less mount to fail. Many oil coolers are hung off the cooling plenum in other installations which often results in mount failure.
6:00 шланги подходящие к теплообменнику на выпускном коллекторе не расплавятся от температуры выпускного коллектора? 6:00 hoses suitable for the heat exchanger on the exhaust manifold will not melt from the temperature of the exhaust manifold?
@darkaeroinc the Deltahalk engine coming next year seems a great option for your type of mission (speed and economy). Will it be possible to be mounted on the DarkAero in the future?
With the emphasis on aerodynamic smoothness, I didn't see any jack points. For gear swings, etc, will the completed airplane be on a foam pad cradle or some such? =PC=
Great Job! :) Some quick questions I had were, do you plan to make a 4 seat version, and secondly what all electronic safety systems will be in the Dark Aero 1. Can't wait to see one in the air.
I'm surprised at your decision to put the batteries in the engine compartment. I can't tell the battery type (AGM? LiPo?) but the temperature range at which batteries operate most efficiently, and have the longest life, is typically comfortable room temperature. Subjecting them to either radiated heat from the engine (or the exhaust manifold literally right next to it), or potentially icy cold blast during a winter's day from bleeding cooling air from the baffle is not ideal in either case. Was the battery location decision driven by weight? C/G?
Scott MacLean thank you for watching! The batteries are EarthX lithium and have an operating temperature range of -22F to 140F. Extreme temperatures were a concern we had with the placement in the engine compartment which is why we are implementing the battery cooling box. This will protect the batteries from radiant heat from the exhaust and other engine heat sources. We will show more of the cooling box in upcoming videos. The decision to place the batteries in the engine compartment was driven by weight, serviceability, and safety. Locating them in the cabin on the cold side of the firewall is not an option for safety reasons which would mean the only other choice would be somewhere in the back of the airplane. This would be a bad location for serviceability and the weight of the heavy gage wires running from the engine all the way to the back of the airplane ends up being several pounds. There is no ideal location for batteries on an airplane when all the factors get weighed out. The location we chose seemed to be the best balance for our design.
i want to see this baby completed and tasting the skie for the first time ♥️🙂 this is the most beautifull and the closest thing to a fighter plane it can get
Great work guys. It drives me nuts that the engine makers can’t put the air inlet in the right position and direction. The 180 deg bend is inefficient and ugly. Buts that’s my issue not yours. I’m so happy for you guys. Keep up the great work.
I'm sure there's a good reason, but why does the cabin heat come from the exhaust and not the oil cooler? Not enough temp? It seems like it'd be a nice way to eliminate the most common source of CO in the cabin.
Good question! The oil cooler is a good source of heat and we would like to use it for cabin heat as you suggested. We decided to keep the cabin heat and oil cooler separate since this is still a “test” aircraft. The bigger UL engines tend to pump a lot of heat into the oil system so we wanted to make the oil cooling easy to adjust if we find out it’s not cooling adequately. By keeping the cabin heat separate it means we are only messing with one system at a time during testing. Once we get everything dialed in and collect more data we can work towards integrating the oil cooling and cabin heat. There’s good incentive to integrate the systems because it means shaving a few pounds of weight and reducing part count
It's all sensible and tidy, but for reliability wouldn't it be preferable to have one battery and one set of ignition coils on each side? That way a problem in one area would be less likely to take out all electrical power or all ignition.
Awesome! Ads an A&P, I have a concern with the cylinder cooling there doesn’t seem to be an easy way to pull spark plugs or do a compression test. Does this engine not need the plugs ever changed or the compression tested?
I was researching that engine, which seems to me to have a lot going for it, but it gave rise to two questions: 1. How do you know you'll get the performance you expect at higher altitudes with a NA engine? , and 2. Would a 4 cylinder engine with a turbo give similar power to weight, without losing engine performance at higher levels? Thanks!
What’re you guys looking at cost-wise for this engine set up the way you have it? You know, including all the extra sensors and system backups that don’t come with it as standard from factory. Can’t wait to fly one of these when they’re available. Great looking bird!
What's the calculated cooling drag? I've red a few docs and it seems to me that water cooling (although heavier) is able to give much less drag with properly designed radiators/heat exchangers. But, aircooling is adhering to the KISS moto, so i guess that's that
Riley, love the videos and the content. Love your down to earth explanations. The only suggestion I would like to make is please get remote mike. Your audio level is up/down and sometimes difficult to hear. Looking forward to see this bird fly!!
Jim Dorn thank you for watching and for the feedback! We are excited to fly! Agreed that the audio got quiet in a few parts. We will add that to the list for continuous improvement. Cheers!
@@DarkAeroInc Thanks. I really don't want to come across as complaining. I'm not at all. I just know that you guys have a great drive to get it done with quality.
Question? Why the separate diodes and voltage regulator instead of following automotive practice and put everything inside the alternator. Some older autos put the regulator outside, it is about the size of a pack of smokes.The cabin heat tap off, is it enough for northern states and Canada. I know it is likely good enough for Calif. many southern designers had underestimate the heat requirement. I froze enough times in leaky 172 to know. At least this UL engine is the right RPM instead of 3000+ But UL, like Rotax, have not done the industry much favor by lowering cost.
Automotive alternators with separate regulator are regulating the field current; the alternator output rectification is done by diodes mounted directly in the alternator. He said that this regulator converts the AC to DC, which would be strange unless it is an actively controlled rectifier used with a permanent magnet alternator. Indeed the UL Power specs for the UL520iS include "Integrated permanent magnet AC generator, external rectifier-regulator"... so this is not like a traditional automotive installation. UL (or UL's alternator supplier) may have chosen to keep that active electronic controller (which is essentially a typical 3-phase inverter used only in generator mode) off of the hot and vibrating engine.
Really clean! I have to ask though. I've been watching a few other videos involving Lancair 360s (which, to me, seem like the spiritual ancestors to the DA1) and a really common issue with them is engine cooling. For example, many can't do a full-power climb without cooking the cylinders. They seem to have significantly more inlet and outlet area, unless there are going to be additional cutouts in the lower cowling that haven't been shown yet. Is this a concern? Is the UL Power engine more thermally efficient, or are you relying on more speed and a better plenum design to overcome the thermal issues? Thanks! Looking forward to the future videos.
The cylinder head temps don’t seem to be an issue on most UL engine installs because they have such large cooling fins on the cylinder heads. We were more concerned about oil cooling which is why we installed a large oil cooler with a dedicated duct system. Cooling is almost always an area that requires refinement on homebuilt aircraft so we tried to make everything easy to modify.
@@DarkAeroInc Thanks for the reply. I was discussing this with an A&P friend of mine who mentioned that a lot of cooling problems with the IO-360s also stem from the fact that even with perfect cooling, they tend to run hotter than one might expect due to the fin area problems. If you can get it to run nicely, I'm very excited for the major performance gains to be had from smaller cooling inlet area. Also excited to hear about the nose gear actuator redesign. I admit I was pretty skeptical of a stepper motor based system, since steppers tend to be heavy and lack torque relative to something like a brushless motor. I think the linear actuator idea is excellent and I'm looking forward to seeing it in action!
Thank you! The air box needs to be removed to get at the spark plugs which is maybe a 5-minute task. Nothing too crazy. Overall the setup is really easy to work on.
@@DarkAeroInc I think people are seeing the many rivets and assuming that it will not be possible to open the air boxes. I assume that once they are complete (which they presumably were long ago, now) they will lift off... although I don't know how, given that is wired and plumbed through them. Did this come up in a later video?
I would have expected to see wire supports closer to the plugs and cylinder temp sensors to keep wire vibrations from damaging the connection at the plug boot or top of temp sensor.
Tom Busey the fuel system is designed to prevent the filter from getting restricted. There is a large area pre-filter upstream of the fuel pumps to screen out initial debris. The main filter sits downstream of the fuel pumps and has a large internal surface area to catch debris without clogging. The fuel filter is changed on a 200 hour service interval to keep things running cleanly.
Oil cooler is thermostat controlled, meaning there will be flight regimes when the oil doesn’t flow through the cooler. That means no heat in the cabin. Which is why they use a heat muff on the exhaust system. The motor is running you got heat.
Considering this is a low wing airframe, how is the header tank fuel level maintained? I bet the Dark Aero One's fuel system is more interesting than most. I'm very curious.
The fuel sump/header tank sits at the base of the wing, and it is gravity fed from the wings. Fuel from the sump is pulled to the engine by a fuel pump. Fuel from the sump is pulled through an absorbent bladder (Holley Hydramat) that sits inside the sump, which helps to further prevent fuel starvation. You can see more of this setup in this video we posted here: ua-cam.com/video/zTQw7ITKdE0/v-deo.html
Great videos so far and a fascinating build. I'm curious about the fuel pump set up, are the pumps positive displacement? Running those in parallel like that and having centrifugal pumps would allow fuel to backflow in the opposite pump and I didn't see check valves in the setup. Just curious, you guys are intelligent and probably already thought of that.
Thanks for checking out the videos! The pumps are made by Walbro and each have a built in check valve which would prevent black flow. We actually just posted on our Instagram about a revision change to our pump set up and a similar question was asked.
Great work, guy's! One question is are those fins on the tops (outside ends) the cylinders in need of cooling? or are they just oil return volume around the valve springs?
Preston, the outside portion of the cylinders is where the valve rockers sit and they are force lubricated with oil so technically this portion of they cylinder is oil cooled.
We go over all of the 3D printed parts on the DarkAero 1 in this video here: ua-cam.com/video/F4a-ZQoHnFM/v-deo.html. For the inlets on the engine the technique used was selective laser sintering.
Did you galvanically isolate the firewall from the carbon fiber in the firewall forward? Curious what was used for that. I love the way this is coming together.
We used titanium for the firewall heat shield material which has a galvanic potential very similar to carbon fiber so it was not necessary to isolate it.
Some beautiful workmanship. Suggest using SCAT over SKEET on your cooling - I have personally seen delam of the inner skin and it will obstruct your flow. Also silicon seal the front side of the oil cooler (you probably just have not gotten to this yet). Am subscribed and enjoy you build immensely!
Greg, it's designed to cruise at 8,000 ft, but ceiling is 20,000 ft. Builders will have the option to put an oxygen system in depending on their mission profile.
great install fellas! i might have missed this elsewhere but are there 1 or two alternators? also what is the planned battery backup time? (30 minutes or more)
Thanks for the question! In this current configuration, we are using a single alternator, but employing two 24.8AH batteries. The idea here being that if the alternator fails, you would run purely off the batteries for the rest of your flight until you were able to land the plane.
The way the fuel pumps are plumbed, one of them will have more flow restriction in the plumbing fittings and so will presumably flow less volume... the same pump, all of the time. Reverse the connections on one end, so that each pump has one right angle in the flow (on the inlet side of one and the outlet side of the other) and flow will be more balanced. This is a fluid analogy to a common situation in parallel battery wiring; it won't matter as much here, but why unnecessarily put one pump in a more stressed situation?
I see that in "How do we start this thing?" ua-cam.com/video/-_zEcFkdq6Y/v-deo.html the fuel pump arrangement has changed, using inlet and outlet manifolds which will have balanced flow. 👍 🙂
Hi guys nice work, I have so questions regarding your engine installation, how you gonna deal with event of a engine fire (AC 20-135) I dont see any stainless steel or titanium sheet between composite firewall and engine?
Hi Ricardo! I didn’t cover it in much detail in the video but it was mentioned at 9:10. We are going to install layer of ceramic insulation covered by 0.015” titanium to act as a fire barrier and heat shield.
Beautiful installation. 3 questions/comments.. I assume there will be a gascolator so you can check for water and debris. Where will the air filter be and will you have a control to bypass it? Finally, can you post a fuel system schematic? The Rotax 912iS fuel system recommends a bypass line with a restricted orifice that serves a number of purposes including helping eliminate vapor lock, you didn’t talk about that, but that might be more detailed than you wanted to discuss.
Thank you for watching and for the questions! There is a drain to check for water in the sump tank at the lowest point in the fuel system. The air filter is located in the big shiny can on top of the engine. There is no bypass for the air filter. The UL520iS has the orifice bypass line built into the fuel system.
Nice vid on the engine. Couple comments... - wish you had talked about the engine mount and whether considered softer than typ rubber mounts to decrease sound in cabin - also wish you had discussed weight of engine compared to IO-360 Lyc. - also source of oil mist separator, or was it custom? Thx, look fwd to more vids.
Hi Dana, thank you for the questions! We just used the standard 65/70 Shore A rubber mounts in our setup. The UL520iS would be about 50-70lbs lighter than an equivalent IO-360 installation. The oil separator is made by Anti Splat Aero LLC. I'll touch on these topics more in the follow up engine installation video to give some more detail!
Really interesting project! I was curious on the firewall material? It seems like it should be covered in stainless or something for fire protection. Based on everything I've seen, I'm sure you've thought about that already, just curious.
Thank you for watching! The firewall is protected with a heat shield made from titanium sheet backed by ceramic insulation. The heat shield was not installed during this video. See 9:10 in the video.
The EarthX batteries we're using are indeed Lithium Iron Phosphate. We are still looking into employing the turbo version of the UL engine down the road, but are going to get the normally aspirated version up in the air first. The firewall heat shield consists of 0.016” thick sheet of titanium with a layer of Fiberfrax ceramic insulation behind it.
@@DarkAeroInc you might be able to have the batteries on the other side of the firewall, maybe in a can with an emergency vent. Because lifepo doesn't really burn. Sort of a second stage fire compartment. The firewall isn't fully hermetic, is it? so maybe a battery box can easily vent into the engine bay. They don't produce any real flames iirc. Just gas/steam.
The majority of cooling air diffusion should occur upstream of your inlet for a huge reduction in cooling drag. Your systems installation is beautiful but a lot of that will change after first flight. The more effort you put into your initial build the more reluctant you will be to change it after test flight. Burt had great success with the opposite approach. Mike Melville and Dick Rutan built the first long ez prototype in 10 weeks. Then they refined the systems and details on subsequent builds.
Very tidy installation. The UL engine ought to last forever at its understressed 200 hp. I understand maximum efficiency to be in the design brief; yet I can’t help but imagine a turbocharger on a further development of the aircraft. As it sits though, it’s wonderful, good job.
Tiago, thank you for watching and the comment. No, the heat exchanger is housed around the exhaust - it does not enter into the exhaust stream. It does not restrict its flow.
DarkAero, Inc ahhh I see. I’m not sure why I thought it was actually inside of the exhaust header hahah. Thank you for the response! Love the videos. I’m working on some carbon fiber pieces myself and your videos have helped a lot with certain types of processing
Would love to build one! Guess I would need to learn to fly! Are there plans for a 4-place kit? Your parents are very proud of you guys! Keep up the great work and vids!
Thanks Aubrey! We are pretty focused on the DarkAero 1 at the moment. A four-place would be a logical next aircraft however. ;) One plane at a time. :)
That is for a fifth mount point in addition to the four mount points at the back of the engine. The nose gear mount is integrated into the engine mount so the added support at the front of the engine helps support the cantilevered nose gear by transferring part of the load up through the engine and into the engine mount hard points. It also helps reduce the amount of engine deflection relative to the cowling under certain loading conditions.
Hey guys love watching this come to life . Wouldn't you want two injectors for redundancy in the ignition/combustion area? I was just curious on the probability of failure in one of those since spark/ mags are doubled up with the redundancy for ignition. I know injectors can be pricey tho...
@@DarkAeroInc The same is true of a plug or coil failure. Ignition redundancy without fuel delivery redundancy is a leftover from the days of unreliable electrical components and carburetors that could not reasonably be arranged with redundancy, and seems to be just accepted in general aviation because no one is willing to pay for anything better.
Good question! The portion of the air boxes above the cylinder heads contains cool air that has not yet passed over cooling fins and picked up heat. This is where we will be bleeding air from to keep the batteries cool.
@@DarkAeroInc But that was an interesting point: during idle on the ground there will be no airflow though the boxes, and the air in the top boxes will heat up - that probably won't be an issue for the batteries (and might help in cold weather starts), but it might be worth monitoring.
When I flew C210 and also Britten Norman Islander BN2 that had an iO540 at 300 Hp. So for an extra 20 cubic inches over the UL power 520 with all that flash control systems I was getting an extra 50% power or 100 Hp more with a comparatively simple engine. Just seems like a low Hp for the displacement and FADAC.
An IO 540 weighs in at ~360 lbs, the UL520 is about 240. 50% more power for 50% more weight. How is displacement relevant? I'd be more interested in weight, frontal area, and fuel consumption.
@@fantabuloussnuffaluffagus displacement is revelant because the ul has all that volume to burn fuel and has excellent engine control systems but can’t make any power from the volume. The IO540 was a simple engine built by a simple mindset of big gives you more and more Cubic inches per Hp means a lighter loaded engine running easy, it’s a 60 yo engine and mindset. However for a modern engine perfectly controlled and a huge capacity to have such a low power rating was shocking. For all intents and purpose the engines are almost the same physical size as the central crank would be similar size as would cylinders of a similar capacity. The weight disparity is expected though. Modern materials and design means you can pare back all wasted metal.
The 520 is 5.2 liters which is about 320 cubic inches. An O-320/IO-320 will give you 160 HP. The 520 will give you 170 HP at the same RPM, and 200 HP at about 3200 RPM.
Again in this video ex. 2:17 Darkaero did not use any rubber grommets when leading cables thru holes, that must be an mistake, hence cables tend to grind on all sorts of edges leading to electrical failures.. It is common knowledge in the automotive business, allways use rubber when leading cables thru anything... And again at 2:48 the cables allready rub against the edge of the hole...
AeroGarage I look forward to their answer, cooling is tricky. Looks like forward fins will get aggressive impingement cooling. These air cooled jugs can’t stay round. I expect the entire box to have static pressure, somewhat less over the first cyl but that’s what testing is for right. Maybe they did a CFD or copied off other installations?
AeroGarage the Venturi looking portion of geometry formed between the divergent inlet and the cylinder head exists only in a portion of the inlet, the rest of it is more open.
Man you guys deserve to be a million+ sub channel, these days UA-cam is filled with so much crap videos, viewers for awesome videos like this is scarce though. But you guys doing an awesome job. keep uploading!!!
Agreed!! There is a lot of garbage on YT, but there is also a lot of interesting, inspiring and educational content. However, you can’t fix stupid and you can’t force people to watch interesting content like this.
Hey Guys!! My name is Leandro and I speak from Brazil, I am passionate about aviation and it is part of my life, I always wanted to build my own plane. I've been dating the Lancair Legacy for a long time, but I was never convinced that I would have the necessary assistance to complete the mission. Your project is incredible, attention to every detail and apparently you are concerned with creating a true kit building experience. I am excited and believe that you will help me to fulfill my dream. Big hug.
Please utilize an augmenter exhaust system. Use the exhaust to create a low pressure system where the cooling air exits. It's free!!!
Each exhaust puff pulls cooling air into the cowling.
I made an exhaust system like this in my RV7 Project. Even on the hottest days, çylinder head temps were 300 degrees. It also work when you have a long taxi across a hot airport.
You guys are doing such a wonderful job.
Put your brain power to work thinking about an augmenter.
I would be glad to tell you the simple method I used to size the components.
Truly impressive and inspirational project. The quality and attention to detail is so nice to see, thank you for sharing this! Love your videos
The target specs for this plane are just incredible. Would love to build one someday!
That's impressive - You guys started this from scratch. Been following your work since the beginning. Amazing design follow through. .
That is a slick looking setup.
Eric Law thank you! We agree, but maybe we are biased. ;)
I'm blown away with the thought, effort, and choices being made. Awesome plane. I always wanted a 4 seater and room for golf clubs. My mind is changing. 😉 I pray the final price is within my range....under $125k.
Thank you! Maybe a 2-seater is really all you need! ;)
@@DarkAeroInc no room for clubs tho. I can but a Commanche for less also...so there is that.
Will you be doing any build “classes” or build assists? I’m highly interested as my mission profile would be sub 500m hops for real estate development site visits. I want something that can turn those from a 7hr drive to a 2.5hr flight for two people and some light luggage.
Really nice workmanship on that, great attention to detail. Such an exciting project
Looks good, guys! Perhaps a tip; The engine cooling depends largely on airflow and low pressure under it. Try to avoid the clutter under the engine, as it will make proper engine cooling hard. Ask the people at ULPower about inlet-to-outlet ratio and make sure you create a clean low pressure zone under the engine.
He said air flows OUT the bottom of the engine which will scavenge air from pressurized ram air above or even stagnant air in the plenum. So just adequate vents on the underside would prolly be OK.
Amazing work!!! Glad to see you're back in the shop!!!!
Thank you! It’s fun to be posting videos again!
@@DarkAeroInc what are the hinges around the firewall for?
@@anselmarcovici7940 they allow us to attach the cowlings to the fuselage.
Good looking build with regard to the fuel you said you can run either pump gas of race fuel how does the ECM adjust for the different octane ratings ? Second with the air box only having on opening at the front doesn’t the last cylinder receive the heat from the first two? That heated air coming from the heat box is now hot how is that supposed to keep the battery’s cool?
Love your workshop setup and videos. Dream place for design engineers
Nice clean installation.
Joseph Flood thank you! We have tried to keep things well organized. :)
Guys, I've been following your incredible build from the start. Myself, I'm building a Velocity SE and I'm at a decision point as to the powerplant. I an seriously considering the UL520T as I live in Northern California and frequently venture over the Sierra Nevada Mountains. I would love to get a few minutes to hear your thoughts on the UL engine quality, components and installation. Thanks and keep on keepin' on!
Questions: 1. Why is the oil cooler on the opposite side of the oil filter? Space, hose strain relief, exhaust space? 2. Why is the cabin heat supply taken from the left airbox rather than right? Hose turn radius? Awesome workmanship and videos. Thanks
3:49- ignition harness securing, try a clickbond panpole bonded on the firewall. Back in my spacecraft days we used a ton of those for harnesses. Just make sure the adhesive is high temp so it doesn't debond(to do so, we'd stick a heat gun on it).
Excellent that you are using an established modern powerplant with a new design. It is tough developing both at the same time.
Looks beautiful
Shawn Rhatigan thank you! :)
FUEL AND OIL SYSTEM:
1) Are the two primary fuel filters located in the cabin or in the front wheel well?
2) What provision have you made for mitigation of a fuel leak and/or fire on both the cool-side and hot-side, mount locations, of the fuel system (logically each of the connectors is potential points-of-failure)?
3) Does the oil-demister have a failure scenario where the bypass air could be contaminated with vent oil or oil mist and thereby could venting directly into the exhaust plenum possibly result in a oil fed fire?
ENGINE UPGRADES:
4) Does your engine compartment have room for UL520iSA with its modified engine case, oil sump and oil pickup system including with the larger oil air breather oil which allows acrobatics such as vertical climbs, extended inverted flight and negative-G flight regiments and is this a feasible add on-you designed the airframe to handle this type of flying? If not, how difficult would it be to make room?
5a) Have you done a back-of-the-napkin design for feasibility, of the turbocharged (or is it a supercharged?) version of the UL520?
5b) If so would it fit within the existing engine compartment cross-section?
6) Is there room aft of the cabin to create a battery compartment to counter-balance these later engine mods including, if needed an engine bay stretch?
AVIONICS:
7) Is there physical space as well as unused weight budget available in the avionics bay as well as the instrument panel?
8) What is the avionics weight budget?
9) The avionics bay seems quite cramped. Does it have an active cooling system?
10) What is the weight budget allocated to avionics and instruments?
OXYGEN:
11) Since the cabin is unpressurized, is there space mount an oxygen system for the pilot and passenger for flying above 10,000 feet including FL180 through FL200 (I live west of the Rockies. Flying over terrain vs lots of canyon flying seems safer especially with your higher performance DA-1.)?
CABIN HEAT:
12) What is the projected engineered-in ambient air temperature, altitude and airspeed that the cabin heat can compensate for?
COLD WEATHER FLYING:
13a) I see no provisions for wing, control surface and prop de-icing, nor would I expect it, but icing aside, is the airframe suitable for cold weather flying (winter/arctic)?
13b) If yes, what are parameters for cold weather flying?
13c) Does the carbon fibre in the craft limit G-loads in cold weather conditions and if so, what are these design limits?
OVER WATER FLIGHT:
14a) Does the aircraft have provisions for FAA or in my case DOT approved over-water flying?
14b) What are the over water flight imitations expected to be?
14c) If so, in a ditching over water, situation, what type of floatation equipment is or could be made available without compromising your design?
OTHER EMERGENCIES:
15a) Does the aircraft have provisions for a crash activated emergency transponder?
• BAILOUT
- I believe initial flight testing, even for experimental and kit built prototypes, may require the test pilot have a parachute for a situation where the airframe breaks up at altitude. If not a Regulator requirement, I suspect most test pilots would make this a contractual requirement.
15b) Can the seats back padding and seat belt harness be modified to allow for a thin chute insert?
15c) I believe your design has the canopy hinging forward. I know this may not work in a flat spin with little air moving past the canopy but does your design have a provision to pop/eject the canopy in an emergency?
WINGLETS:
You have indicated that you are looking at adding winglet in a future design iteration. These would increase safety margins by lowering stall speed and improve landing handling characteristics, increase rates climb for a given unit of power and improve higher altitude flight characteristics. They can also increase fuel efficiency, increase range, increase in aircrafts full weight limits, provided the airframe and landing gear can maintain safety margins, and some designs integrate winglet tanks to further increase fuel load which further increases range.
16a)I know the development timeline is fluid, but saying flight testing is completed by late 2020 or early 2021 and kit production begins in early to mid 2021, where do winglets sit in the priorities list for Dark Aero future upgrades?
16b) Is it top of the list with 2022 being projected for winglet development?
Awesome! May be cheesy but would like to see some lighting holes in the battery holders.
components are 'caged' in case of catastrophic failure.. same logic as redundancy.. safety is number 1.. you'd be shaving pennies, not silver dollars, in terms of weight.. all housings are aluminum.
Looking great, fellas! Funny how, maybe at the outset, it would seem that the engine bay has loads of room for installation and then, in the end, there is just enough space for all the systems.
If my understanding of the UL electrical system is correct, the engine will function with battery power (limited duration) or alternator power independently, or nominally (watching lots of NASA, Space X video lately) alternator maintaining battery-powering ECU. So, in essence, you have something more than a double redundancy with two batteries (and two ECUs?)depending on how they are wired into your bus (es).
Firewall mounted oil cooler is one less mount to fail. Many oil coolers are hung off the cooling plenum in other installations which often results in mount failure.
6:00 шланги подходящие к теплообменнику на выпускном коллекторе не расплавятся от температуры выпускного коллектора?
6:00 hoses suitable for the heat exchanger on the exhaust manifold will not melt from the temperature of the exhaust manifold?
Excellent craftsmanship & attention to detail! Well done!
Thank you Earl! Cheers!
This was labelled Part 1, and there were references to later parts... but I don't see any in the channel's video list. Was there ever a Part 2?
impressive engineering. can't wait to see it fly
Is the airframe designed to allow for future higher HP engines? I see that UL makes that engine up to 220hp.
@darkaeroinc the Deltahalk engine coming next year seems a great option for your type of mission (speed and economy). Will it be possible to be mounted on the DarkAero in the future?
Did you look at getting the cabin heat from the oil cooler... should be a little simpler to duct that into cabin.
How did you determine the size of the air inlets for the cylinder head cooling boxes?
With the emphasis on aerodynamic smoothness, I didn't see any jack points.
For gear swings, etc, will the completed airplane be on a foam pad cradle or some such? =PC=
Great Job! :) Some quick questions I had were, do you plan to make a 4 seat version, and secondly what all electronic safety systems will be in the Dark Aero 1. Can't wait to see one in the air.
I'm surprised at your decision to put the batteries in the engine compartment. I can't tell the battery type (AGM? LiPo?) but the temperature range at which batteries operate most efficiently, and have the longest life, is typically comfortable room temperature. Subjecting them to either radiated heat from the engine (or the exhaust manifold literally right next to it), or potentially icy cold blast during a winter's day from bleeding cooling air from the baffle is not ideal in either case.
Was the battery location decision driven by weight? C/G?
Scott MacLean thank you for watching! The batteries are EarthX lithium and have an operating temperature range of -22F to 140F. Extreme temperatures were a concern we had with the placement in the engine compartment which is why we are implementing the battery cooling box. This will protect the batteries from radiant heat from the exhaust and other engine heat sources. We will show more of the cooling box in upcoming videos. The decision to place the batteries in the engine compartment was driven by weight, serviceability, and safety. Locating them in the cabin on the cold side of the firewall is not an option for safety reasons which would mean the only other choice would be somewhere in the back of the airplane. This would be a bad location for serviceability and the weight of the heavy gage wires running from the engine all the way to the back of the airplane ends up being several pounds. There is no ideal location for batteries on an airplane when all the factors get weighed out. The location we chose seemed to be the best balance for our design.
That was my concern also, but the excellent answer fixed that concern.
i want to see this baby completed and tasting the skie for the first time ♥️🙂 this is the most beautifull and the closest thing to a fighter plane it can get
My ovations to use UL520is in your plane guys! Wise choice which will make all us safer while having fun flying!
Great work guys.
It drives me nuts that the engine makers can’t put the air inlet in the right position and direction. The 180 deg bend is inefficient and ugly. Buts that’s my issue not yours.
I’m so happy for you guys. Keep up the great work.
Great progress! Any thoughts or plans on integrating a ballistic parachute?
I'm sure there's a good reason, but why does the cabin heat come from the exhaust and not the oil cooler? Not enough temp? It seems like it'd be a nice way to eliminate the most common source of CO in the cabin.
Good question! The oil cooler is a good source of heat and we would like to use it for cabin heat as you suggested. We decided to keep the cabin heat and oil cooler separate since this is still a “test” aircraft. The bigger UL engines tend to pump a lot of heat into the oil system so we wanted to make the oil cooling easy to adjust if we find out it’s not cooling adequately. By keeping the cabin heat separate it means we are only messing with one system at a time during testing. Once we get everything dialed in and collect more data we can work towards integrating the oil cooling and cabin heat. There’s good incentive to integrate the systems because it means shaving a few pounds of weight and reducing part count
Hi! What do you think of switching to UL Power 520 turbo normalised version?
It's all sensible and tidy, but for reliability wouldn't it be preferable to have one battery and one set of ignition coils on each side? That way a problem in one area would be less likely to take out all electrical power or all ignition.
Awesome! Ads an A&P, I have a concern with the cylinder cooling there doesn’t seem to be an easy way to pull spark plugs or do a compression test. Does this engine not need the plugs ever changed or the compression tested?
By the way, did you consider this new UL520T (turbo charged) engine?
Very clean installation and explanation.
Thank you and thanks for watching!
Clean professional instal
I was researching that engine, which seems to me to have a lot going for it, but it gave rise to two questions:
1. How do you know you'll get the performance you expect at higher altitudes with a NA engine? , and
2. Would a 4 cylinder engine with a turbo give similar power to weight, without losing engine performance at higher levels? Thanks!
Now that I've been looking, I'm having a hard time finding a 4 cylinder with turbo that isn't nearly double the weight for similar power...
What’re you guys looking at cost-wise for this engine set up the way you have it? You know, including all the extra sensors and system backups that don’t come with it as standard from factory. Can’t wait to fly one of these when they’re available. Great looking bird!
What's the calculated cooling drag? I've red a few docs and it seems to me that water cooling (although heavier) is able to give much less drag with properly designed radiators/heat exchangers. But, aircooling is adhering to the KISS moto, so i guess that's that
I don't know if ye do or not but do ye have a parachute for the plane?
Riley, love the videos and the content. Love your down to earth explanations. The only suggestion I would like to make is please get remote mike. Your audio level is up/down and sometimes difficult to hear. Looking forward to see this bird fly!!
Jim Dorn thank you for watching and for the feedback! We are excited to fly! Agreed that the audio got quiet in a few parts. We will add that to the list for continuous improvement. Cheers!
@@DarkAeroInc Thanks. I really don't want to come across as complaining. I'm not at all. I just know that you guys have a great drive to get it done with quality.
after so long i see you come online ♥️🙂
Is there room under there to install the UL520 Turbo?
is there a redundant electronic distributors?
Hey guys, you are doing a wonderful job.
What’s the plan for the intake air? Will it be scooped up from the from two engine cooling inlets?
Question? Why the separate diodes and voltage regulator instead of following automotive practice and put everything inside the alternator. Some older autos put the regulator outside, it is about the size of a pack of smokes.The cabin heat tap off, is it enough for northern states and Canada. I know it is likely good enough for Calif. many southern designers had underestimate the heat requirement. I froze enough times in leaky 172 to know. At least this UL engine is the right RPM instead of 3000+ But UL, like Rotax, have not done the industry much favor by lowering cost.
Automotive alternators with separate regulator are regulating the field current; the alternator output rectification is done by diodes mounted directly in the alternator. He said that this regulator converts the AC to DC, which would be strange unless it is an actively controlled rectifier used with a permanent magnet alternator. Indeed the UL Power specs for the UL520iS include "Integrated permanent magnet AC generator, external rectifier-regulator"... so this is not like a traditional automotive installation. UL (or UL's alternator supplier) may have chosen to keep that active electronic controller (which is essentially a typical 3-phase inverter used only in generator mode) off of the hot and vibrating engine.
Are you gonna use a constant speed prop?
Jan we will use a constant speed prop. We will have more information on the prop selection in upcoming videos!
Did you spin the spinner off line to ensure its balance?
That's a beautiful engine ancillary layout. Any plans for EGT thermocouples?
Really clean! I have to ask though. I've been watching a few other videos involving Lancair 360s (which, to me, seem like the spiritual ancestors to the DA1) and a really common issue with them is engine cooling. For example, many can't do a full-power climb without cooking the cylinders. They seem to have significantly more inlet and outlet area, unless there are going to be additional cutouts in the lower cowling that haven't been shown yet. Is this a concern? Is the UL Power engine more thermally efficient, or are you relying on more speed and a better plenum design to overcome the thermal issues? Thanks! Looking forward to the future videos.
The cylinder head temps don’t seem to be an issue on most UL engine installs because they have such large cooling fins on the cylinder heads. We were more concerned about oil cooling which is why we installed a large oil cooler with a dedicated duct system. Cooling is almost always an area that requires refinement on homebuilt aircraft so we tried to make everything easy to modify.
@@DarkAeroInc Thanks for the reply. I was discussing this with an A&P friend of mine who mentioned that a lot of cooling problems with the IO-360s also stem from the fact that even with perfect cooling, they tend to run hotter than one might expect due to the fin area problems. If you can get it to run nicely, I'm very excited for the major performance gains to be had from smaller cooling inlet area. Also excited to hear about the nose gear actuator redesign. I admit I was pretty skeptical of a stepper motor based system, since steppers tend to be heavy and lack torque relative to something like a brushless motor. I think the linear actuator idea is excellent and I'm looking forward to seeing it in action!
Any consideration to the Jet-A fueled internal combustion DeltaHawk engine ?
What does that weigh and will it fit in the same space as the UL520iS?
Great looking install. How easy is it to remove spark plugs with that air box?
Thank you! The air box needs to be removed to get at the spark plugs which is maybe a 5-minute task. Nothing too crazy. Overall the setup is really easy to work on.
@@DarkAeroInc I think people are seeing the many rivets and assuming that it will not be possible to open the air boxes. I assume that once they are complete (which they presumably were long ago, now) they will lift off... although I don't know how, given that is wired and plumbed through them.
Did this come up in a later video?
I would have expected to see wire supports closer to the plugs and cylinder temp sensors to keep wire vibrations from damaging the connection at the plug boot or top of temp sensor.
What happens if the fuel filter gets plugged? Is that a possibility?
Tom Busey the fuel system is designed to prevent the filter from getting restricted. There is a large area pre-filter upstream of the fuel pumps to screen out initial debris. The main filter sits downstream of the fuel pumps and has a large internal surface area to catch debris without clogging. The fuel filter is changed on a 200 hour service interval to keep things running cleanly.
Why dont you use the wasteheat of the Oilcooler for cabin heating? Placement would be perfect and you reduce weight and the risk of CO in the Cokcpit.
Oil cooler is thermostat controlled, meaning there will be flight regimes when the oil doesn’t flow through the cooler. That means no heat in the cabin. Which is why they use a heat muff on the exhaust system. The motor is running you got heat.
@@oldschoolmotorsickle Ah, thank you :)
Considering this is a low wing airframe, how is the header tank fuel level maintained? I bet the Dark Aero One's fuel system is more interesting than most. I'm very curious.
The fuel sump/header tank sits at the base of the wing, and it is gravity fed from the wings. Fuel from the sump is pulled to the engine by a fuel pump. Fuel from the sump is pulled through an absorbent bladder (Holley Hydramat) that sits inside the sump, which helps to further prevent fuel starvation. You can see more of this setup in this video we posted here: ua-cam.com/video/zTQw7ITKdE0/v-deo.html
@@DarkAeroInc Thank you. Don't know how I missed this other video but it's excellent.
Clean
Jackson Hawker thank you! We have tried to keep the engine compartment layout orderly. :)
Great videos so far and a fascinating build. I'm curious about the fuel pump set up, are the pumps positive displacement? Running those in parallel like that and having centrifugal pumps would allow fuel to backflow in the opposite pump and I didn't see check valves in the setup. Just curious, you guys are intelligent and probably already thought of that.
Thanks for checking out the videos! The pumps are made by Walbro and each have a built in check valve which would prevent black flow. We actually just posted on our Instagram about a revision change to our pump set up and a similar question was asked.
Looks really good!
Great work, guy's! One question is are those fins on the tops (outside ends) the cylinders in need of cooling? or are they just oil return volume around the valve springs?
Preston, the outside portion of the cylinders is where the valve rockers sit and they are force lubricated with oil so technically this portion of they cylinder is oil cooled.
Great stuff! Would you mind sharing what material and printing method you are using for all the inlets?
We go over all of the 3D printed parts on the DarkAero 1 in this video here: ua-cam.com/video/F4a-ZQoHnFM/v-deo.html. For the inlets on the engine the technique used was selective laser sintering.
@@DarkAeroInc Thank you very much!
Did you galvanically isolate the firewall from the carbon fiber in the firewall forward? Curious what was used for that. I love the way this is coming together.
We used titanium for the firewall heat shield material which has a galvanic potential very similar to carbon fiber so it was not necessary to isolate it.
DarkAero, Inc badass! Titanium wasn’t cheap! Keep it up!
Do the fuel pumps each have their own check valves in series with each pump to prevent re circulation if one pump goes out?
Hi Bennett! The pumps each have a check valve at their outlet which prevents recirculating. Thank you for watching!
@@DarkAeroInc Dope! Thanks and keep up the great work!
Nate Mullins in a long EZ did not seem to have too good of luck with this engine. How will yours be different?
Some beautiful workmanship. Suggest using SCAT over SKEET on your cooling - I have personally seen delam of the inner skin and it will obstruct your flow. Also silicon seal the front side of the oil cooler (you probably just have not gotten to this yet). Am subscribed and enjoy you build immensely!
Do you fellas have any comments on the UL520iST (Turbo) ?
What flight level for cruise flight are you expecting? Oxygen system?
Greg, it's designed to cruise at 8,000 ft, but ceiling is 20,000 ft. Builders will have the option to put an oxygen system in depending on their mission profile.
great install fellas!
i might have missed this elsewhere but are there 1 or two alternators?
also what is the planned battery backup time? (30 minutes or more)
Thanks for the question! In this current configuration, we are using a single alternator, but employing two 24.8AH batteries. The idea here being that if the alternator fails, you would run purely off the batteries for the rest of your flight until you were able to land the plane.
The way the fuel pumps are plumbed, one of them will have more flow restriction in the plumbing fittings and so will presumably flow less volume... the same pump, all of the time. Reverse the connections on one end, so that each pump has one right angle in the flow (on the inlet side of one and the outlet side of the other) and flow will be more balanced. This is a fluid analogy to a common situation in parallel battery wiring; it won't matter as much here, but why unnecessarily put one pump in a more stressed situation?
I see that in "How do we start this thing?" ua-cam.com/video/-_zEcFkdq6Y/v-deo.html the fuel pump arrangement has changed, using inlet and outlet manifolds which will have balanced flow. 👍 🙂
Hi guys nice work, I have so questions regarding your engine installation, how you gonna deal with event of a engine fire (AC 20-135) I dont see any stainless steel or titanium sheet between composite firewall and engine?
Hi Ricardo! I didn’t cover it in much detail in the video but it was mentioned at 9:10. We are going to install layer of ceramic insulation covered by 0.015” titanium to act as a fire barrier and heat shield.
Awesome! What's the material used on the 3D printed parts?
They were printed using SLS with PA-12
clean and sleek design, naca inlet for oil cooler is an option
Beautiful installation. 3 questions/comments.. I assume there will be a gascolator so you can check for water and debris. Where will the air filter be and will you have a control to bypass it? Finally, can you post a fuel system schematic? The Rotax 912iS fuel system recommends a bypass line with a restricted orifice that serves a number of purposes including helping eliminate vapor lock, you didn’t talk about that, but that might be more detailed than you wanted to discuss.
Thank you for watching and for the questions! There is a drain to check for water in the sump tank at the lowest point in the fuel system. The air filter is located in the big shiny can on top of the engine. There is no bypass for the air filter. The UL520iS has the orifice bypass line built into the fuel system.
Nice vid on the engine. Couple comments...
- wish you had talked about the engine mount and whether considered softer than typ rubber mounts to decrease sound in cabin
- also wish you had discussed weight of engine compared to IO-360 Lyc.
- also source of oil mist separator, or was it custom?
Thx, look fwd to more vids.
Hi Dana, thank you for the questions! We just used the standard 65/70 Shore A rubber mounts in our setup. The UL520iS would be about 50-70lbs lighter than an equivalent IO-360 installation. The oil separator is made by Anti Splat Aero LLC. I'll touch on these topics more in the follow up engine installation video to give some more detail!
Really interesting project! I was curious on the firewall material? It seems like it should be covered in stainless or something for fire protection. Based on everything I've seen, I'm sure you've thought about that already, just curious.
Thank you for watching! The firewall is protected with a heat shield made from titanium sheet backed by ceramic insulation. The heat shield was not installed during this video. See 9:10 in the video.
How about LiFePO batteries for weight? and will you use UL's turbo engine at some point?
how about metal foil and insulation on the firewall?
The EarthX batteries we're using are indeed Lithium Iron Phosphate. We are still looking into employing the turbo version of the UL engine down the road, but are going to get the normally aspirated version up in the air first. The firewall heat shield consists of 0.016” thick sheet of titanium with a layer of Fiberfrax ceramic insulation behind it.
@@DarkAeroInc Nice, just looked like carbon fiber.
@@DarkAeroInc you might be able to have the batteries on the other side of the firewall, maybe in a can with an emergency vent. Because lifepo doesn't really burn. Sort of a second stage fire compartment. The firewall isn't fully hermetic, is it? so maybe a battery box can easily vent into the engine bay. They don't produce any real flames iirc. Just gas/steam.
@@DanFrederiksen what was shown in the video was carbon fiber. The titanium and Fiberfrax still has to be installed.
Nice looking engine 👍🏻
The majority of cooling air diffusion should occur upstream of your inlet for a huge reduction in cooling drag. Your systems installation is beautiful but a lot of that will change after first flight. The more effort you put into your initial build the more reluctant you will be to change it after test flight. Burt had great success with the opposite approach. Mike Melville and Dick Rutan built the first long ez prototype in 10 weeks. Then they refined the systems and details on subsequent builds.
Is it possible to upgrade the batteries to racing li- ions to save alot of weight?
Limatech produces certified Lithium batteries for this case of use, safer than race's ones.
Very tidy installation.
The UL engine ought to last forever at its understressed 200 hp. I understand maximum efficiency to be in the design brief; yet I can’t help but imagine a turbocharger on a further development of the aircraft.
As it sits though, it’s wonderful, good job.
I think you will find that the airboxes crack unless you put in a couple of slip joints.
Does the heat exchanger for the cabin reduce exhaust gas flow?
Tiago, thank you for watching and the comment. No, the heat exchanger is housed around the exhaust - it does not enter into the exhaust stream. It does not restrict its flow.
DarkAero, Inc ahhh I see. I’m not sure why I thought it was actually inside of the exhaust header hahah. Thank you for the response! Love the videos. I’m working on some carbon fiber pieces myself and your videos have helped a lot with certain types of processing
Tiago, no problem! Glad to hear the videos are helpful. 🚀🤓
Would love to build one!
Guess I would need to learn to fly!
Are there plans for a 4-place kit?
Your parents are very proud of you guys!
Keep up the great work and vids!
Thanks Aubrey! We are pretty focused on the DarkAero 1 at the moment. A four-place would be a logical next aircraft however. ;) One plane at a time. :)
What's the rubber grommet on the bottom front of your engine for?
That is for a fifth mount point in addition to the four mount points at the back of the engine. The nose gear mount is integrated into the engine mount so the added support at the front of the engine helps support the cantilevered nose gear by transferring part of the load up through the engine and into the engine mount hard points. It also helps reduce the amount of engine deflection relative to the cowling under certain loading conditions.
Hey guys love watching this come to life . Wouldn't you want two injectors for redundancy in the ignition/combustion area? I was just curious on the probability of failure in one of those since spark/ mags are doubled up with the redundancy for ignition. I know injectors can be pricey tho...
Ben Ward the engine continues to run if an individual injector fails although you would notice some roughness.
@@DarkAeroInc The same is true of a plug or coil failure. Ignition redundancy without fuel delivery redundancy is a leftover from the days of unreliable electrical components and carburetors that could not reasonably be arranged with redundancy, and seems to be just accepted in general aviation because no one is willing to pay for anything better.
wait did he just say he is gonna bleed heated air from the cylinder head cooling box to cool the battery? wouldnt that heat up the batteries as well?
Good question! The portion of the air boxes above the cylinder heads contains cool air that has not yet passed over cooling fins and picked up heat. This is where we will be bleeding air from to keep the batteries cool.
@@DarkAeroInc But that was an interesting point: during idle on the ground there will be no airflow though the boxes, and the air in the top boxes will heat up - that probably won't be an issue for the batteries (and might help in cold weather starts), but it might be worth monitoring.
I might have missed it, but how much does the engine weigh
108kg
Can you fly inverted with this set up?
The DarkAero 1 is not intended for inverted (or aerobatic) flight.
When I flew C210 and also Britten Norman Islander BN2 that had an iO540 at 300 Hp. So for an extra 20 cubic inches over the UL power 520 with all that flash control systems I was getting an extra 50% power or 100 Hp more with a comparatively simple engine. Just seems like a low Hp for the displacement and FADAC.
An IO 540 weighs in at ~360 lbs, the UL520 is about 240. 50% more power for 50% more weight. How is displacement relevant? I'd be more interested in weight, frontal area, and fuel consumption.
@@fantabuloussnuffaluffagus displacement is revelant because the ul has all that volume to burn fuel and has excellent engine control systems but can’t make any power from the volume. The IO540 was a simple engine built by a simple mindset of big gives you more and more Cubic inches per Hp means a lighter loaded engine running easy, it’s a 60 yo engine and mindset. However for a modern engine perfectly controlled and a huge capacity to have such a low power rating was shocking. For all intents and purpose the engines are almost the same physical size as the central crank would be similar size as would cylinders of a similar capacity.
The weight disparity is expected though. Modern materials and design means you can pare back all wasted metal.
The 520 is 5.2 liters which is about 320 cubic inches. An O-320/IO-320 will give you 160 HP. The 520 will give you 170 HP at the same RPM, and 200 HP at about 3200 RPM.
It looks like the turbo version would not fit?
Francis, that is correct. The engine mount would need to be modified to extend the engine out away from the firewall to make room for the turbo.
Again in this video ex. 2:17 Darkaero did not use any rubber grommets when leading cables thru holes, that must be an mistake, hence cables tend to grind on all sorts of edges leading to electrical failures.. It is common knowledge in the automotive business, allways use rubber when leading cables thru anything... And again at 2:48 the cables allready rub against the edge of the hole...
Slick. That divergent duct on the plenum looks like it's creating a venturi over the first cylinder thoug. Is that an illusion ?
AeroGarage I look forward to their answer, cooling is tricky. Looks like forward fins will get aggressive impingement cooling. These air cooled jugs can’t stay round. I expect the entire box to have static pressure, somewhat less over the first cyl but that’s what testing is for right. Maybe they did a CFD or copied off other installations?
AeroGarage the Venturi looking portion of geometry formed between the divergent inlet and the cylinder head exists only in a portion of the inlet, the rest of it is more open.