6 WORST & 6 BEST Light Sport Aircraft Engines

We cover the 6 worst and 6 best LSA engines, and what makes them good or bad.
Updated spreadsheet with the relevant engine information can be viewed here:
jmp.sh/5oSAi6UC
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Image credits:
-Poo emoji by Google (github.com/googlefonts/noto-e...) under license Apache-2.0 (www.apache.org/licenses/LICEN...) - no changes made to image
-O-200 photo by FlugKerl2 (Wikipedia - commons.wikimedia.org/wiki/Us...) under license CC BY-SA 3.0 (creativecommons.org/licenses/...) - no changes made to image
-Rotax 914 photo by Herr-K (Wikipedia - de.wikipedia.org/wiki/Benutze...) under license GNU Free Documentation License, version 1.2 (commons.wikimedia.org/wiki/Co...) - no changes made to image
-Jabiru 3300 photo by FlugKerl2 (Wikipedia - commons.wikimedia.org/wiki/Us...) under license CC BY-SA 3.0 (creativecommons.org/licenses/...) - no change made to image
-UL350iS photo by FlugKerl2 (Wikipedia - commons.wikimedia.org/wiki/Us...) under license CC BY-SA 3.0 (creativecommons.org/licenses/...) - no change made to image
-AeroVee 2180 photo by FlugKerl2 (Wikipedia - commons.wikimedia.org/wiki/Us...) under license CC BY-SA 3.0 (creativecommons.org/licenses/...) - no change made to image
-Rotax 912ULS photo by Greg Goebel (Wikipedia/flickr - www.flickr.com/people/3746737...) under license CC BY-SA 2.0 (creativecommons.org/licenses/...) - no change made to image
-Rotax 912UL photo by Robert Frola (Wikipedia/flickr - www.flickr.com/photos/robertf...) under license GNU Free Documentation License, version 1.2 (commons.wikimedia.org/wiki/Co... - no change made to image)
-Rotax 915iS photo by Matti Blume (Wikipedia - commons.wikimedia.org/wiki/Us...) under license CC BY-SA 4.0 (creativecommons.org/licenses/...) - no change made to image

[@LetsGoAviate]

I have updated the spreadsheet to fix some inaccuracies like engine pricing and weight and I also added two Aeromomentum engines due to popular demand. Link in video description.

[@RulgertGhostalker]

Add the HKS 700E for Lighter Sport .... that's the way i would go on a budget. ( but i can't find engine weight or cost figures ) seems like a Very Light engine, with Two Different Gear Ratio Options...Smooth Boxer Twin, And No Hot Cylinders hiding behind cooler ones. that would be like Super Powers, with the 2.58:1 reduction on a Rutan Quikie.

[@RulgertGhostalker]

Wow....that little HKS 700E could pull a Quickie Q2 !!! Plus It Is Way Lighter than the VW engine they normally put in them...a little faster, or better range, with the HKS 700E....it would be like sheding a bag of concrete.

[@RulgertGhostalker]

quickies have a ground effect lump you have to learn when landing them.... but no big deal, once you got the hang of it.

[@RulgertGhostalker]

i can't afford it right now though....sure looks nice, check out those kit pictures.

[@RulgertGhostalker]

i can't find anything on the stock Q2 propeller diameter .... just that the Q2s have been known to scrape their props on landing, ( because of the flex in the forward wings ) i would probably try Epoxy and 4" Mono-Directional Carbon fiber tape, ( one stripe along the bottoms of the front wings, to add tensile ), and run the same diameter in a high aspect ratio 3-blade on the HKS 700E 2.58 to 1 reduction. just guessing the stock propeller is about 1.3 Meter Diameter, where the same, in a 3-blade on the 2.58 to 1, would give 88% Efficiency, which is better than stock at the same dia.

[@charleswesley9907]

The VW from Steve Bennett powered my KR2 just fine . It produced 74 hp at take off , 65 continuous and never let me down in over 800 hrs. It was cheap to work on and there were many parts sources . And at 2.9 gallons per hour burn was great for economy .

[@crono331]

The VW derivatives in the 80hp class are ok for a single seater, but too marginal for two. There are several VW powered aircrafts in my hangar, and they almost never fly with a pax, unless a really light one and in winter. props suitable for 3300rpm are less efficient and that adds to the already marginal performance. Looking at these airplanes operate, they look more like 65hp airplanes, not 80. "powered my x airplane just fine" doesnt mean much, if for instance you operate from 4000ft rways at sea level and in mild temperatures. the same airplane will become a death trap in the mountains in summer.

[@cramersclassics]

Well done! The quest for reliable and affordable power has always been the Achilles heel of sport aviation. Back in 1993 I installed an NSI EA81 100 HP Subaru in my Kitfox 4. Still flying today with 650 hours. Its works well but certainly heavier than a Rotax 912. Any auto parts store can usually get me what I need which is cheap and fun. Too bad nobody does the Subaru these days in kits.

[@its4michael]

Almost 500 hrs on my Jabiru 3300. Nothing but oil changes and compressions averaging 79. Fuel efficiency is excellent. You're right about weight for LSA but only for the lowest weight airframes (but if your flying those you might as well pick up your motor at Harbor Freight). It has had a lot of attention from the manufacturer improving it's durability departing from the stories that haunted it years ago; a story that ALL engines have! The key is good fuel, good oil and staying in operational limits.

[@Crosshair84]

A tried and true story. "Lets push the envelope." *Later* "TOO FAR!!! TOO FAR!!! Dial it back." *Later* "Okay, that works nicely."

[@corindikevcorindikev]

The Rotax 912 ULS is a very good engine but the weight of 149 lbs quoted is for the engine only with some components. The dry weight of the engine only is 131.6 lbs.When you add the liquid coolant & radiator, water pump, oil cooler, pipework, exhaust system, etc the weight increases to 194lbs. Then the airbox is an extra 3lbs which is required to get the 100HP (5 minutes only). So the installed weight ready to fly is close to 200lbs. The Jabiru 3300 weight is 180lbs and that is ready to fly with only an oil cooler to add to the weight. Plus it is rated at 120HP and can be run at peak power continuously.

[@crono331]

Thats a load of bull re the weight. And the jab 3300 sucks. All people i know who had one scrapped it.

[@corindikevcorindikev]

@@crono331 You are entitled to your opinion no matter how uninformed it may be. The data I provided came from Zenith who manufacture aircraft and install 912ULS engines in their airframes. There are over 7000 3300A engines flying around the world. I own one and it has never missed a beat. The 4 cylinder version operates in many flying schools and most reach the 2000 hour TBO. They are rarely fully overhauled as the cost to replace with a new one is less than the overhaul plus the new engine is the latest generation and comes with all the upgrades.

[@crono331]

@@corindikevcorindikev the data i rely on comes from ME. I have two airplanes powered by the 912. Plus, i recently bought a second hand one, and the guy who delivered it to me took it off the trunk of his car with >one< hand. the weights quoted by Rotax are correct, 56kg including the oil reservoir,. and a set of radiators, hoses, fluids and an exhaust will add around 10kg or less. Those who talk about 80, 90, or 100kg installations are lying or used components salvaged by diesel locomotives. I have considered buying a Jab 430 and gave up after ALL the people i asked about the engine told me they had problems ranging from bad cylinders to a broken crankshaft, through a long list of defects and problems some of which ended up in emergency landings. add to that the very limited choice for props and the endless work necessary to baffle the engine to cool it properly, which is also one of the reason of the frequent problems.

[@aviatrix2]

You'll want to update your information. The Rotax 912 series advertises their weights without exhaust, radiator, muffler, etc. Also, Jabiru's cost about 50% more than you were advertising. Jabiru advertises their weights ready to fly, minus the prop. In the end, the 912 series weighs very close to a Jabiru 3300.

[@crono331]

No it doesnt but even if it did, the 912 works, the jab doesn't. Its a unreliable engine with tons of problems.

[@OleDiaBole]

Friend of mine has Slepcev Storch STOL. He swaped normaly used Rotax 912 with Yamaha motorcycle engine. You could change gears mid air to reduce engine RPM. Result was 150hp instead of 90hp, and compared to Rotax, consumption dropped from 18 to 8 liters.

[@eugeneoreilly9356]

200 hp from one liter engine beats anything from the aero engine makers.Only drawback is high rpm.

[@Rockingruvin]

Change gears midair … that’s awesome.

[@Rockingruvin]

@Tommy but if you change gears, rpm comes down and all you need is enough RPM to stay high in the torque curve for max power. Just like cruising on the highway. Well, similar…

[@user-ej9jq2zf1y]

Oh my goodness changing gears in flight that is awesome!

[@PDZ1122]

It's BS . @@Rockingruvin

[@ZenCH750]

all great reviews, however one little side note, the ULPower weights listed are ready to run weights, fully ready to run, with oils in, wiring harness and ECU included, exhaust system mounted and installed, filters, pumps and baffling ( which is also supplied with engine!) . Rest are dry weights listed by manufacturers without oils, water, exhaust, radiators etc installed. I have done plenty Rotax and ULPower 350 series installs and they are similar weights installed but 130 hp EFI vs 100 hp Carburetted. And then pricing is also wrong. Most of these need substantial extra costs for items not supplied with the engine and not ready to run out the box ( ULPower engines are ready to run out the box, Jab out the box but all the liquid cooled engines do not include additional items needed to be able to actually start the engine, that do NOT come with the engine - and some dont include exhaust systems either!). So alot of hidden costs and weights not included.

[@ldmax]

The advertised power of UL Power engines is at 3300rpm - too high to efficiently operate as direct drive engines. However, a gear reduction drive is not included. So, you either have to add a gearbox - which increases cost and weight...or you have to operate the engine as a direct drive at a lower rpm - which reduces power output. In both of these scenarios, the UL Power engine becomes considerably less favorable compared to other options.

[@willcall9431]

Gearboxes aren’t the answer. The only benefit of a gear box is smaller displacement running at a higher rpm. Plus you have another maintenance point and potential failure point.

[@ExceptionallyCleverUsername]

​@@willcall9431a reduction gear is going to let you turn a larger, more efficient prop at a lower rpm. That's a pretty big benefit, and it's why all large those big radials, Merlins, etc. had reduction gears. Generally on light aircraft Lycoming and Continental have decided the weight, cost and mechanical complexity aren't worth it. If you have a 3300 rpm engine without gearing you can of course run a smaller prop at higher rpm, but it'll be less efficient. Generally accelerating a larger mass of air less is more efficient than accelerating a smaller mass to a higher speed.

[@kevinswanson3910]

The 4th gen jabiru 2200 engine is the better buy now with the changes no more valve adjustments and torqued heads with 2000 hour rebuild, is now 85 hp

[@wasitbeu2]

Go the Jabiru! Love them, used to build them at the factory!

[@ITSFUNZ]

Liking the AeroMomentum AM13 ! Water cooled FADEC engine here ! 170 lbs 100, 112, and 126 HP options ! All new parts custom built ! $9,995 100HP $13,995 126HP Just my thoughts!

[@LetsGoAviate]

Yeah AeroMementum looks great (on paper at least)!

[@patriciasmith4800]

Give me a Suzuki engine any day

[@Mike-tt8wi]

I like that option also, just waiting to see if they develop complete FWF packages- not an area I’m interested in beta testing.

[@arnaldoborghi2194]

Loved the video simple and direct to the Point, the only thing I would change, is that you keep half screen as you talk about the engines so we could Look the engines as you talk about them, this would avoid pausing the video so many times and misss what you are saying.

[@LetsGoAviate]

Thanks, good idea! I'll see how I can do something to that effect in the next one.

[@edwinkania5286]

I like this list it shows that I have been doing my homework and I agree with your analysis. Great Video.

[@brianmuhlingBUM]

Well done, very valuable information.

[@colibri67]

Seven out of fifteen aircraft at our airfield have the Rotax 912ULS. Of the remaining eight aircraft, no two of them have engines similar to each other. So your first place choice is good.

[@mathieusan]

you forgot to mention the total time between overhaul, and average cost of an overhaul. This way, one can compare an operating cost per hour (with or without fuel, too)

[@officialvalencia9074]

Thank you for these videos ive only rebuilt cars and motorcyles but im trying to get into this so o appreciate ths info

[@LevPicaresco]

Good and informative video, thanks.

[@QUICHENOTTES]

Thank you for this very interesting study and for your advice. Joël from France

[@alastairnewman1233]

Lekker vid mate. Very useful. Thanks very much for making it.

[@notpoliticallycorrect]

Excellent video!

[@chuckcawthon3370]

Great comparisons, well done.

[@LetsGoAviate]

Thanks!

[@Marchetti7]

great video, thanks

[@DamianMealor]

I work at Jabiru aircrafts (Bundaberg Qld OZ). cool video.

[@LetsGoAviate]

Thanks

[@TENpilot]

Very good review 👍🏻 👍🏻

[@toohip1959]

First time I have come across your channel. Well done.

[@LetsGoAviate]

Thanks and welcome!

[@caesarillion]

Years ago I built a KR2 kit with a 36 hp VW engine for reliability. Because of the power it was basically a one seater but it flew fine and was very low speed at landing. Top speed was 119mph and ceiling was may be 9500'. My total cost for the build was about $1800 but the year was 1976.

[@fercat2508]

The Jabiru 3300 is The Best, for me. Got a couple of those, one generation 1 and one Gen 3 . Very reliable, fair price, simpler installation than the rotax 912.

[@fercat2508]

More power, cheaper price.

[@LetsGoAviate]

A large chunk of my flying time is behind the Jabiru 2200, and have a few hours behind a 3300. I find opinions on them are very divisive, people either fully love them or fully hate them. I'm on the fence...

[@jonathanpersson1205]

The Jabiru’s arent reliable the through bolts stretch then you have an engine failure

[@urbansimoncic8623]

Where you can get jabiru 3300 for 12k? I think it is about 22k.

[@bennisvcat1340]

It was fixed many years ago regarding these bolts in Jabiru

[@billcuster]

I didn't see a mention of the 912is. Same HP as the 912ULS but far more fuel efficient, no carb tuning, and just a little bit more cost.

[@dc42duet3d]

And claimed 20% better fuel efficiency than the -ULS.

[@eggenfellner]

Just FYI, we weigh the same installed as an O200 and not generally any CG issues and a large amount of our aircraft are for light sport aircraft with over 900 in Zenith aircraft. With excellent performance, and low fuel burn, especially for STOL style aircraft. ❤ a bit heavy for things like a small kitfox or something of that nature though, good for the Viking 90. The Viking 90 is a great option too, almost everything similar to the 912, works wonderful for little pushers too. As some mentioned above, the UL power rating is also at an unattainable RPM. Just keep in mind most companies advertise things different than they actual are. This includes aircraft kits and their performance. We try to aim at honest weights and performance so the customer is never disappointed

[@LetsGoAviate]

Thanks for commenting and for the additional info. Good on you for advertising honest numbers, it goes a long way towards building that trust. Pity I haven't seen an Viking engines around in South Africa yet, would love to see them perform!

[@ManNomad]

I'm thinking the 90 in a 701 would work for me. Have to testily a few options over the next few years and determine my operational needs like if I have a runway, its length, etc.

[@BlueMax333]

very useful to see info on a spreadsheet

[@LetsGoAviate]

And just updated too 🙂

[@VK4JMP]

A Jabiru 3300 actually puts out 130Hp and weighs 176 lbs but it is easier to leave it certified as a 90kW (120HP) engine. The Jabiru 2200 actually puts out 88 HP but the specifications have not been changed. I have flown aircraft powered by both these engines and I have also flown aircraft powered by Rotax 912. The direct drive Jabiru engines are nicer to fly and they don't have that rattly reduction gearbox when taxiing with the Rotax engines. My choice is Jabiru 3300.

[@SM-nm1oc]

Aren’t they problematic with high temp issues ?

[@kennethsanders2937]

No

[@willcall9431]

I’m amazed at the output of the UL 350Is . I had it paired with a sensenich two blade adjustable prop and the Fadec was Amazing albeit on the rich side. Started up and idled with ease regardless of engine and outside temperature.

[@ldmax]

The advertised power output on the UL Power engines is at 3300 rpm. That is incredibly inefficient and loud without using a gear reduction drive - which is not included. Add in a gearbox and the price goes way up. Operate the engine as a direct drive at a lower rpm and power goes down considerably. The 350is becomes a 115hp engine at 2700 rpm.

[@willcall9431]

No engine is operated at rated power continuously for purposes of fuel efficiency. The UL isn’t noisy either . Sounds like you are unfamiliar with them.

[@carlosromero3165]

Thank you for the information provided! such a help!!. Do you have a spreadsheet with the information shared on the video? it would be very appreciated if you can share it!

[@LetsGoAviate]

Yes, take a look in the video description, there is a link to the spreadsheet

[@robopgenorth329]

One thing you did not mention when talking about Viking engines is that they are USED CAR engines salvaged from junk yards with unknown wear and tear or damage. Yes he dresses them up to look nice but they are used with unknown milage. Be careful they are not new engines!

[@weavera1970]

Very interesting. He unfortunately doesn’t even mention the Corvair, not sure why. In my opinion, the Corvair 2850cc is the best option for power/weight/cost/reliability. It outputs 112 HP, is about the same weight as an O-200 (but has more HP & a third the cost), is a direct drive 4 stroke, 6 cylinder horizontally opposed air cooled engine modified for aircraft use that you can buy complete or build yourself and save even more money!

[@LetsGoAviate]

Someone else also mentioned Corvair in a comment. It's not that popular in my opinion, but of course I could be wrong. And I though it was very heavy (on paper specs) but you know how that goes, true ready-to-fly weights not always readily available.

[@alexlo7708]

When you reduce power in exchange to reliablity, Lycoming goes on this way. The 3000 cc in automobile would easily go 200+ hp.

[@darrellcook8253]

If only Chevrolet anticipated the demand for aircraft conversion kits that the core was easily converted to. Now cores are becoming hard to find. Because Corvairs are cool.

[@jayterrill3252]

Corvair engines are junk! @@darrellcook8253

[@Flightstar]

Great presentation and selection. I think a good compromise would be a basic Rotax 912 with a low compression big bore kit. Doesn't add much weight, 107 hp and burn reg gas.

[@AustNRail]

The Jabiru 3300 as it delivers 120hp and its maintenance costs are much lower than Rotax.

[@renegadeflyer2]

Prop RPM should be point of considering. VW engines don't work well with long props. But with the right aircraft, it could be a very good engine and a reasonable priced engine

[@irishflyer6377]

Reliability is more important that power to weight or price. When you become a glider all of a sudden you would gladly pay the extra for a reliable engine, I know this and you will too if you fly enough hours.

[@LetsGoAviate]

I agree 100%. The problem is reliability is subjective. If I were to direct you to statistics showing Rotax (912 & 914) is the most reliable non-type certified engines people will be posting hate comments to me left and right (I've seen it on videos and forums), because if a person has flown a Continental for 2,000 trouble-free hours, they believe it's the most reliable. But in reality that's a single reference point on a statistics table. That is why I stated the criteria I'm basing this on and said I'm not looking at reliability. I wouldn't buy an engine based on only these criteria, but I just wanted to make a fun comparison video about cold hard stats available about these engines. If I'm to include reliability I'd be going off my own perception and I'd be spreading a non-factual opinion. I hope that makes sense.

[@Rockingruvin]

The aerovee can be assembled by the pilot if so desired in about 16 hours, and a turbo can be added for additional takeoff power and regaining some of the lost power at higher altitudes. I purchased the engine in kit form from someone giving up on their Sonex build, so I got it much cheaper than retail. I did have to buy the turbo modification from Sonex. If you build the engine/airframe yourself, you can get a repairman certificate for your plane and do all the maintenance, repairs, and even annual condition inspection. Lots of saving there, but you have to have some experience in working on engines and be good with building things.

[@b.chuchlucious5471]

What is the compression ratio on those Aerovee engines? A well built 2180 in a Bug should be north of 125hp. Is the c/r lower to help with reliability?

[@user-wx4up5yg3d]

An aircraft engine can/should only run at max.3200 rpm. At 125 hp you run at 5000 rpm and would need a reduction drive. You also would get cooling and reliability issues

[@frederickwoods5943]

@@b.chuchlucious5471 most aircraft engines produce a half horsepower per cubic inch. It makes them last longer and keeps CHT lower; the VW engine in-the-air has a horrid history, the Sonex crash at Oshkosh halted my progress on building one and a VW powered KR-2 crashed on final to the north end of the runway about a half mile from my house killing the pilot and his father-in-law. Love my VW's but won't try to fly with one.

[@brianschumaker5912]

Compression ratio can be set at 7:1, or 8:1.

[@michaelwall8747]

I have been looking at the Corvair engine. I would like your comments on it. Thx, Michael

[@richardneilsen5538]

I have been flying a Kolb MKIII with a valley reduction drive 2180cc VW for about 25 years. with careful trimming it weighs about 20 lbs more than a Rotax 912 at about $10,000 less producing about the same thrust.

[@kevinsellsit5584]

Interesting video. As a non aviator engine guru I would have liked to have more info like "opposed water cooled OHV 4 cyl fuel injected" etc...

[@LetsGoAviate]

Going into the different engine types could be fun, might be a topic for a future video focussing on 1 or 2 engines.

[@noeramirez4975]

Will be interesting include the comparison of the statistical data on how long they last before the engine overhauled. Many of them break a piston, a valve, etc.

[@LetsGoAviate]

That would be ideal. Not very easy to do though, as they are operated under different rules, some allowing owners to build and service them, which influences reliability. I also know some of these engines are extremely unlikely to run until TBO without prior failure.

[@ExceptionallyCleverUsername]

​@@LetsGoAviate"extremely unlikely to run until TBO without prior failure" never stopped anyone from buying a Bonanza, SR 22, or anything else with an IO or TIO 550.

[@theaeronaut-channel]

Very clear informative video, as usual. Among the 4-stroke, I am very interested in testing the MWfly. It has great characteristics, just not a history as long as Rotax. For the 2-stroke my heart is with the Italian engine Simonini Flying V2

[@LetsGoAviate]

Thanks. I'm aware of the Simonini but not the MWfly. Had a quick look online and they seem interesting, will need to check them out in more detail.

[@alexfink4227]

And we couldn't beat the shaking at low speeds.

[@brenthollady]

I fly a 202cc Simonini PPG, the engine produces plenty of power for me and is super reliable! I love my Simonini

[@williepierce5480]

You are exactly right

[@wf8058]

Enjoyed your video but would like you to do one on engine reliability. Thanks.

[@RulgertGhostalker]

the HKS 700E for Lighter Sport .... that's the way i would go on a budget. seems like a Very Light engine, with Two Different Gear Ratio Options...Smooth Boxer Twin, And No Hot Cylinders hiding behind cooler ones. that would be like Super Powers, with the 2.58:1 reduction on a Rutan Quikie.

[@iancormie9916]

Corvairs and Aeromentum (Suzuki) and Yamaha have loyal followings.

[@MrLeslloyd]

Did the opposed 4 and 6 cyl sidevalve engines (D motor) die out?Was there a fundamental problem exposed?they looked promising when they came out.

[@rogersjung3612]

Tanks !

[@oscarwindham6016]

I would like to hear your assessment of these engines without the cost issue. Just tell me which is the best engine, and I will worry about the cost.

[@daszieher]

DMotor?

[@redowlranchairfield5994]

Shocked that Aeromomentum didn't make the list somewhere!

[@maxcastiglia]

Great video! but please, where do you get your Jabiru 2200 at only $7000 !? It seems to me that brand new it sells for more than double that price.

[@LetsGoAviate]

Thanks! And yes even though I got that price on 2 seperate websites, it was way out of date and goes for much more now.

[@BlueMax333]

Aeromomentum used to claim that they use Suzuki engines. Now their website says, "We buy all brand new parts from OEM suppliers". Suzuki G engine was introduced in 1984 and went through many revisions. AM13 is based on the GEO-Suzuki G13BB which came about in Mach 1995. The G series engine went out of production long ago and was superseded by the J, K, M and R series. The "new" engine, claimed by some converters can not be from a Suzuki factory. Possibly, they are put together from spares produced by third party manufacturers. Having said that the G13BB had a good reputation. A person with mechanical skills should be able to put together an inexpensive DIY aircraft engine using conversion kits. Another company that has long been converting the Suzuki GEO engine is AirTrikes.

[@LetsGoAviate]

Good info, thanks!

[@scottwatrous]

Interesting list in that it tries to just look at the objective details. Of course always hard to compare things apples to apples and there are so many small factors that can make even a 'terrible' choice based on this chart a really good and sensible one all things considered. Volkswagen based engines are plentiful in the light airplane world for a reason even if they're a bit heavy for the power. And LSA manufacturers continue to stick with the Rotax as basically the only viable option despite the costs for a number of really good reasons as well.

[@LetsGoAviate]

Yes that's it exactly, it's an objective list. The only way to make an objective engine comparison on reliability is to use statistics. But besides the fact that statistics isn't always fully representative, and can be presented to confirm anyone's bias, it isn't going to change anyone's mind. I can (and have) shove statistics in anyone's face on the reliability of the Rotax, but the ones who believe they are not reliable will still believe that they are not, no matter what facts presented. It's almost fully subjective. It's pointless (in my opinion) to talk about reliability on the internet, unless the goal is to open a can of worms, which this video seemed to have achieved even though it completely avoided the reliability subject. 🤷‍♂️

[@andymunnings9109]

"Thank you for the information. We as customers and consumers need to know the truth when purchasing an airborne engine plant. Thank you for your honest experience due to usage of these systems." 👍

[@droge192]

Why place your comment into inverted commas? "Do you hope it will be quoted by generations to come?" 😄

[@BlueMax333]

AeroVee VW based engines are sold as kits only. There is also a AeroVee (turbo) 100 hp @ 3,400 rpm, 83.9 kg (185 lbs) less oil Kit $15,000 (includes intake & exhaust)

[@Ichibuns]

They require more maintenance than most, but parts are robust amd dirt cheap. They're amazing for the aircraft builder. Not so great for people that will be paying shop rates.

[@anthonyburke5656]

My criteria is different to yours, I consider: horse power, 4 stroke, EFI, water/fluid cooled, noise and a fail in any of those can disqualify

[@portnuefflyer]

With over 3000 trouble free hours of trouble free Rotax 912S time, I have no plans to change. And....., that was while following a fraction of the official Rotax maintenance procedures, just changing the oil every 50 hours. Automotive oil filters, taking off when the temps reach 85 degrees not their recommended 125, and so on.

[@LetsGoAviate]

Yeah and you're not alone, many have done thousands of trouble free hours behind a Rotax. They don't fail often, and my own findings are when they do it's often fuel related, being incorrect or improper fuel rigging.

[@portnuefflyer]

@@LetsGoAviate Yes, the many different causes of a so called "engine failure" in homebuilt aircraft are legend! Bad cooling system, funky fuel delivery, etc.. BTW: I also put 1300 trouble free hours on a Subaru EA-81 conversion , converted by the now defunct Stratus company. Belt reduction, mostly a stock engine. Heavy and harder to cowl (bigger) than the 912 were the only downsides. I only paid $5800.00 for it, all converted, back when I was a 912 skeptic and they were relatively new, now I am a 912 zealot!

[@timking2822]

A simplified analysis. If you value reliability, it might change the results. Just like if you do a lot of flying in high altitudes and mountainous terrain.

[@LetsGoAviate]

For sure, from person to person there would be factors and scenarios that would change the order

[@TheOwenMajor]

I'd like to see how you are able to rank engines by reliability. At least in the EA world, reliability is an almost entirely subjective opinion.

[@rescue270]

This is why I don't favor water cooling and FADEC. People are forgetting why airplane engines are air-cooled and have magneto ignitions and carburetors or mechanical fuel injection systems. Water cooling is one more point of failure and one more system to maintain. Electronic engine systems are dependent upon an electrical power source, so they will fail if the airplane's electrical system goes down. Backup batteries are yet another maintenance item to check on all the time. None of this complexity is required with magnetos and carburetors. Magnetos are fully self-contained, self-generating ignition systems that are completely separate from the battery and alternator. The alternator can explode and the battery fall out and the engine will keep running as if nothing happened. The FADEC people don't want you to know that...

[@philipritson8821]

What was the aircraft fitted with the Janiru 3300? I like it! Thanks.

[@LetsGoAviate]

That's the Bat Hawk

[@user-fx6lc4im2s]

I’d not touch Viking engines as a general rule. We’re putting one on a CH650 and let’s just say the customer service is reported as sub standard. Jabbies are a better option in my opinion.

[@raydreamer7566]

Please next time include the usable and most efficient RPM's that the motor can produce power. Peak horse power ( also in Kilowatts ) at what RPM and cruse HP ( KW ) at what RPMs these are very important details for aircraft performance.. Liked your video..

[@LetsGoAviate]

Thanks for the idea, will include more details in the next one.

[@Mianthadore]

As an Australian, I'll never touch anything with a Jabiru powerplant. They're notoriously unreliable, it feels like I hear about somebody performing a forced landing in their Jabiru once a fortnight here. It's gotten to the point where CASA had to investigate them. Their airframes are good, though. As long as you put a Rotax in them.

[@boydw1]

I'm not convinced the Rotax is much better. I know firsthand of a couple of 912uls that failed (both in planes I'd flown in, though thankfully not while I was flying in them). The few Jabiru's I know of have been problem free (seems the later gen Jabiru's are better - now up to gen 4). Even the first batch of 915is started shitting exhaust valves, and had to be upgraded.

[@jabflyer5159]

I fly the Jabiru 2200 in its own frame/cell/airplane SP470. Upgraded with the bigger cooling heads and bigger ducts inlet air. Also stronger startingmotor and valves pretty well adjusted to correct measures. It's A DREAM to fly and I fly it regularly overseas. Not a moment of uncomfortable feeling. Just cruising at 2800 rpm (Rotax 5000) a pleasure to fly and maintain. Sorry but every time a Rotax flies overhead I think abouth a coffee grinder. Why the reduction gears???

[@gmcjetpilot]

4:53 UL Power engines (ALL OF THEM) are notorious for making less power than advertised, using power numbers at 3200 RPM. Direct drive engine means Prop is way past ideal efficient RPM. Actual HP at a reasonable 2800 RPM is 20HP LESS....5:40 UL2600iS as the UL350iS lower HP than advertised, and ALL UL power engines eat pistons, rings and cylinders at one time. Fixed? Seal leaks, Customer support are problems. ROTAX prices don't include radiator & exhaust I recall.

[@ZeeCaptainRon]

unless you have real world evidence and experience, you cannot possible say "all" of any anything does any such thing. I immediately discount everything you say when you make a sweeping blanket statement like "ALL UL power engines eat pistons, rings and cylinders at one time" Try again please.

[@georgemcqueen6593]

@@ZeeCaptainRon You may want research it. Try UL Power Facebook page and other airplane forums. I just looked. There is a new picture of a cracked crankshaft behind the prop hub. UL Power engines did have piston cylinder issues in the past. Not sure if that has been corrected or what model engine it affected. However UL Pwr engines are made similarly, adding displacement of more cylinders. A common or universal complaint I read is advertised HP overrated. They do rate HP at 3200 rpm which is too fast for Prop. So 500 rpm slower, for 2700 rpm you can expect to make 15-20 HP less at lower RPM. Although not a LSA there is a RV7 with UL520 Power engine rated at 200 HP. In cruise speed is about 30-40 mph slower burning the same fuel as a180 HP Lyc powered RV7. If I had to pick an LSA engine it would be Rotax 912 or Continental O200. What the video says is high cost. True, but does not consider a used O200 can be bought and overhauled yourself (with help) for a fraction of the price of a new O200 at 2023 prices. Good luck with your project.

[@ZenCH750]

bollocks. The one test you refer to was only done at 2800 rpm vs 3300 rpm that is the listed max hp rpm. Also note that UL now lists HP at 3300 rpm and at 2800 rpm. On the 350is its 6 hp difference! On that test all other engines were ran at their listed RPM for peak HP, accept the UL engines. And your statement all ULPower engines eat pistons and cylinders is total BS as well.

[@gmcjetpilot]

​@@ZenCH750 *"one test you refer to was only done at 2800 rpm vs 3300 rpm that is the listed max hp rpm. Also note that UL now lists HP at 3300 rpm and at 2800 rpm”* *UL power has notorious complaint from owner from UL power's earlier smaller engines to present larger 6 cyl 520 of making LESS HP regardless of their charts.* Their new and improved engine makes rated HP at 2800 RPM? OK sure it does. It is also TURBO CHARGED? Right. They are getting this by pumping up MAP. I bet there are limits to making this HP, and fuel flow will be hilarious. Lycoming can operate at 100% power all day as long as temps are OK. Lets see how many are in service, total hours and ACTUAL PERFORMANCE. Then we can talk. I am waiting to see it eat Lycs in sactioned cross counter races. Aerobatics? Forget it, not approved by UL Power. Please give me a break. It is still a 320 CU-IN displacement. There is no magic to make HP,, and no replacement for displacement. They did not event new technology or some "modern engine" magic that makes more HP or has better specific fuel consumption. Do your research. Up to you. Are you even in the market for a $150K kit plane? Because UL Power and the prop it uses will be well north of $50K alone, not including the airframe, avionics, systems, wiring, upholstery, paint... *“On the 350is its 6 hp difference! On that test all other engines were ran at their listed RPM for peak HP, accept the UL engines. And your statement all ULPower engines eat pistons and cylinders is total BS as well.”* Where do you get “6 hp difference!” Ha ha !!!!. Where do you get that. Their RATED 200 HP at 3200 RPM is actual PER THEIR DATA is close to 180 HP. I still DO NOT BELIEVE IT. Why the one EAB kit plane I am most familure with is the RV Van’s series building my first in late 80’s. Flew my RV4, RV6 over 2400 hours. Now building RV7. So there are two RV’s with UL Power. They are slower, burn about the same fuel. Go calculate that. I know what I am talking about. NOTE: ARE THEY BAD ENGINES? NO BUT I WOULD SPEND MY MONEY AND DID ON LYCOMING. ANY HONEST PERSION WOULD ADMIT LYC IS HARD TO BEAT AND IS AS RELEVENT TODAY AS IT WAS 60 YEARS AGO. What you said is irrelevant. I won’t get into the early dubious initial service history. Which to be fair has reported to be fixed? I do know they put CAST PISTONS in their early UL520’s. CAST. They now have forged pistons. A recent post on UL Power Facebook group shows UL520 CRANK SHAFT CRACK near the prop hub. OUCH. Personally my opinion is this is a boutique experimental engine. I would not put my money in to and get an (I)O320 or (I)O360 and get a REAL HONEST 160 or 180 HP (or 200HP for the angle valve. IN MY OPINION... being an aviation professional for 38 years, mechanical engineer, designed certified large jets, fly them, built two RV's, followed all EAB kit/plans planes, ALL engines used in EAB's, life time EAA member, I ADVISE CAUTION WHEN USING ANY ENGINE WITH LITTLE HISTORY AND UNKNOWN SUPPORT. Small planes like the Zenair can’t handle higher HP or weight engines. However an RV7, RV8 is designed for and specifically for a Lycoming 180-200HP. For same price or buying you can get an engine with massive support. If operated at 55-75% power LOP (lean of peak) you will burn identical fuel and/or go faster than a UL Power RV7 or RV8 at any power setting. I have the receipts and data Prove me wrong. Nothing matters except direct observation of performance and service history. Lycoming has the Bona fides. UL Power? TBD.

[@tonylam9548]

You missed Corvair and Aero Momentum. Some of those engines in the list produce their HP at over 3000 RPM, which is not as suitable for a slower aircraft. Rotax are not only expensive, but they are also behind the times, some of the engines still lack fuel injection and they are snail slow at higher HP models.

[@ulbuilder]

I'm planning to install an Aero Momentum AM13 on my Fisher Dakota Hawk. 170lbs, available in 100, 112 and 126HP. Prices vary from $10k for the 100HP vertical engine to $15.5k for the 126HP low profile version. 2000Hr TBO, fuel injection, gear driven PSRU, 16valve 4 cylinder. The vertical engine would be more appropriate for a single place or tandem aircraft where the low profile works well for wide two seat side by side fuselages.

[@patriciasmith4800]

And where was D-Motor??

[@boydw1]

@@patriciasmith4800 Or more to the point, what happened to D-motor? Vapourware?

[@jandejong2430]

@@patriciasmith4800 Now supplies to OEM only the website says...

[@ZeeCaptainRon]

You can't say they are behind the times by not having FI on some engines, many builders like a choice of carb vs FI. Yeah, I know, silly to not go FI, but there you are. I recognize the point that some like zero electronics between the fuel and combustion like magneto spark and a carb.

[@Nerdvona]

Aeromomentum has one of the best conversions. Best part is also affordability.

[@michaelmartin2486]

What about the Yamaha Apex? the NA version sports 150hp and weighs about 180 lbs and can be had for $12-20k. The absolute best powerplant available. It was designed to live its life at high revs. So cruising around at 7500-8600 rpm is normal use. Yamaha themselves are researching the light sport market and testing the 2 cylinder Phazer engine on a rans S6

[@LetsGoAviate]

Not included because it would beat everything on the list 🤣 Seriously though, the only auto (or snowmobile) conversions I included are those engines sold as a converted engine by a specialist company, e.g. AeroVee and Viking. The Yamaha Apex is a snowmobile engine, so still needs to be converted. If there is a company doing it and selling them already converted, then my apologies, I'm not aware.

[@michaelmartin2486]

@@LetsGoAviate Edge performance makes turn key Yamaha conversions. Called the EPeX. Offering in 150hp, 200hp and a 300hp version. Complete ECU, wiring harness, gearbox and propeller combinations.

[@LetsGoAviate]

@@michaelmartin2486 Of course they do! Completely missed that. Thanks

[@djmstride]

I will ask, where would you put the Aero Momentum AM13, 100HP @ aprox.170lbs. in this lineup?

[@LetsGoAviate]

Probably first 🙂

[@anderslockner9650]

Have you checked the D engine 4 and 6 cylinder/ weight

[@Maingear81]

How cheap is it to overhaul a 912? Any reliability issues with the 912 (Kathryn's report)? I was lucky to fly behind the engine I wanted in the same airframe being built.

[@LetsGoAviate]

I don't know the exact cost to overhaul, but I know it's not cheap (compared to buying a new one). Reliability 100% depends who you ask. I try to stay away from the subject, but I have hours behind a Rotax, that and based on others who fly and service them, they are some of the most reliable light airplane engines.

[@K1LLA_KING_KONG]

I like the UL Power UL520iS with 200hp @ 108kgs (wet) which is 1.85hp / kg. Although for a 5.2 litre engine is not much power

[@martijnstam6186]

Because it's a long-stroke and the 520T does 220hp@2700rpm. They could easily rev the engine to 5000 but requires a gearbox and wears faster.

[@DWBurns]

I have a supercharged LQ4/LS2 making 890HP but with a different pulley we can do 1050HP at 2700 prop RPM. My son in law and I want to put it in a plane but I can’t find a kit in that power range. Do you know of any kits that will take that power? I hand built the engine, it is a beast.

[@LetsGoAviate]

That's a lot of power. What does it weigh? Mike Patey's Draco had something in the region of 700hp, being a turboprop of course. So my best guess is it will need to be a modified plane to accomodate that. But I'm not an expert in the area.

[@elliottdiedrich3068]

SW P51.

[@krissfemmpaws1029]

I would more or less agree with you, but will say what's best for one aircraft design and pilot/builder may not be best for another. Service parts availability may also play into the equation of what's best. On my drafting board is a design that will have good performance on 80 horsepower if you are geared to turn an 78 to 80 inch propeller anything less that 72 inch the design falls on it's face.

[@petroelb]

Viking sounds great on paper, but there are a lot of people who have had less than stellar experiences with the engine and the company.

[@TheOwenMajor]

Define "a lot". I've scavenged the forums pretty extensively, and only found a couple customers who were really unhappy, and in hearing what happened it seemed to be a two way street

[@chippyjohn1]

​@TheOwenMajor I found many, only looked into it after hearing Jan talk BS. Listen to what he says, it's just bs.

[@RulgertGhostalker]

a 2.1 Litter, air + oil cooled, Radial-3 Turbo ( with the planetary ring cam bearing support beefed up to make it also act as a 2:1 reduction ) bore: 99.5mm x stroke: 90mm x 3 cyl. = 2.1Litter = 5,080 RPM ( engine ), 2,540 RPM ( prop ) @ just 3,000 fpm Ave. piston speed. sadly, no one makes one yet.....but if someone did make a Modern Radial-3 Turbo like that, it would probably be the Lightest on the list, and put out around 180 HP

[@RickWB2009]

Book numbers are dangerous. If you look at the 914UL and 914is engine/gearbox weight 140ish. Add in the oil tank, coolant tank, radiator, hoses etc...the rotax option start pushing 170+ lbs. Rotax are great and perform in all applications. But they should be ;chosen for their other benefits, not a false weight advantage. Some of the other weights given in the video are more accurate installed weights.

[@anne-vn2gz]

Hi there, who can do maintenance on the Viking 90 in South Africa? Seriously considering this engine for my Beaujon Viewmaster.

[@LetsGoAviate]

For NTCA in South Africa, any AP (approved person) who has the inline engine AP status may legally maintain them. I know of 1, but there will be a few of them around, not too difficult to find out on the forums.

[@markbits1960]

What about the WW Flycorvair conversion?

[@LetsGoAviate]

Weighs about 230lbs...that's O-235 territory.

[@bradleydavies3225]

To add my 2 cents worth. I am one of the Jabiru ‘statistics’ having had a complete engine failure in flight due to a dropped valve. Good result with a clean off field landing. But in my opinion I will always mistrust them as a result.

[@onthemoney7237]

I have one good engine but I’m sure its to heavy for his numbers he trying to hit what is it 200 = 220

[@Captndarty]

I put 460 hours on my 915 in 18 months with zero issues. It’s taken me up to FL250. If you can afford a 200k+ airplane you should be able to afford the price of a 915. In my opinion everything else is subpar underpowered naturally aspirated junk.

[@dwaynemcallister7231]

I have a 914, would like to get a intercooler at some point.

[@SR-gz6ps]

Forgive my question what about sinonini 110 hp It s a 2 stroke ??

[@SonexLLC]

You have to consider all-up installation weight when analyzing these engines. For example, by the time you add coolant, radiators, oil tank and carb heat and propeller to the 80hp Rotax, you end-up with a total installation weight very similar to that of the AeroVee. A similar comparison can be made between the 100hp 912iS and the 100hp AeroVee Turbo -- approximately 200 lbs. firewall-forward. Therefore, your assertions about the AeroVee power-to-weight vs. 80hp Rotax power-to-weight really aren't fair. Also, there are plenty of LSA aircraft out there with max gross weights under 1320 lbs. which also have lower empty weights (our Sonex is a great example), in which a 200 lb. firewall-foward installation weight with 80hp works-out quite nicely.

[@JRSawyer]

Where do you place the AeroVee Turbo on the list?

[@LetsGoAviate]

The turbo ups the HP to 100, and adds I believe 25lbs. That puts the weight close to the O-200, same power, but much cheaper. I'd place it below the Jabiru 3300 at 9th or 10th on the list. For perspective, it's just heavier than the Jabiru 3300 and outputs 20 fewer horses (at sea level of course).

[@droge192]

$40k for the Continental O-200 is just ridiculous when you consider that (unlike the Rotax 915i) it is only 100hp ! I think this choice of engine by Cessna was what killed their C162 Skycatcher. They could have taken thousands off the excessive price tag by using a Rotax 912 variant, or even moreso with the fantastic 'bargaib' Jabiru 2200 80hp.

[@BlueMax333]

Jabiru 2200 is US$17,900 from Arion Aircraft LLC, the exclusive US Distributor of Jabiru Engines

[@MilitaryTalkGuy]

at 7k, the 2200 jabiru would have been worth a hard look. At 17k, it will never sell here in the US. Arion needs to rethink their pricing or just quit offering the 4 cylinder jabiru in the USA market.

[@djal1030]

have you looked at the Aeromomentum engines?

[@LetsGoAviate]

I have not, but many requests for it here in the comments

[@BigBoreAdventures]

I think you should have also looked at the Aeromomentum AR15 and the AR15T.

[@LetsGoAviate]

It does seem like they have expanded their lineup since I last checked them out. Looks good!

[@TheOwenMajor]

If anyone is looking at Aeromomentum, I would highly recommend they look through the forums first. My understanding is their expansive lineup and offered services comes at the detriment of them actually being able to deliver on said products. Not hating, but I feel a need to mention it because on paper Aeromomentum looks very attractive, until you see multiple stories from customers waiting more than a year for crucial parts.

[@chippyjohn1]

@@TheOwenMajor I think you are thinking of the company that sell Honda engines, their history is a nightmare.

[@TheOwenMajor]

@@chippyjohn1 Viking? I wouldn't say a nightmare, I do understand a number of customers of his old Engenfeller Suburu conversions lost money when he went bankrupt during the great recession, but I really haven't anything bad about the Viking era of with Honda conversions. I'll I recall seeing is that one very angry customer whose engine quit on his initial climb out, but if I recall correctly that person was messing around with the ECU improperly.

[@ronuyeyama4020]

I have heard first hand nightmares of the Honda conversion company.

[@michaelmagill189]

No one seems to recall that turbo's and adjustable props are verboten in lsa aircraft. 915is has both. There is the possibility that the new regs being touted will allow them and increase weight allowance, but until they become reality they are only speculation and those engines are not applicable at any price or performance level

[@LetsGoAviate]

I'm pretty sure you can use a fixed (ground adjustable) prop on the 915. But if that's the case on the turbo, I wasn't aware. There's no such restriction on LSA's in South Africa.

[@chippyjohn1]

Many countries allow variable pitch props and turbos I don't know of any issue. The restriction is with the amount of controls/levers the pilot must operate, but with having a fadec engine, variable pitch and other devices are allowed because they do not add additional workload to the pilot.

[@randylavine3003]

What about millinium engines? Good price, weight and power! The Viking is very proven by automobile use and cost to maintain!

[@diGritz1]

I know the engine I want, but I haven't quite narrowed down the plane yet. It seems the r2800 shifts the cg a bit too far forward for most LS planes. "0_o"

[@z987k]

You have to de-rate the power of the UL engines to rpms you can actually spin a prop at. They rate them at 3300rpms, which would require a very short prop. Not applicable on most aircraft. Look at their power at 27-2800rpm and then compare.

[@LetsGoAviate]

Yeah that's unfortunate, been told that same thing in a few comments

[@z987k]

@@LetsGoAviate It's why there's been very low adoption of the engine. I cannot for the life of my think of why the engineers set it up for power at that rpm unless they thought their customers were idiots.

[@LetsGoAviate]

@@z987k It certainly doesn't build trust

[@dentech987]

Didn't mention anything about Verner radial engines. I want one. On sale now $1000.00 off.

[@fifi23o5]

You forgot MVFly Spirit, 160 preferable. Not the cheapest, but the most modern, great P/w ratio...

[@virtualcarrierwing3429]

Interesting, but where did you get the price on the Jabiru 2200 at $7000 US and the 3300 at $11500. That’s not even close as you can double those prices

[@LetsGoAviate]

2 different sites, one was ppgparamotor dot com (yeah I see where I've gone wrong). But check the pinned comment, I've fixed the pricing.

[@thespeedofchillax]

why no hirth engines included, like the 3203 or 3503? they are used on many elsa planes especially these days and seem to have positive feedback currently anyways ...

[@LetsGoAviate]

Nothing against Hirth. Just didn't consider engines with power output lower than 80hp.

[@thespeedofchillax]

@@LetsGoAviate ah, cool, was just curious. why the cutoff of 80hp, just personal preference...? i would've included down to 65 or 70 hp, just so those two hirth engines as well as the discontinued, yet still widely used and available rotax 582 blue head engine could be added to the comparison. i dont get why rotax stopped making the 582s, they seemed like such a popular engine or what not ... anyway, cheers man.

[@LetsGoAviate]

@@thespeedofchillax Yeah, personal preference. We had a 65hp Rotax 582 in our light sport, and it was dangerously underpowered. Might be prefectly fine on some other light sport aircraft though.

[@ConcreteBombDeep]

Is there name for when an aircraft produces more pounds of thrust then the aircraft weighs?

[@stanleybest8833]

Ron Ohler-teledyne 4a084