Engine Options (4S)

[Mudofficer]

Not wanting to hijack a great thread that has already been started on the Javron Four Place Cub (4S)...But needing a place to get more educated feedback on potential engine options that have been discussed on this new experimental platform. I'll start with some eligible engines, and some apparent pros and Cons. I hope the experienced members of this forum can pick those apart and help critique what an ideal engine will become for this experimental kit. Hopefully feedback oriented towards the best in class of modern experimental engine options, and the balance between reliability and performance, weight and power. Not meant to be an argument over why an 0320 makes the best lightweight traditional cub since that is already off the table with a 44" wide fuselage... but I could be wrong...This plane is not yet in the air.

Is there a reason to change up the more traditional 0360 while planning to build in 2023?

UL Power 520T
Pros- Power, Turbo, EFI.
Cons- Short TBO, Does it make rated power?
Notes- Promising engine. Runs smooth and make use of modern improvements, however some hurdles to overcome according to current owners. Nate Mullins from myulpower says the engine must be run ROP and does not like 100LL. Cato props is convinced they do not make rated power. Has a loyal following and good communication from their engineering team, but who wants to go first?

AC Aero 409ci Bored and stroked O-360
Pros- Some members of this board seem to love them.
Cons- Cost vs Benefit? Small number in service.
Notes- Traditional style. Would like to hear more from those with this engine in a two place cub currently flying it...

AC Aero Gladiator (water cooled 390ci)
Pro- Further weight savings with more power. Low CHTs
Con- Expensive, few in service.
Notes- Water cooled cub anyone? Can be built with other O360 modifications such as e-mags, EFII, etc. Water cooling actually lightens the jugs and closes tolerances. Can a radiator be worked into a new wide cub cowl? Would this be a good option for a LOP engine with constant speed prop?
Price: $62k includes new cryo case. 15weeks order to delivery.

Higgs Diesel
Pros- JetA/Diesel. Best power to weight Ratio. Fill up on cheap off-road diesel.
Cons- I'll believe when I see it.
Notes- Still just a model and proof of concept it seems. Production possible end of 2023?

Continental Titan X370
Pro- Javron preferred option. Traditional engine, lightened up with in-house build by Jay; 215HP
Con- 12month lead time (Order early 2023, receive 2024?)
Notes- Some recent issues with a mis-oriented circlips? Cost is rising, like everywhere.
Price: ? 12months order to delivery.

Edge Performance EPIX200i (modified and geared snow machine engine)
Pro- High output performance.
Con- Not a robust engine for gross weight cruise at slow speeds. Trouble with cooling in the type of mission a SuperCub will fly.
Notes: Michael at STOL Creek https://stolcreek.com/ has a lot of experience with experimental cubs from working at Turbine Cubs of Wyoming/ Mackey's super cubs. Even though he builds this engine, his view was that it was not the right engine for a cub, and that the Titan O-370 experimental would be better option. The EPIX200i is more fitting for a platform that would otherwise see a Rotax 915is, but wants more power on takeoff. Just heading this one off here...

Viking 195T
Pro- Modern Honda Engine. Well engineered, gear box motor with millions of miles on the road. Good fuel efficiency and MoGas capable. Could fit in the wide cowl.
Con- "its not an aircraft engine" Can you prop start this? No.
Notes- Zenith Owners love them or hate them. Also has a loyal following and good communication from their engineering team, but who wants to go first? Also, squeezes a lot of power from a smaller piece of aluminum. Millions of road miles; very little discussion on this board. What am I missing?
Price: $19k Engine, $6-8k 5 blade carbon adjustable DUC Prop.

Aerosport Power Superior Air IO 375
Pro: Standard stroked design with all new, and lightweight components and injection.
Con: 12 month wait.
Notes: Available with EFII System 32 or Emags makes automotive sparkplugs available. Mechanical or full EFII injection are about the same cost and weigt. From conversation, sounds like +95% (he says 99%) of new experimental builds use at least duel e-mags or EFII.
Price: $47-49k. Includes all new case and parts. 8-12months order to delivery.

Rotax 916IS
Pro: 160hp, 200lb, E10 Mogas capable, Turbo, very efficient fuel burn. Constant speed prop. 2000hr TBO
Con: New engine. Sounds like mosquito from far away. Sounds like a predator drone close up.
Notes- Price? Enough power for a 2300lb gross weight super cub? Going into LSA carbon cubs, 2025.

I don't mean to tip any apple carts with this post, but I assume that there are some people out there with a good amount of knowledge regarding these, and other experimental engines that could be a good candidate and move the "sweet spot" forward.

 

[stewartb]

Your list is all over the place. What HP do you need? What’s the gross weight? Planning for a constant speed?

I’m pleased with my Thunderbolt IO-390. It pulls my airplane pretty well.

 

[Charlie Longley]

Will an O-540 fit in that bad boy? I like that engine in the Pawnee. Seems like it could be reworked a little.

 

[Mudofficer]

Hi StewartB, This post is in reference to an ongoing thread about the new Javron 4 place cub.

Several members, including myself with a down payment, are on the waitlist for this new Javron kit. Very similar to other Javron Cub Clones, but with an experimental clean-sheet redesign of the certified 4 place fuselage available from Airframes Alaska.


From Javron, The fourplace incorporates these features:

44” inside width.
Top longerons all the way back with no gingerbread for a huge baggage area.
24” x 25” baggage door on left side. (expanded door Modified in the prototype)
Folding and removable rear seats. (flush mounted floor Modified in the prototype)
Uses stock Cub wing, lift struts, shock struts, tail surfaces, gear legs, and front seats. (Cessna style seat rails Modified in the prototype)
20” longer than stock fuse to increase the CG envelope.
Single center stick with dual option.
Hanging rudder pedals on both sides with toe brakes on left side is standard. (heel brakes, modified in the prototype)
Overhead flap lever on left side.
HD extruded aluminum lift strut package.
Dual throttles with linkage and cables.
Enlarge round tail.
Composite nose bowl with aluminum cowl panels. We are trying to develop a composite cowling package if time permits.
Sheet metal boot cowl with titanium firewall.
Electric trim.
Routed carbon fiber floor boards.
Tested to 2500 lbs. wings to 2300 Lbs.
Shooting for 1230 empty.
90” flaps and 102”ailerons.
Extended square tip wing with 90” flap length.
24 Gal. fuel tanks.
Clear or tinted windshield and all side glass.
Dual doors; split or one piece swing up.
Conical engine mount with zero thrust angle.
Acme Gen 3 main gear shocks.
Grove 6” wheel and double puck brake package.
3200 tail wheel
Ballast brackets in tail.

Personally, I am looking for an engine that I can run lean of peak with MoGas that will not disrupt ideal cub CGs and turn a constant speed prop. Planning on a Dynon EMS, probably EFI with one e-mag.

 

[Mudofficer]

Charlie, Got an 0540 in my Cherokee 235 (1550 empty, 2900 gross weight), but it is Very heavy (+370lbs). Its a great engine, but still seems to large for this. Feels like there is a breakpoint here where the big 12gal/hr engine would just be building too much plane.

StewartB, is 308lbs an accurate weight? Airflow Performance or Avstar Injection?

 

[Olibuilt]

I was also looking for an engine upgrade for my stock Lycoming O-360 C4P, to have more hp-torque, and constant speed prop ready..






- AeroSport Power O-375 upgrade crank was my first choice. Light and affordable. But They had crank backorder issue when I was ready.



- Thunderbolt IO-390 was also an option. But the added +40lbs in the nose would mess my w&b..



- The lightweight AC Aero (i) O-409 is the option I'm still looking at. More info would be appreciated.

 

[stewartb]

Lycoming specs say the difference between parallel and angle valve 360s is 23#. A 390 won’t weigh much more. I’d guess I got at least half of that back with the Superior cold air sump. The AC engines are interesting. Some of their weight savings comes from leaving off the accessory case. I believe they will do the accessory case option but you can’t just add an accessory case to one built without it.

To the 4-place airplane? It’s very popular here in AK. Kirk Ellis is the best authority on the type. He uses 0-360s in most of his builds.

 

[stewartb]

The AC liquid cooled cylinders are interesting. I think they have potential in the tightly cowled go-fast airplanes. In a slow flying Cub? Not so much. My 390 has 10-1 compression and CHTs run in the low-mid 300s. Lots of hotrod engines struggle to cool CHTs, so I think the big angle valve heads work as designed.

 

[supercub83a]

With the four place you may want more weight on the nose. Maybe an io-390 or a copy of the cc393i would be a good engine? Cubcrafters has become the apple of the airplane world and I dont think they will sell their cc393i except for use on their products.

The AC aero stuff seems really interesting. You will truly be experimental with them, though. Im anxious to see how their engines fare.

Is there a constant speed prop made for the UL power engines that has a proven track record? Can you put a hartzell or whirlwind on it? I remember that being a concern for me when I was engine shopping a few years ago. Their higher rpm will likely require a shorter prop, maybe less thrust for a fixed pith or cs prop.

Great writeup in kitplane February edition on engine selection.





Sent from my iPhone using SuperCub.Org

 

[skywagon8a]

You mention several uncommon engines. What is your normal radius of travel? Are you likely to extend your travels to out of the way places? What if you are in some remote location and you have some type of failure? It doesn't need to be a big failure, yet you could be stuck. Having a popular/common type of engine will make finding a part to get you home easier. I knew someone (not me) who had to have an engine flown into the backcountry of Canada to get his 185 home. Very expensive operation. What if he had one of those off the wall engines? It's likely the airplane would have become a resident of the backcountry. I had a simple thing like a voltage regulator fail on a remote Bahamian island. Fortunately I had suspicions and had a spare or I would have been stuck.

 

[aflyer]

Yes 8a
I would love the engineering challenge of building and flying one of the new engines, but I would have to be based in the midwest where there are airports and emergency landing spots everywhere. In the mountains or Alaska your neck would be way out there.

 

[bcone1381]

Think Utility.

My first recommendation is think about the weight and balance of a completed airplane. You control the weight of the engine and that decision is the largest single factor in it Utility.....or load carrying capability. If you go too light on your engine you can have tramendous issues the CG when you load it. How do you fix that issue with ballast?

Too heavy of engine then you need ballast in the tail. If the wieght of the engine hits a sweet spot, you can load anything or nothing and be fine....never having to think about CG. You wont even know you how good the empty wight CG is because it requires no thought. Thats a valid goal.

 

[spinner2]

I started this thread about a year ago for the very same application. https://www.supercub.org/forum/showthread.php?60530-What-new-engine&highlight=O-370+Titan

I ordered a Hartzell 83” Trailblazer prop, which took 6 months. And I have a Titan O-370 on order. The other engines I considered was the O-390 Lycoming or a standard O-360. At the moment Titan’s prices haven’t caught up to the other builders.

My opinion is that the 6-cylinder Continentals just get way too heavy and thirsty.

 

[stewartb]

You mention several uncommon engines. What is your normal radius of travel? Are you likely to extend your travels to out of the way places? What if you are in some remote location and you have some type of failure? It doesn't need to be a big failure, yet you could be stuck. Having a popular/common type of engine will make finding a part to get you home easier. I knew someone (not me) who had to have an engine flown into the backcountry of Canada to get his 185 home. Very expensive operation. What if he had one of those off the wall engines? It's likely the airplane would have become a resident of the backcountry.

Why? I had an engine fail away from civilization. A Continental IO-360KB. A rod broke and pounded a gaping hole in the case. No option but to let it sit and buy a new engine. Nobody in the country had one or parts to build one. I had to go to the factory. I don’t recall exactly how long it took but it was 3+ months. I chartered a 206 to fly the engine and I flew two mechanics out in my 180. We changed the engine on a Cessna floatplane on a muddy riverbank without a hoist. Three guys lifted that engine, then two held it while one bolted it in. The engine mount on a beached floatplane is way up there. You do what you have to do. I have fond memories of those days.

 

[Olibuilt]

Found a post about the liquid cooled AC Aero:


" Gladiator LIO-390 Engine is built and waiting for the dyno. 259lbs with 2 alternators, starter, flywheel EFII systems and wiring. We are going for 260HP. l can run Avgas or mogas. two water pumps, three radiators (incl oil), possibly ground fans and a few other things. "

 

[skywagon8a]

Found a post about the liquid cooled AC Aero:


" Gladiator LIO-390 Engine is built and waiting for the dyno. 259lbs with 2 alternators, starter, flywheel EFII systems and wiring. We are going for 260HP. l can run Avgas or mogas. two water pumps, three radiators (incl oil), possibly ground fans and a few other things. "

View attachment 64735

I'd be shocked to find them getting 260 HP out of this four cylinder engine without a turbo. That's a lot of HP per cylinder, must be really high compression.

 

[stewartb]

Air cooled 409s can dyno that. Dyno testers can do some tricks to get the dyno rating up. Those tricks are marketing tools since they aren’t applicable to a flying airplane. The question every buyer needs to ask is what’s the as-installed power rating?

 

[Olibuilt]

The question every buyer needs to ask is what’s the as-installed power rating?

I agree that those numbers looks too good to be true. But how can that "as-installed power" be measure??



Here is another example found on Barnstormers:

Engine just got built by Lycon and is ready to ship. 0-375 237hp on the Dyno and weighs 220lbs.

 

[stewartb]

Those guys are famous for big numbers. I’ve asked Superior and Lycoming why their ported/polished/balanced engine dyno numbers don’t match Lycon’s. They politely avoid saying anything other than theirs are accurate. I suspect that translates to they install exhausts and warm up their engines before the dyno run. I wish there was a standard for dyno testing.

 

[Bill Rusk]

It is known in the industry as "California Horsepower". Or the California conversion factor.

My 0-360 weighed in w/ alternator, flywheel, dual Pmags, and starter at 263. I later saved exactly 7 pounds with the magnesium sump so it would have come in at 256.

We will weigh the new Penn Yan engine when it comes in. I am having the scale recalibrated this week to make sure it is an accurate measurement.

You can certainly affect the CG by using a heavier engine, and/or prop, but a better technique might be to adjust the engine mount. Which we will be doing and documenting.

Bill

 

[Olibuilt]

I 'm looking to have more hp and torque, but reliability and weight are always a concern.



Here is another quote:

"10:1 pistons added to the already stroked 409. Last Dyno produced 273HP. runs smooth and very cool."


How many "as-installed" HP you think it really is?

 

[stewartb]

Oli, I sent you message with a name to ask. My guess is 245-250. I’d like to know what you find out.

 

[DENNY]

You mention several uncommon engines. What is your normal radius of travel? Are you likely to extend your travels to out of the way places? What if you are in some remote location and you have some type of failure? It doesn't need to be a big failure, yet you could be stuck. Having a popular/common type of engine will make finding a part to get you home easier. I knew someone (not me) who had to have an engine flown into the backcountry of Canada to get his 185 home. Very expensive operation. What if he had one of those off the wall engines? It's likely the airplane would have become a resident of the backcountry. I had a simple thing like a voltage regulator fail on a remote Bahamian island. Fortunately I had suspicions and had a spare or I would have been stuck.

Read this! Then read it again. Think for a some time about what type of flying you want to be doing. Read it again. I just got home from a solo Moose hunt landing on skis with a heavy winter camp. I run a stock 0320 (160 hp) if I had a issue most every part could be found local and fixed as soon as someone could get to me. If you are building the 4 place to fly runway to runway with next day fedX go for the moon!! I had Jay come up with a custom mount so I can run Bendix mags because I can find or get one fixed most anywhere. Big HP is nice to have but good basic pilot sill is still the gold standard.
DENNY

 

[skywagon8a]

Something for those of you who want to hop up your engines by whatever means and whatever oddball brand to get more power and then still use a fixed pitch prop to think about ........ install a constant speed prop with new carbon fiber blades. The constant speed prop will allow your current reliable engine to turn to it's maximum RPM where the power resides. Don't leave the power you have now behind. Though not common, there are electrically controlled props available if your engine can not operate a hydraulically controlled prop.

 

[Olibuilt]

AC Aero 409 engine:

" 267.6 lbs Weight with everything but mags, including intake, throttle body, starter, flywheel (using heavier front Gov case), and dyno sheets at 2700 and 2900 rpm. These are real world numbers without optimization, to represent the same parameters as this engine will be running in the aircraft. "

Dyno sheet:

 

[stewartb]

Mudofficer, I’d suggest you add two more potential suppliers to your list. Thunderbolt and Aerosport Power. Thunderbolt is Lycoming’s custom shop for experimentals, Aerosport is open source and famous for building the range from stock to as cutting edge as you want to go. In my mind they’re the two top shops. You’ll learn more from those two phone calls than in 20 pages of internet chat.

Good luck with your decision.

 

[Rob]

Everybody enjoys a different facet of flying and a different path to get there. I'm far more enamored with the idea of hoping in an airplane and flying it somewhere than trying to figure out how to get it to shave off a few more feet or carry a few more pounds. There are already better mousetraps readily available for those tasks, that have reliability beyond the one-offs.
Not saying there's anything wrong with the entrepreneurs in the bunch, just saying it's not why I fly. Pick your engine for why you fly.

The man in the following snip needs his engine to light each and every flight, leaving the homestead or the bush... my mindset follows. And although I too relish the thought of defeating adverse moments when they come, I see no merit in targeting failures looking for a place to happen, life has a way of dishing out adverse moments, I prefer to stack the deck in my favor.

To the 4-place airplane? It’s very popular here in AK. Kirk Ellis is the best authority on the type. He uses 0-360s in most of his builds.

To the poster advising selecting an engine based on weight, I'd say you're idea of CG is flawed. The ONLY time you'd have to be concerned of an engine weighing too little is if it weighed NOTHING.
Engine on the top 750 HP / 331 Lbs.
Engine on the bottom. 600 HP / 640 Lbs.
Same airframe


As Bill R said, there are better ways to address CG than engine weight. IMHO same goes with ballast.

Take care, Rob

 

[stewartb]

The OP stated he wants to run LOP. That means fuel injection and to make it better, electronic ignition. In each of those he can choose mechanically driven or fully electronic. Fully electronic provides the best fuel and spark control. Regardless of whose case and cylinders a guys chooses, fuel and spark make them go. Fuel and spark are a big part of an engine decision. Neither compromises engine reliability.

 

[ak49flyer]

Actually they both can compromise reliability. I’ve seen electronic ignitions and EFII systems both have intermittent failures/anomalies, which are definitely reliability issues, in my mind. Have also had issues with mags and carburetors, to be fair…

 

[Olibuilt]

I'm far more enamored with the idea of hoping in an airplane and flying it somewhere than trying to figure out how to get it to shave off a few more feet or carry a few more pounds. Pick your engine for why you fly.

A dozen years ago, right after my first solo float flying my 180hp SuperCub, same day, my instructor made me fly is Cessna 172 floatplane equipped with a 0-300. 2 persons, fuel gas, no baggage, hot calm day. After what seems like a minute an a mile long takeoff, we struggle to gain some altitude.

You have to be very talented to fly an under power plane. I think power is a safe assurance in my case...