Just a couple of months ago, Daniele Sabatini sent me photos of the brand new Nembo Super 32 inverted 3 cylinder engine. It caught everyone by surprise, to say the least, and much confusion ensued in the comments. Some of you weren’t even sure they could build a motorcycle around that engine. Daniele chose to answer his critics by continuing his work and I just received these construction photos with the engine in place.
The bike looks like it will come in about 150kg or 330 pounds. The 1814cc engine on the dyno is delivering power and torque above expectations with no vibrations.
You could call this out of the box engineering, but it looks like they just threw away the box entirely and tried something new. Daniele says sound files are coming very soon. You know, I really like the way these guys think!
More photos below:
Mark says
Inverted….. why???
Phil says
why inverted? What’s the point, besides a «can we do it?» contruction process?
WestOfBen says
That exact question was debated with a lot of heat some time ago. You’d get a laugh out of the original comments.
Some of the reasons being: better cooling by way of less impeded airflow, exhaust on trailing side of engine, mass centralisation?
Richard Gozinya says
That’s one seriously lightweight bike for such a big engine. As to why, well, without people like this experimenting, nothing ever changes. Maybe this’ll be the next big thing, maybe not. But with as little innovation in the motorcycle industry as it is, it’s great to see someone step outside of the box and try something different.
Thom says
Kinda reminds me of the Munch Mammut…. Who cares why? It’s freakin’ cool!
mark. says
I notice that they haven’t a chain fitted, though the run looks like it is going to be quite interesting. I wonder how this puppy will handle coming out of corners with the power on. Could be very amusing.
mike says
well, would be nice if they could get it figured out, all the bugs and stuff, get a production plan and business plan and get them built, would be no different than BossHoss, with the big V-8’s. Not a bit of difference 70 years ago when everyone in aviation said radials were the only way to go, and then someone inverted a V-12, everyone asked why then too.
1, damn good looking bike
2, great idea
3. who cares what people think about your build, keep doing it
4, follow the first three
Emmet says
damn! This bike excites me, maybe because I love things that come in 3’s. For such an innovative design, I wish they did away with the conventional forks (no I’m not ungrateful, I swear!!)
Cab says
Seems like keeping oil out of combustion chamber might be tough. Probably eats up the piston rings quick. Easy to foul up all kinds of measurements on valves/seats. They better have a damn good oil management system, pump will have to work double time, is the tank before the gas the oil reservoir or is that a radiator? How long will that chain be?
Aside from that, yeah it looks cool an thats a-lot of engine for weight.
wade says
astounding progress of innovative design.
leston says
hmmm yes
JR says
Nice! Bet it will sound awesome!
Dry sump oiling I assume. I like how the exhaust is routed.
Ted says
This set up flies in the face of keeping the mass as low as possible for good handling
Bob Nedoma says
Ah sure hope this is DRY SUMP engine.
Jonas Barna says
I am wondering how much oil would the engine burn, throu the cylinderhead after 40 thousand miles or so…
Scotduke says
Can’t see the chain side and yep, it is curious where the chain will go. At 150kg it’s pretty light – I’m curious too about the COG tho I expect the team have found a way round this.
Wol says
@ Emmet, I love it as well, but i think a lot of the reason the engine is inverted is because they have accepted that the conventional forks are to be used. They have replaced the a major part of the frame with the engine cases by placing them so high and support the head stock. I’m sure they can’t wait to see it running either! it’s crazy good.
Iperpaolo says
I am very curious! have you seen how long is the rear swingarm?
Jim says
330# is light for 1800+cc bike, heck it’s light for a liter bike. To get there the builders are likely using some expensive and expensive to manufacture materials. When a price becomes available, a frequently written comment will be; This is fantastic and if it cost $9,000USD I’d buy one, but its way to expensive.
Sorry, feeling cynical this morning. Trying to get over it before the holidays.
Scott says
I have no idea if it will work or not, but I love the fact that there are people continuing to ask: “why not?” rather than “why?”
Without mutants, we’d have no evolution. 99% of them may die off with a wimper, but with enough creative people, someone will find something unique that works.
Basic motorcycle configurations have been stagnant for too long.
Scott says
. . . with that said, the more complicated drive routing combined with the elevation of the center of gravity resulting from bringing the transmission up would be two big theoretical disadvantages to such a design.
Scott says
I notice there’s no chain in the photos. Is that because it would not only look odd, but dangerous to have the chain stretched all the way up there?
Performance may suffer without a chain.
MikeC says
All,
If you have a look at the photo of the rear, you can plainly see the countershaft sprocket to the upper left of the rear tire. It appears to be below the clutch mainshaft, and likely directly inline with the rear axle/swingarm pivot with a moderate amount of sag – probably where it should be. Not sure about the swingarm angle to horizontal though. May cause some odd torque transfer… Overall, I think it looks very interesting and encourage the build further. Lets see it running. Great job.
DWolvin says
“Performance may suffer without a chain.”
Jerk; I was just taking my first sip of coffee this morning, I almost lost my keyboard.
But thank you for the laugh!
PNichols says
Seems ironic they take the photos in front of a radial engine. The term “hydraulic lock” comes to mind. Will you have to pull the plugs and rotate the crank through a few times before you light it off? Like a lot of other people, I do like the thought process.
Will13 says
Great Stuff! Very glad to see a prototype worked up.
In terms of the inverted design, de Havilland built the Gipsy III engine prior to the second world war, which was an inverted air cooled 4 cylinder that powered a variety of aircraft. The German aviation industry took inverted engine design to the next level with the DB601 inverted liquid cooled V12 engine which also used direct fuel injection. The DB601 powered some of the highest performing aircraft of the era, such as the legendary Me109.
So I’m pleased to see Nembo in route to attempting this engine concept in the two wheeled realm. With the power to weight ratio they mention, it will be very exciting to see what comes out of this new machine.
sluggish says
People, the oil management problems aren’t that hard. Here’s how I’d do it:
1. Separate oil bath for cams, splash lubrication. No supply or scavenge lines to worry about; run a belt for the cams instead of a chain.
2. Roller crank with splash lubrication. Keep about 10 to 20cc of oil in the crankcase at all times–it will get flung off the back of the pistons and into the bearings. You’d have compensate for whatever leaks past the rings, but that’s just a metered drip out of your main oil supply.
That took longer to type than it did to invent. Now, both of those ideas probably suck and wouldn’t work. I’m guessing if anyone spent a couple years playing with actual hardware they’d have a solution that would work, and I’ll grant this design the benefit of the doubt until it does blow up.
Kai Ju says
Looking at it from a mechanics point of view I’m curious how much fun it will be to check and adjust the valves. If it’s shim under/over bucket the buckets/shims will fall out as soon as you pull the cams and it’ll be even more fun to hold everything in place while you try and get the cams back in.
Even with a drysump system the oil on the cylinder wall will collect above the oil control ring and then work it’s way past the ring gaps into the combustion chamber.
I’m all for out of the box thinking but practical issues, such as normal maintenance, have to be considered as well.
Thure says
Great looking bike, personally I would want the bars a couple of inches higher. Maybe I’m getting old….
hoyt says
light weight? The wheels, swingarm, and bodywork are carbon fiber, so the bike can be very light.
chain routing? How much lower is the Yamaha R1’s stacked transmission than the transmission depicted above?
I’m interested in seeing the result of their efforts. Good luck. (nice touch by having the radial in the back ground)
Dr Robert Harms says
I don’t understand. While an inverted engine makes sense on an airplane (lowers the cowl and propeller for increased visibility) I do not see any advantage for a motorcycle. Raising the crankshaft moves the mass up when handling would dictate that it be lower rather than higher.
Paul E. says
Kinda like an upside down 3 cylinder Cannondale. I do wonder that the fuel and cooling top mounted and the crankcase @ your knees might feel a little “tall”. It’s a damn sexy machine, and I’d sure like to see a track report on it.
Yeti B. says
It weighs 330 lbs in racing trim (stripped to the bare essentials). If you were to make the bike street legal with lights, mirrors, wiring, instruments and a noise/emissions compliant exhaust system, it would add roughly 40-60 lbs, making it about the same weight (400 lbs) as any other modern sport bike.
I’m not convinced of the merit of inverting the engine, but I’ll hold my opinion until they rack up some miles on it.
Who knows, it might actually be the greatest thing since sliced bread… I seriously doubt it, but I’ll wait and let the wear and tear of riding be the judge of that
S.K.Jones says
Actually, this design might handle quicker than a conventional motor configuration. On a motorcycle that has to handle quickly, getting all the weight as low as possible is not an absolute good, what is important is to concentrate the weight as close to the CofG as possible in order to minimize rotational inertia. When you lean a bike over, it actually rotates around its CofG under the influence of countersteering. With a rider, fuel etc, the CofG is probably about 30″ off the ground, so this configuration puts the weight of the crank, clutch, transmission and crank-case as close to the CofG as possible.
Might work very well indeed. Damn cool lookin’ too.
klr-dude says
i once saw an inverted engine in a submarine the reason was that in case one piston had trouble, the conecting rod could be disconected from the top and the engine would remain operational .
ofcourse this is not the case here .
i can not see why this would have an advantage over the conventional set up .
does anybody know what the claim to fame is ?
there must be a reason other than just trying to be different,i would think
wade says
i agree at first glance with Ted. however, the profile view sent my mind to visualizing the center of gravity and the bike at first looked to be top heavy. Then after consideration of the “underside” components of the bike along with other forces beyond the static effects and allowing the added weight of rider, well, Let’s take her for a spin!
aichbe says
The designers will probably have to design some special tools to work on an USD engine. Maybe they’ll have to be in a pit under it, like the “quickie oil change” stores. The WW II German Me/Bf 109 was easier to work on than radials or conventional V-12s, as the mechs could just stand under it to service the FI or the heads, plugs, and valve gear rather than crawl all over the cowl and engine assy, and pulling a single piston/rod assembly, or checking the crank would be easier, and less messy; inbolt the big end rod cap, and the piston drops out the bottom. This unit would have to be a dry sump, with high pressure oiling to specific areas like cam and crank friction surfaces, and at least one or more evacuation / scavenge pumps to keep the oil from pooling in the cylinders or other low spots, like on a Harley . As far as how the weight is distributed, it does seem to be too high. I’ll wait till I see it as a runner, if they get it that far. This may not be the final engine design, just an engineering test mule.
aichbe says
I noticed that changing plugs would be easier than any 4cyl sportbike. The chain will be very long, or else will have to have a jackshaft using 2 shorter chains; at least there’s a sprocket on the wheel. They’ve got to have a $mil or 2 already into it.
Rich says
If comments on this have already been made but a quick scan of the posts did not indicate that it was.
As I understand contemporary engine design, it should begin with the combustion chamber itself and work out from there (after the preliminary layout is established, e.g., number of cylinders, cylinder configuration – v, inline, etc. and so on). The combustion chamber is the most critical component since it effects combustion efficiency. So – what am I getting at?
Look at the torturous route the air must follow to get into the combustion chamber. Contemporary engines now strive to have a straight path for the air to flow. A simple examination of any of the cylinder-head cross-section drawings will reveal as much. By choosing this design, I fear he has compromised the potential for maximum volumetric efficiency.
Lastly, he has moved the largest mass to a very high location undoubtedly raising the CG. This will significantly increase pitching moments and affect stability under braking and acceleration. I fear he does have a case of “because I cannitis” and has not designed the bike package from first principles.
hoyt says
The picture above with the rider illustrates all of the heavy parts (including the rider) are very close to one another. This must be one of the advantages they are attempting to explore. A Gold Wing handles well for its size not just because the c of g is low, but because the rider is low as well.
Who knows if this effort will yield a proportionate advantage in handling. It is great to see this level of R&D done to the i-c engine after 100+ yrs. (don’t forget Ecosse’s opposite effort to lower the bike for better aerodynamic reasons). In search of the holy grail (“blue, no green, “)
Luke says
Rich – is the airflow really torturous? It looks like it has a long shoot to follow (new meaning to “downdraft’). I’d say it also adds volume to their airbox.
The airflow has a bend getting into the head, but so do all other engines somewhere along their path.
dj says
From my point of wiew (grad. mech.eng) there is no advantege on this.
All I can see is trouble with lubrication, high oil consumption, poor cooling of the exhaust pipes. After stopping engine there is no way to stop lub oil from cyl liner to drain in combustion chamber, means heavy smoke on every strart if no trouble with spark plugs soaked in oil…
Advantage? None
Dr Robert Harms says
What would the torque reaction be at idle and when making an off idle turn in whatever direction is opposition to the rotational force of the flywheel? Presumably it would be exacerbated
due to high placement of the rotational mass (??) . I would have to agree with the chain length and path as being problematic
Oldtimer says
I think I’ll just wait and see. I really don’t think the builders and investors jumped in and built this thing without considering the concerns voiced here, and probably more that haven’t been brought up.
To get something “innovative” to the point of actually building it is a monumental task, well beyond the capabilities, desire, or means of most. They are not dummies.
The usual rant is long and loud about the lack of innovation in the motorcycle industry. Here is something a little different, and many are quick to condemn it as folly.
I don’t think they built it “because they can”. Probably more because “can’t” is the first reaction of most “reasonable” people!
JR says
“We will see” is the recurring theme. And I can’t wait to see.
Marvin says
When you sit up on a bike to go into a corner you are instinctivly raiseing your centre of gravity because that way you don’t have to lean as far for the corner speed thats why supermotos can out corner superbikes given the right set of corners. In the corners it may be an advantage to have a concentrated mass near the COG just before the corners under braking with conventional forks things might get interesting. The bike look pretty much built to me so I guess our corncerns will be answered or realised but either way they sould be applauded for cutting the metal so we can know. If that is the external oil tank next to the fuel tank its in a far better place to get to than my Yams. What I really like here is the look of the frame if we can still call it that, its been reduced to essentially just bracketry to hold the steering head and seat. The bike looks like it just grew out of the engine. Even if it has lots of problems it is still 150Kg bike with a lot of power that looks good, if its only ever a posers machine it leasts its given the posers something other than a cruiser to choose from.
BoxerFanatic says
As pretty as those cherry red anodized fork legs are…
I’d rather see further suspension innovation, than turning the engine upside-down.
It is one thing to be creative to solve a demonstrable problem.
It is different to just throw reason to the wind, and do something different regardless of a systematic approach to the engineering. The engine may indeed be well built… but thinking of the motorcycle as a whole system, what problem does an inverted transverse engine solve, that a right-side-up engine doesn’t, or even a longitudinal engine?
If one really wanted aft-facing exhaust, why not figure a way to do that with the valvetrain still at the top-side?
I’d rather see more innovation with double-A-arm front suspension, and other chassis innovations, frankly. There is lots of good engine tech out there already without turning the engine on it’s head, literally.
mustridemore says
“Performance may suffer without a chain.â€
My vote for comment of the year !
FREEMAN says
Bike looks great. I can’t wait to see it all put together and running. Keep up the excellent work and smart move on letting your work speak for itself.
Paul Y says
“Conventional wisdom is what’s left after everything else has been tried and found wanting.” I can’t wait to see if this works, and how well. If it is functional the maintenance stuff is just details to be worked out later.
The only real reason for inverted engines was in aero applications, it let the designer keep the propellor shaft up high without the engine being in the pilots line of sight.
The Ranger inverted six, designed back in the 30’s, is an excellent example.
http://www.airvictorymuseum.com/html/ranger_l-440.html
Al Swearengen says
If moving rotational mass higher in a motorcycle had any use, MotoGP bikes would have designs that higher CoG. They don’t.
Which is OK. The builders and investors had their target market in mind, the people who remarked “Cool” on this page. Sometimes low functionality is good, I ride with someone who rides a rear brake-only, suicide-shift Harley rat bike. At stops on hills he has to make sure to stay on his right foot and slip the clutch pedal. Different strokes and all.
Nick5628 says
“Al Swearengen 12.21.10 at 10:05 pm
If moving rotational mass higher in a motorcycle had any use, MotoGP bikes would have designs that higher CoG. They don’t.”
Obviously MotoGP has thought of everything already and will never get any better. I totally agree with your thinking, if MotoGP doesnt have it then it must not be a good idea….. what?
Al Swearengen says
What? Do you think that the designers of this motorcycle just “discovered” high CoG and the jury is out on its value? Don’t be dense. Lower is better because lower has been better for the physics of any high-performance vehicle, motorcycle or car. The science behind it has been settled for a century.
These guys have an interesting design exercise. But it’s not going to perform better than a conventional sport bike. There is no design problem answered by inverted cylinders. As many people have explained in this thread, inverted engines are used in airplanes only because they raise the crankline, which is important when running a big propeller.
Interesting? Yes. Cool? Yes. Useful? No.
Byrd says
Just because you can, doesn’t mean you should.
Nick5628 says
Al pay attention, I was commenting about your logic referring to what you said about MotoGP.
Nicolas says
it’s awesome to see all these enlightened explanations about why and how it can not work, directed to something that exists and does work …
kneeslider says
Let’s see, Checklist before creating a new and unique motorcycle:
*I have to make sure it’s been done before and is widely accepted
*It must be immediately understandable by everyone at every level
*The racing teams and manufacturers must be doing it and/or producing it
*I must have a universal answer to the question “Why?” for anyone who asks
*Anyone who thinks it won’t work, ipso facto proves it won’t work
*Showing I can isn’t good enough, someone else first needs to decide if I “should”
Maybe it’s better to just watch TV.
I could quote myself at length, but it’s easier if I just point you here.
Oldtimer says
@ kneeslider:
AMEN, WELL SAID, YOU’VE MADE MY DAY!!
John S says
“…would be no different than BossHoss, with the big V-8′s…”
Except BossHoss doesn’t mount the engine upside down leaving the 150 lb crankshaft at chest height. And I’m not sure dual Holley’s work upside down. I suspect this bike will be fuel injected. Otherwise it’s just vapor lock waiting to happen.
Victor says
Paul, well said, fantastic checklist and great article, they are two of the reason why I love your motorcycle blog. While many comments above remember me that so fun movie… “Idiocracy”, if I’m not wrong…
hoyt says
Al Swearengen: “Lower is better because lower has been better for the physics of any high-performance vehicle…”
There are high performing dirt bikes that are not low. True, completely different application than a road race bike, but it dents your blanket statement, nonetheless. Plus, GP bikes are not that low. (refer to the M1’s stacked transmission, RSV4, etc.)
Another point is that ideas generate other ideas, so why discount something right away? Reminder: there were many skeptics to motorized bicycles when their horse could roam easily over “roads” while the gear-head fiddled with his oil with one hand & steered with the other as he bounced around on zero suspension.
Suppose someone else has a great idea for an ultra compact head that also blows your mind with solving the oiling topics? The idea to centralize the weight of the heavy “bottom”-end progresses. Not only does this centralize mass but it allows the builder to cut weight of the chassis by bolting minimal frame structures to it.
Mechanical engineering has always been, and always will be, a trade-off. BoxerFanatic’s comment about an alternative front suspension might reduce the bike’s tendency to stand-up while on the brakes in a corner. This configuration is also convenient to bolting a suspension system to it, further reducing the weight of the neck/chassis.
Great list Paul.
rohorn says
Great list, Paul!
hoyt says
…adding super motard bikes: They are not that low and give a racier bike fits in the tight stuff.
It does seem like there are more direct approaches to achieving centralized mass and cutting weight. e.g. make the heads structural like John Britten or something similar to Ducati’s cf frame-and-airbox-in-one design. If the heads on this triple were structural and it was configured in the traditional way, then the fuel tank could be placed lower than the above. There must be other topics being explored.
anyway… It’ll still be worth the effort no matter what the outcome.
k.rollin says
@BoxerFanatic
The aft facing exhaust has already been done without turning the engine on it’s head. See the 2010 Yamaha YZ450F, or any of the bikes seen here: http://www.motocrossactionmag.com/Main/News/THE-LONG-HISTORY-OF-REVERSECYLINDER-ENGINE-DESIGNS-7056.aspx
This design may not be practical, but it sure is cool. The 1.3 L V8 that I’m developing with my professor may not be practical either, but there is still merit in undertaking the design process.
Sid says
k.rollin – 1.3 v8 motorcycle engine? If so, let’s hear back & good luck!
Bazuzeus says
wow, put the weight highest possible, what a great idea !
atones says
Possibly the last truly great, petrol driven motorcycle.
k.rollin says
@Sid
I’m not sure what applications my professor has in mind for the little V8, but I know that I’d like to put one into my cabinscooter project instead of the 2004 CBR600RR engine I planned to use. The design of the engine should be pretty similar to that of the 554 cc V8 that my school’s FSAE team used in Viking XXX.
Dbarrow says
I think that they should make a liquid cooled version of the largest motor they have and switch from the triples to inline-4’s. i think that would make the most powerful bike ever
Jax Rhapsody says
Why does it hafta look like a camel?