Motus KMV4 – the Hot Rod Small Block – More Details Revealed

Motus KMV4 - the hot rod small block

Motus KMV4 - the hot rod small block

It’s often hard to evaluate something brand new until we compare it to something we already know, … or think we know. Last week, you saw the video of the new KMV4 engine running on a dynamometer and some specs were listed on the Motus website. Is it light, compact, powerful and versatile, or heavy, huge, under powered and limited in potential applications? Is it well engineered or primitive? While many of you have opinions, I think you could use a little more information and maybe a reference for comparison.

What better way to get more information than to go to the source, so we did, and I can tell you a little inside info you haven’t heard yet, and to help you put that into perspective, I’ll do a little comparison with something else you may have heard about last week.

A few days ago, BMW released the details of their all new BMW K1600. It certainly seems to be an impressive motorcycle and quite a few websites were quick to present the new touring bike as one more example of Bavarian engineering with a smooth, powerful, light and compact 6 cylinder engine. How does everyone know it’s all of those things? BMW said so. Hmm ... well, let's compare.

The BMW 6 and the KMV4 are so totally different, one the product of refined German engineering and the other an upstart hot rod V4 from the USA, it's obviously foolish to compare the two engines, how could we? Well, ... I have a better question, why don't we? And now that we have more detailed information, you might see the KMV4 in a new light.

Using BMW's own specs as detailed on their website, I began to notice quite a few interesting similarities and, even more interesting, when there is a difference, it usually, tilts in favor of the little upstart V4.

Let's start out with some obvious points, displacement is virtually the same, 1649cc for the BMW, 1645cc for the KMV4.

The KMV4, obviously, has 2 fewer cylinders, a single cam in the valley versus dual overhead cams and 2 versus 4 valves per cylinder so there are fewer moving parts. Advantage KMV4.

Weight of the BMW engine as provided by BMW is 102.6 kilograms or 226.19 pounds. I expect you’ll hear praise for how light the BMW engine is. The weight of the entire KMV4 powertrain, including gearbox, is designed to be under 200 pounds, it's not yet final but it looks to be easily on target. Advantage KMV4.

Engine width: BMW: 560mm or 22.047 inches, KMV4: 492mm or 19.37 inches. Remember, the BMW engine is described on their website as compact. Yes, that’s in comparison to other 6 cylinder engines but you will also likely hear comments praising BMW for their achievement in building a relatively narrow engine. Advantage KMV4.

Torque: BMW 175 Nm or 129 foot pounds, KMV4 162 Nm or 119 foot pounds. Advantage BMW.

Now, this is interesting. All of the horsepower figures you've seen so far on the KMV4 have been target figures and listed on the website as 140 minimum, however, as the video clearly shows, the KMV4 has been on the dynamometer. So what did The Kneeslider find out for you?

BMW 160 horsepower, KMV4 161 horsepower. The BMW 6 makes a little less horsepower than the KMV4 and it has 6 cylinders, dual overhead cams and 4 valves per cylinder. The pushrod, 2 valve V4 does more. Advantage KMV4.

So, just to recap, compared to the BMW, for the same displacement, the KMV4 has fewer cylinders, fewer moving parts, it's narrower, lighter and makes more power. Cool!

Gearheads, being what they are, look at any engine and wonder what they might do to increase performance. The BMW, in order to achieve its compact size, is built with a very small distance between cylinders so no one is going to be over boring the 6 to increase displacement. The KMV4, on the other hand, was specifically designed with extra material around the cylinder bores. This is a hot rod small block, after all. (Hey, Vern, why don't we just bore this sucker out a little bit?) Why not, indeed? Instead of a 1650, how about an 1850?

There have been some comments about the 75 degree crank. Motus brought in Geoff Goddard on the crank design and balancing. Goddard designed the Ford-Cosworth DFV, an extremely successful Formula 1 engine. Motus wanted a big bang, odd firing order, for that cool American small block sound to give it a little character (Yes, I like it!). So the crank is 75 degrees, mainly because he said so. And since he's also worked with Ducati (the Desmosedici V4 crank throws are 72 degrees) they felt he knew what he was talking about. The sound would not have been much different with 90 degree throws, but the 75 also allowed Motus to cancel out another secondary vibration.

The BMW 6 is referred to as very smooth, the KMV4 with a 90 degree V has full primary balance and 2 counter-rotating balance shafts cancel most all secondary imbalances. In other words, the street version of this engine will also be very smooth. For competition, remove those balance shafts and immediately increase power.

Speaking of competition, as already noted, if you need more power, besides boring the cylinders and removing balance shafts, you can increase stroke, replace stainless valves with larger titanium units, increase compression, replace hydraulic lifters with solids, which bumps the redline and all of this basic hot rodding is before any forced induction. Another point, those roller hydraulic lifters are a production GM part, keeps costs down and parts available while maintaining a respectable redline of 8000 rpm. There are several other GM parts in there, too, cam bearings, ignition coil, injectors and more. In other words, parts are everywhere.

The KMV4 was engineered by the same guys who worked for decades at GM Racing, it shouldn't be any surprise that removing the bevel drive gearbox and installing an automotive type transmission would make this a sweet little engine for some 4 wheel racer. Depending on configurations, 230 horsepower is pretty straightforward, perhaps as much as 300 with a bit more work. Coming standard in a mild state of tune it's still quite healthy and yet there’s plenty of room to hot rod this little small block.

You don't need some exotic engine configuration for modern, reliable, high performance. It reminds me of an old comparison of top speed in a car mag some years back, Car and Driver I think. They wanted to find out what race cars were actually the fastest and had a 3 way test with an open wheel racer, an F1 car I think, a LeMans racer, Porsche, if I remember correctly, and a NASCAR stocker. The various teams showed up, the F1 car did OK. The Porsche was accompanied by a team of technicians who hovered over it and tweaked and tuned everything and set down a respectable speed. Then the NASCAR boys showed up, rolled the car out of the trailer, fired it up and blew them all away. So much for all of that finely tuned European technology, welcome to America.

Are you beginning to see what this engine is? Anyone comfortable with hot rodding a small block Chevy will be right at home here. For those making comments about how Motus needs an engine for multiple purposes, what exactly do you think this is? This is a small block with loads of hot rod potential capable of being fitted into all manner of vehicles and garage projects that you ride, drive, float or fly. It's a clean engine with the modern GDI fueling necessary to meet current and future regulations, too. If Motus does this right, this could be one amazing little beast, and by the way, it's made in the USA.

Link: Motus Motorcycles
Link: BMW Motorrad

Related: KMV4 engine video


  1. discontinuuity says

    161 hp, now that’s more like it! I could also see this with a small supercharger replacing that big air box.

    And if it bolts up to a car transmission it would be great for a Lotus Seven replica or another kit car.

  2. mxs says

    As exciting as it might sounds to some, what’s the obsession with 1600cc sport touring bikes?? Why does one need such a large displacement, HP and torque? Are they assuming that everyone is pulling a barn behind, or having the whole family seated on the bike??? I just don’t get it.

    Now, your second last paragraph is just silly. I think you know that, I guessed you got carried away a bit. No problem … :-)

  3. Simon says

    Indeed, an F1 car can drive upside down at top speed, a NASCAR won’t do that 😉
    Motus have produced a cracking new engine, no denying that, but maybe it is a bit much. Although I have yet to read anywhere that the VFR1200 is overpowered.

  4. Tyler says

    Am I the only one who thinks this would be a scary delight in a side-by-side ATV (Kawa. Mule, John Deere Gator, etc…)? Plenty of room underneath the dump bed. Just saying.

  5. JR says

    Can’t wait!

    I want them to make an entry level bike with this engine. CAFE RACER!

    (Shelby Cobra of the motorcycle world)

  6. kneeslider says

    mxs, “Now, your second last paragraph is just silly.”

    Well, it sounds silly, but that article really did appear and happened just that way, (I’ll try to find it), but the point is that everyone looks down their nose at a pushrod OHV engine and can’t imagine it’s up to competing with all of the other fine multi valve overhead cam engines out there. Some comments after the video seemed to suggest the V4 was off the mark, why not this or that, too big, too heavy, etc. I say, why not look at it without any preconceived ideas and see how it performs.

    This engine is as highly engineered and capable as any other motorcycle engine out there, and before anyone thinks it’s not suited to the sport touring application Motus is planning for it, reserve judgement. You might be surprised.

  7. todd says

    I’ve put thousands of miles on bikes with as little as 33hp (even less on some others). I’ve never felt any sort of long distance disadvantage. HP will win you stop light races and bold conversation. That said, it’s very difficult for a motorcycle manufacturer to come out with a bike that makes perfectly adequate power. No, it must be more than any normal person could ever hope to utilize. Only then will it be acceptable to the buying public. Who cares? Go out and buy your 160HP or 200HP bike and ride around at 20HP.

    What matters is that Motus has some critical backing in the industry. They must play this up to the fullest extent possible. BMW has their roundel and that ends the conversation right there whether it’s worth it or not. Motus needs to prove itself to become accepted – obviously, judging by the sort of comments on The Kneeslider.

    Now, ask yourself if that good old NASCAR ever needs to accelerate or go around corners like an F1. Apples to oranges. I bet there will be a time I’ll come roaring up behind one of these on my local roads. Won’t that be something?


  8. John says

    I remember the Nascar comparison to all the other race venue cars, and the Nascar beat them all and with a big boxy brick of a car and so called “inferior” pushrod V8. I think that was mid to late 80’s, I hope you can locate it Paul.

  9. Tinman says

    There is a whole generation out there that is addicted to High Tech, In the real world simpler is better. Harleys are made fun of, and 2 valve Vettes are under rated. Both vehicles complete their mission perfectly, but the Teckys are not satisfied… Ive found that most Old School guys enjoy tinkering with their bikes and cars where the new school folks are content to buy the package and just ride it. Its all Good, and thank God we live at a time that we have choices. The Motus looks good to me!!

  10. Will13 says

    This is fabulous news, particularly for a young American company attempting to enter an insanely competitive market. What remains to be seen is an actual Motus motorcycle, in the flesh doing laps at one of America’s best circuits. While this will no doubt be happening very shortly (at least I hope so), it will all come down to the all mighty dollar. Can Motus produce a complete machine (or supply its incredible engine to someone who can) and sell it to the public at a competitive price. The Roehr 1250SC comes to mind as a fantastic, well engineered American bike that struggles in its home nation because of production costs.

    The fact that Motus has concentrated on power train development and produces its product right here in America must be applauded at these challenging times, and I wish them nothing but success. Perhaps they could consult with All American Racers and offer the Motus V4 as an option in Dan Gurney’s Alligator, which is now undergoing testing with an S&S V-Twin. The combined efforts of AAR and Motus would surely result in something spectacular for all of us that are fans of the American Sport Motorcycle industry.

  11. says

    1600 cc motorcycle engines?
    PGO, a Taiwanese scooter manufacturer, revealed a liquid-cooled 1600cc v-twin sportbike at the 1991 Milan convention. So this size is not unheard of. It’s not as though Motus is pulling off a BossHoss adaptation. Their motor is a purpose-built motorcycle engine.

    todd- the difference is all in the hands of the rider. Apples to Oranges? Right. That is a good lead into a discussion about the chassis. (which, by the looks of it deserves quite a bit of print as well). What a combination with that motor.

  12. Rich_Too says

    The F1 car and a Winston Cup stocker were built to do different things. To only judge their abilities with a top speed run is rather silly. An F1 car is an open-wheeled racer – which significantly increases drag. It also has rather high drag as a result of its wings and ground effects devices. Are you seriously touting a Winston Cup car as being a superior machine? If so, that’s absolutely ridiculous. Let the two cars compete on a road course – it would be no contect.

    Also, the BMW engine is deliberately tuned for a very flat torque curve – it has less power than the S 1000 RR – for acceleration without the need to downshift. The Motus team is to be commended for their efforts. But a little objectivity on your part would be nice.

  13. says

    Paul – Very entertaining write-up and it hit the mark on several topics.

    Nothing wrong with the BMW angle. Nothing wrong with the Motus angle. Both very cool to have on the market.

    We now have an equivalent 2-wheeled Lemans roster. Who doesn’t like seeing diverse vehicles such as a ‘Vette mixing it up with Europeans and Japanese? Now the Sport Tourers can hold a 24 hour race series.

  14. says

    Rich_Too – read between the lines. Do you seriously think Paul or Car and Driver thinks a NASCAR would win a roadrace over an F1?

    the point is: what many consider low tech is not necessarily an achilles heal. “Pushrods? oh, that must not work.” Please.

  15. says

    Just because it needs to be asked… are there any plans for a V6 version? looks like there is room and if in the same state of low tune it would be a stump puller right out of the box

  16. Chris Y. says

    This is mostly just conjecture and bench racing. As any gearhead can tell you, specs are great, but how does it all perform in real life?

  17. JR says

    @Viv Collins

    A V6 would be fantastic! Don’t make it any bigger either. Or even better… smaller. How about a 1000cc V6. Wouldn’t it be cool to have a new Laverda V6.

    My brother has an 84 Honda VF700 V4 with (almost) open exhaust, and that thing sounds like a little small block V8 at idle and screams at rpm.

  18. Rich_Too says

    @ hoyt – pushrod motors are fine up to a certain rpm where an OHC engine can keep increasing engine speed and the push rod motor can’t. Push rod motors are inherently limited by their valve train – which is fine as long as everyone keeps that in mind. One could say that this rpm limit is a kind of Achille’s heel.

    I mean, there is a reason that OHC engines can spin at ridiculously high rpms – and no MotoGP bike or F1 engine uses pushrods.

  19. jim says

    Love the sound! I hope this one makes it to production. Pushrods are fine for anything that doesn’t turn much past 9,000 rpm — and like any good pushrod engine with up-to-date design, the KMV4 can be tuned for a number of applications, from a barn-door touring rig to a screaming crotch rocket, and anything in between. 160 hp is, in my opinion, all the power any motorcycle needs. 200 hp is insane power for any street bike, and very few everyday riders have the skill to use it.

    However, the KMV4 is a great piece of packaging, not taking up much more space than a parallel twin. Turn it 90 degrees, add belt or chain drive, and you’ve got the baddest cruiser on the street. This engine only requires some imagination to run in almost anything!

    As for the NASCAR/F1/Lemans comparison, it’s apples/oranges/bananas. C&D loved to do this sort of thing, if only so readers could justify their prejudices. None of those racers could do what the others could, so the exercise was just a bit of fun and an excuse to make some noise and serious speed.

  20. kneeslider says

    Couldn’t find the C&D issue but did find a similar article in Road & Track, January 1987. They, too, wanted to find the fastest closed course racing car and their contenders were the Holbert Racing Porsche 962 and the Hendrick Motorsport Chevy Monte Carlo. It was 720 hp SOHC fuel injected turbo flat six versus 640 hp single Holley pushrod V8. Verdict? Porsche 227 mph, Chevy 240 mph. Also interesting, remember, these are 1987 dollars, but, the Porsche cost was $325,000 versus the Chevy at $70,000. Cool!

    Reference material courtesy of The Kneeslider research library.

  21. Mark L says

    The Car and Driver comparison was in the late 80’s. The cars were a Porsche 962 with a Lemans’ tail, and the other car was Tim Richmond’s Winston cup car.

    The Porsche was at around 230 MPH, and the Nascar ran 242 and was still going. I remember the limit on the Nascar was the rear end gears. No one had ever ran one just flat out in a strait line before, and they said it would have gone another 10+ MPH faster with taller rear gears.

    I don’t remember a F1 car being part of the test.

    Pushrods are cool. If the rules don’t limit you on displacement, then you don’t have to Rev the motor to make power. Plus pushrods have some big advantages over DOHC/4V configurations.

    The biggest advantage is in overall height of the engine. With a cam in the block and rocker arms, you have a very short cylinder head height compared to anything with cams in the heads. You have some other advantages as well, mostly in drive complexity.

    They are both cool, and since HD killed Buell, and Victory apparently will never introduce a sportbike, (plus they appear headed south of the border) I am looking forward to Motus, and their claims that there will be a sportbike.

    I can’t wait!

    Mark L.

  22. kneeslider says

    The R&T article had the LeMans tail on the Porsche and Tim Richmond in the Chevy. Did they do comparison articles for both mags or is this the only one and I’m mis-remembering the open wheel car? I blame it on the beer. :-)

  23. says

    @ Jim – this motor runs a bevel trans, so the final drive is already chain. And to Brian’s comment in the video…the engine’s placement is already in the proper orientation. Guzzi riders agree.

    @ Rich_Too – agree about the limits of pushrods in terms of rpm, but Motus is developing a very different motor. Its initial intent is for the street, so the achilles heel version of limited rpm does not apply when other engine attributes are taken into consideration. In addition, look at some of the other comments here and around the web. As soon as some of these readers saw pushrods, they tuned right out and missed very intriguing design. And, are they also ignoring the ‘Vette’s recent success against some excellent hi-tech competition?

    “there is a reason that OHC engines can spin at ridiculously high rpms – and no MotoGP bike or F1 engine uses pushrods”

    Again, Motus’ initial intent is a streetbike, but since you mentioned racing, this motor is being considered for an Indy Race car application…

    Read the Race Engine Technology article. They discuss an Indy race option using a slightly modified Motus engine with a turbo. There are race series that allow force induction (thankfully). What is F1’s next move? They’ve already gone from v10’s to v8’s.

  24. christopher says

    i used to be one of those “techies” that didn’t appreciate anything unless it was at the bleeding edge and tuned to the absolute maximum potential. then i realized i drove on the street. and wasn’t going to make it near a track anytime soon. Motus’ engine looks fantastic. i hope it makes it to market. in two wheels, four, and hey why not three?

  25. Phoenix827 says

    I love the fact that its another American company trying do what Americans are famous for, innovating. The project looks very promising and the bike very interesting. I wish them all the success. Too bad I won’t be able to afford one. Would love to see that engine in a t-bucket hotrod with all the weight stripped. I bet it would scream.

  26. Mark L says

    Just as an interesting FYI, Nascar engines are considered to be the most highly developed racing engines in the entire world. This includes F1, MotoGP, etc. The number of engineers and the engine development budgets in Nascar would absolutely stagger you.

    I have been involved in some world level DOHV/4V engines, including Motorcycle engines, as well as owning and recently selling a former Rayhall Racing IRL Aurora V8 4.0 Liter DOHC engine that made 720 HP at 10,500 RPM, and weighed about 325 lbs.

    That engine cost $ 122,000 each when new. A current competitive Nascar engine makes about 775 hp, and will cost you about $ 35,000 new, and about $ 13,000 used.
    It will also turn 9,300 RPM all day long. That means held AT 9,300 RPM (redline) under full load for 500 miles.

    That is NOT something that a MotoGP, F1, or any other F-series engine can or will do. None of those engines can hold redline for more than a few minutes. Why? They are built to the rules for the class. Same as Nascar. The only difference is that F1, Etc. change the engine rules every so often. Nascar does not. It is only now, after nearly 50 years that Nascar is going to allow fuel injection.

    When the rules are kept the same for so long, you spend staggering amounts of money on everything you can to get that extra 3 HP. Metal Matrix pushrods? Check.
    6242 Ti valves, a given. DLC coated wrist pins. Yup.

    The really cool stuff like ceramics, ceramets, and intermetalics, (Look it up) are developed in response to rules. If your rules say this bore and this stroke are limits, and must use approved head castings, then why spend a zillion dollars for a ceramic valve, when an off-the-shelf Ti part will do?

    In the street, there are no rules other than the EPA and the public pocketbook. If you an make a powerplant cheaper and reliable enough with pushrods and steel valves, that meet your design criteria, for size, weight, performance, cost, etc. doesn’t that make more sense than artificially limiting yourself?

    If you are going racing in a class, build to those rules.

    If you want a 200 HP engine that you can build at an affordable cost, with future needs in mind, and there are no rules, then why start with artificial rules?

    No rules say DOHC/4V or Inline 4, or V5, or V2, so why not look spell out the actual requirements and wants, prioritize them, and then start working instead of limiting yourself to what everyone else does?

    They have the funding to develop their own engine and so why not?

    Being intimately involved in the Roehr Motorcycle Co, I know more than most the issues of building around an off-the-shelf engine. If Roehr had bottomless funds rather than just the million or so that they have spent, do you think that they would be using a V-Rod engine? Since the 1250SC was not built as a race bike and needed Major power, use a blower. Remember, no rules on the street except EPA.

    As far as Motus, I look forward to the bike, and wish them the best of luck!

    Mark L.
    Mark L.

  27. says

    Lots of advice on what Motus should or shouldn’t build, but one aspect is missing. When? When will all this happen? When will we see or hear a test bike? I know as well as anyone that building stuff takes lots of time. Do they have a projected release date?

  28. David/cigarrz says

    It’s the only water cooled cycle engine I have wanted to own. All I want is a crate motor I’ll build the bike I want.

  29. Ry_Trapp0 says

    @Rich_Too: Why does an engine need to spin high RPMs? There is more than one way to make power, and screaming RPMs aren’t the only way to do it. Diesels, for example, are fundamentally limited to about 6,800RPM or so max, because the burn rate of the fuel is so slow. Yet both the season points champion and the 24hrs of LeMans winner in the LeMans series in the LMP1 class has been a diesel powered car for the past 5 years. These cars are EASILY as technologically advanced as an F1 car, yet only make due with ~6,800RPMs max.
    Simply put, you overcome the limited RPMs by using the substantial torque advantage(an engine making 200HP @ 6,000RPM will always have more torque than the same 200HP @ 10,000RPM) to pull taller gears.

    Props to Motus and Katech for an absolutely fantastic engine, an a huge breath of fresh air for both the 2 wheeled and 4 wheeled industries. I believe I’m more excited to see what 4 wheeled projects this will find its way in than 2 wheeled! If this isn’t the perfect engine for a rock crawler, then I don’t know what is!

  30. says

    A very ambitious project indeed, I too started a motorcycle company, but decided to use (at least for the time being) tried and tested motors as a building block.

    It is great to see so many sides to motorcycling. I just got into Trials bikes, where a 50cc motor, and a small slender aluminum frame are all you want and need. What a contrast in philosophy. There is room for all and any rendition of the motorcycle. One thing is for sure, there are guys that can have fun hitting jumps on a 50cc pit bike, then have just as much fun riding later in the day on a 1600cc tourer. I wish the guys at Motus a long and wonderful adventure!!!!!

  31. zipidachimp says

    all i want is a 750cc v-rod engine in a lightweight frame. our current obsession with big engines is inexplicable. motus should try cloning the honda magna v-4, 750cc and turn it 90* if they want. honda even produced a similar engine to the motus configuration, remember the pacific coast 800? no marketing and no one bought it! good luck!

  32. Bjorn says

    I love the simplicity of this engine design and the idea that it is designed to be modified by the owner using tried and tested engine modification techniques.
    While many people want the maximum available horsepower out of the box, some are content with enough and others are enraptured by the idea that there are simple and (relatively) cheap modifications they can make to improve their motorcycle. As part of a continuing relationship with the machine you can improve/alter it over time. What a brilliant concept; it’s just like the machines of the past.
    I like the idea of a motorcycle you can keep for more than a few iterations of the product cycle; something like the old bevel drive Ducatis. Speaking of which; a Motus KMV4 engine would be a pretty good powerplant for a modern version of a Super Sport or Guzzi Le Mans.

  33. zlatzky says

    “BMW 160 horsepower, KMV4 161 horsepower. The BMW 6 makes a little less horsepower than the KMV4 and it has 6 cylinders, dual overhead cams and 4 valves per cylinder. The pushrod, 2 valve V4 does more. Advantage KMV4.”…. I think the BMW engine will provide more than 160 HP. I have read articles about that, and they say it will be around 180 HP, which, i think more likely.

  34. dan says

    This thing is a beast. Is it fuel efficient? That is all that matters. I had a 63 Ford F100 with a 289 in it and 3 on the tree and that thing got excellent gas mileage. Perhaps it is possible to get great mileage with this set up. We’ll see?!? With smooth mechanical operation and fuel delivery along with optimum head flow, it’s possible, however is this the most fuel efficient set up. That will go a long way in determining it’s usage for the average consumer.

  35. Kevin says

    Interesting discussion, but I feel some important aspects have been left uncovered in the whole F1/LeMans/Nascar/apples/oranges/bananas/lollypops discussion.

    1. So the Nascar is faster in a straight line, top-speed-wise. Has anyone other than Mark L considered gearing? Has anyone considered the gearing of the Porsche at all? If a 720 hp Porsche (probably with bags of torque over the Chevy, since the Porsche is force fed) with excellent streamlining will do 227 mph and an equally streamlined Monte Carlo look-a-like shell over a tubular frame with “only” 640 hp will do 240 mph, my guess is that the Porsche has shorter top end gearing. How did they compare acceleration-wise?

    2. So, a Nascar engine can sit at 9.300 rpm for 500 miles / two hours on end. So can my little Yamaha/Minarelli 125cc four stroke daily beater. In fact, mine has covered at least 7.500 miles at the 10.000 rpm red line so far and I’m not exactly maintaining it well (already missed two oil change intervals). I hit the rev limiter at 10.500 rpm at least 10 times a day streamlining behind faster traffic – I have to, it only does 90 mph at the limiter in top gear so going along with traffic on these European highways means full throttle in every gear, all the time, slipstreaming behind cars and SUVs doing at least 85. It has continuously sat at the red line for over an hour and a half once and didn’t miss a beat. And it still returns 80 mpg (US) / 95 mpg (Imp). Now that’s what impresses me, a little 4.000 dollar sporty bike with a single cilinder engine doing what the most advanced racing engines in the world do – and then some. Of course, the mass of the moving parts is way more beneficial to high rev abuse in such a dinky little engine compared to a big V8 and that’s where the engineering and manufacturing challenge lies with the latter… By the way, to put things in perspective: a Honda S2000 engine can do 9.000 rpm all day long and has a specific power output of 120 hp / litre… naturally aspirated and smog/noise legal.

    3. Why do we need 160 hp long distance tourers? Well, maybe not in the USA where the speed limit is often a measly 55 mph and a State Trooper with a laser gun sits behind every bridge pillar. But in Europe, traffic in the left lane is typically moving at 85 – 100 mph (as long as no-one is obstructing the flow of traffic on our three lane highways, that is). A Harley simply won’t cut it over here if you need to get somewhere in a relaxed state of mind. Different folks, different strokes maybe ; but geographical location makes a BIG difference to what’s appealing. Like a New Yorker would have different needs than someone living in Montana, let alone another country like India, Japan, Iceland, the UK or Italy. All very different needs and perspectives involved.

    4. This last point brings me back to four wheelers. In most countries outside of the US, high displacement is a major issue tax-wise. In Belgium for example, a 2.0 litre car would cost you around 450 dollars a year in road tax. A 350 small block V8 way over 2.000 dollar, verging on 2.500. That’s a large amount of money, and if you consider that a good 2.0 litre engine is more than likely in a lighter package and, when force fed correctly, can easily have the same power output as a 350 Chevy (400 hp from a streetable 2.0 is nothing major these days)… it’s an easy choice for most people there. In Italy, 2.0 litre has even been the limit for quite some time if you wanted to get your car insured for a reasonable amount – which brings me to another point: why would even an American choose a V6 Mustang over a Mustang GT? They only differ marginally in purchase price, maybe 100 bucks tops a month, so that’s not it. Answer: insurance rates. Anyone can afford to buy a car with a big displacement engine, but not everyone can afford to actually run it. And it’s the same with racing classes. Why did Porsche not just make a Nascar copycat if the Nascar engine was so much better? Rules and regulations. What if Porsche decided to let all of its European fine tuning loose on the Nascar engine? What if Chevy had decided to go the other way around and develop a small high output engine for endurance racing? We’ll never know, it’ll remain comparing apples to oranges.

    Is the Nascar engine fantastic? Yes! Is the Porsche engine fantastic? Why yes, it too! Is one better than the other? Given all circumstances: no!

    Race on sunday, sell on monday. We know Europeans can build exquisite V8’s (BMW, Mercedes, Ferrari) and we know American manufacturers can build very good low displacement engines (the Buick 3.8 V6 from the GNX, the Olds Quad4,…) but they never were the bulk sellers in the home market. So they both concentrate their racing efforts on what will sell the most during the week, being V8’s in the US and small four bangers and diesels everywhere else.

    So yes, it really is comparing apples to oranges, and the same goes for comparing the Motus (which I love, by the way!) with the BMW engine. Nobody here has riden either, so nobody knows which really will be the most enjoyable powerplant to their tastes and needs. There’s more to an engine than the specifications on paper.

    (Sorry for the long rant, but I’m just trying to cover all the bases.)

  36. Mark L says

    Hi Kevin,

    On # 1, the Porsche was not a gearing issue. The Porsche is/was a road course car, and had very substantial downforce, which results in aerodynamic drag. The Nascar is designed for running at a very high average speed in a crowd. 2 different types of racing, and the actual magazine comparison was meaningless other than to see how fast they could go.
    Those cars could never, and were never designed to race each other. but cars built to their same rules.

    2. I was specifically talking about top level racing engines that have been very well developed. AKA F1, MotoGP, Nascar, Etc. Street engines of any sort are developed fuel economy at low RPM and part throttle loads. If you took your S2000 engine and developed it for high RPM power with better port design, cams, valves, pistons, etc. It would not be limited to 9,000 RPM unless the rules mandated a max RPM level. It would be turning 10,000+ RPM. You build and develop the engines to the rules for your class. MotoGP and F1 don’t run 500 mile races at top speed all the time, so they are not developed for that. They also change the engine rules every year or two, and that limits the development of the engine.

    Nascar mandates a max bore and max stroke, which the linear piston speed limits RPM. They also rule on which head casting that you can use, etc.

    Ferrari or Ducati only support about 6 bikes and cars for each season, and the engine rules are only fixed for a few years at most. Think that gets a lot of development time and resources compared to a series that will support 500+ cars with rules that will be fixed for 10+ years?

    Nascar will have potentially 500+ cars in all series that run the same rules that only change about every 10 years. That is why the development is so much higher in a Nascar engine. It is all rules driven.

    IRL mandates 10,500 RPM as the limit by the way.

    No rules on the street, so build what you want!

    Mark L.

  37. Tom says

    A lot of motorcycle technology is driven by displacement laws (street use): restricted licensing, punishing taxes, outright bans. Most of the rest of the world has to get what they can out of arbitrarily constrained engine sizes. A prime example is the 250cc, four cylinder, DOHC bikes they offer in Japan.

    Here in America we are not so restricted. Despite endless motorcycle magazine _displacement_ comparisons, what’s really important to American riders is how much you pay for it versus what it can do. In comparison to that Japanese 250-four, we could have a 650cc OHV single: smaller, lighter, much less expensive to manufacture, better fuel economy AND more power.

    Low tech? Smart tech!

  38. JohninVT says

    European commenters who think we have 55mph speed limits in the US haven’t been here since the 70’s. We have 75mph limits in many places and true highway speeds in the neighborhood of 80-90mph for hundreds of miles on end. The US is a big place. You could cross 7 or 8 European borders in the same distance it takes to cross Texas. Large displacement touring bikes make perfect sense when you travel at high sustained speeds and cross 10,000ft high mountains two-up, loaded with gear.

    One potentially negative aspect of the Motus is going to be rotational inertia. With dual counter-balancers and 1600cc’s of piston travelling thousands of feet per minute, the bike is not going to want to turn. I’m really curious to see what the frame geometry looks like. I own a Guzzi 1200 Sport and saying that it is supremely stable at speed is just another way of explaining that it takes a lot of effort to turn when you’re riding hard.

    I have ignored the Motus because I find it hard to believe anyone has enough moeny to absorb the losses necessary to bring an entirely new machine to market. However, after having the hair on my neck stand up listening to the engine spin on the dyno…I really wish them success and am eager to see future developments.

  39. pabsyboots says

    great wite up and opinion ! the motor has style is different should play up its small block roots
    david is right this makes a great crate motor

  40. Kevin says

    Hello Mark,

    That is quite right, however I do not agree that there are no rules on the street. There is a rule: it has to sell, be viable, and that depends on a lot of variables – not in the least marketing the product, and that’s where racing steps in, but more on that later. Legislature is a big factor. I’ve quite often noticed that the average American internaut either simply doesn’t get why other people would waste their time on anything less than a big V8, or they just start throwing insults when somebody steps up to defend their choice for something different. Many don’t see the bigger picture and that’s a shame. But then again, they’re being force fed on an all-American diet from every angle so it’s not difficult to comprehend why they can’t relate.
    That being said, there is certainly merit to the bigger is better adagio but it’s appeal is very limited in the worldwide market. If a small company is going to survive, it’d better come up with some alternative or sales will not even cover the startup cost, let alone be profitable. Look at what GM, Mopar and Ford have gone throught the past couple of years and those are global companies with strong oversea branches.

    In my view, most racing classes are fenced off by rules and regulations to prevent intruders from foreign markets penetrating into what is a formidable instrument for selling engine concepts to the masses. For example, at Le Mans, the diesel engines are allowed to be force fed and the petrol engines aren’t. Why? Because over half of the cars sold in Western Europe are turbo diesels by now and the diesel pushing manufacturers like Audi and Peugeot (who bring in the money for the event, ultimately) have to look good on the track.

    Now, back on the main topic: I just thought of something. I have owned an Alfa Romeo 2.5 V6, a BMW 2.5 straight 6 and a Saab 900 2.0 Turbo four. All three engines with very similar characteristics on paper: around 180-195 hp, approx. 250-265 Nm torque, similar rev range. All performed more or less the same in terms of acceleration and top speed as well, since the weight of the cars was within a couple of dozen kilo’s apart. Yet all three were miles apart in driving experience. Stock for stock, the Saab may be just as flexible and fast as the other two, even faster for in gear acceleration, but it’s a coarse engine – a bit brutal even. The BMW was silky smooth with a good top end but ultimately quite boring, it never made the hairs on the back of your hand stand up. It was too perfect and lacked… soul. The Alfa would constantly edge the driver on, sound heavenly and reacted to every input like a puppy to a meat covered tennis ball. It just begged to be grabbed by the colar and beaten to a pulp, singing elegantly in pain all the way through and then coming back for more. Real character in that one.

    My guess is the Motus V4 and BMW slant six will do the same trick: comparable performance, undeniably different ways of doing it. Some will like the character of the Motus more, others that of the BMW. But to say one will be better than the other, or one is superior in concept and puts question marks over the existential reason of the other is a bit far fetched in my opinion. Both engineering teams are convinced they have come up with the best solution, in the end the customer decides for him- or herself.

    There is a big parallel between the KMV4 and the BMW six: they’re both scaled down versions of a car engine. Motus is open about this, but take a closer look at the BMW engine and it’s clear as rain they too went to the car department for inspiration: single throttle body, plenum chamber induction, no balance shafts, hollow cams with pressed on lobes… Could this be the start of a new trend, to lure more car folk over to motorcycling? Or will it work the other way around, selling the “right” cars in their view to motorcyclists?

  41. John McDowell says

    So I come to this dicussion kind of late! What are the horsepower / torque specs
    for a Yamaha V-Max? I think they have been around for 20 years or more. Same deal, make it, then let word of mouth sell it.

  42. says

    Awesome, I want 3 of them to make a V12 Morgan 3 wheeler . There is allot to be said for the simplicity for push rod motors. With new high tech materials you can get most of the problems with the valve-train all but eliminated ( carbon push rods and rockers ? )

  43. says

    @ JohninVt –

    I’ve been riding a Guzzi V11 Sport since 2002 and it turns great, in sweepers & tighter curves. In fact, it turns so well that I’ve thought the mass of the flywheel (in that orientation) helps the bike turn easier. i.e. a body in motion wants to stay in motion so, a flywheel spinning around in an engine that has a transverse crank will resist changing direction.

    There are many other factors in 2-wheeled engine/chassis dynamics, but it seems an engine with a longitudinal crank helps in turning (someone correct me if I’m wrong). This layout isn’t used to a large extent due to the power loss to the final drive. (The engineers’ decision-making to overcome the mechanical/vehicle compromises makes for quality conversation)

    Motus’ 90-degree switch in their gearbox should not impact the advantage of the rotating mass in the engine, and with its displacement and torque, the power losses are not going to be missed.

    James Parker’s Eller Industries sportbike design called for a v-twin with a longitudinal crank & chain drive. It would be interesting to know if he chose desmo valves in that design, in part, to make up for the power loss to the final drive.

  44. Paulinator says

    This is a good read. I love the concept. Push-rod V with (relatively) big displacement. All this simplicity speaks volumes. It should have 6 holes and 60 degree angle, however. Hey? What about the Dodge/Trenton V6?

  45. mxs says


    as you can see from the comments, it’s never a good idea to get carried away by throwing in cross platform comparison which only proves that apples are better than oranges …. under certain uncontrolled environment.

    Now, back to the Motus concept. I never said that I don’t admire the technology they are researching, or that an engine has to be based on I-4 high revving, multivalve head … on contrary. All I am disputing is a need for 1600cc sport touring bike. Even VFR1200 is overkill in my opinion (how many sport tourers really rode the wheels off VFR800? I dare to say that none when used off track). What do you need the monstrous power for? A spirited ride or track time on a sport TOURING bike??? I just don’t get it.

    It seems like a lot of things is being done only because they can be done, not because they can yield a better result at the end. Which is fine if you do not need a sufficient customer base, keeping you in the business.

  46. Dr Robert Harms says

    zipidachimp 07.07.10 at 2:39 am
    “second thought, a yanmar diesel in a bike!!!”


    Like the 38′ Ariel with Yanmar L10AE in my garage ?

  47. todd says

    To me, anything over 100HP (or even less) is more than I can utilize or make the most of. Though I live in the USA I don’t live in an area with wide open interstates or any other roads that allow much more than 80mph, much less through all the mountain/canyon corners that make up a major portion of my 64 mile commute. For this reason I choose bikes that are smaller, lighter, more fun. I’m able to run a road faster on a bike that has a 110 rear tire vs. one that has a 190. I also go through a rear tire every 4 months or so and replacing the 110 is much easier to do on a regular basis than the ridiculous cost of the 190. Some people like smaller bikes just because.

    Since I don’t race and I don’t choose a bike I want based on specs for a bike like this, for me, it ultimately comes down to a few intangibles like: Can I afford it? Does it look cool? Does it sound great? Do I like the company? Is it reliable? Does it get good mileage? Is it light and easy to flick around? So far, for the Motus I can say “no, I don’t know yet, YES, sure, hmm…” For my existing bikes it’s “yes” on all accounts.

    I do like this engine and I do like what this company is trying to do in the face of extreme competition – already comparing it to BMW’s latest and greatest. Will I buy one? Likely not when I can get the just-as-capable for me, aforementioned PC800 or R100RT for much less.


  48. kink says

    Doesnt honda already make a bike close to this design.? The ST 1100 and the newer ST 1300 injected version.

  49. Jim Stumo says

    I am sure someone has already suggested it but here goes my vote. Please develop an 800 v-twin and a 400 single to go with the big engine. Then Motus can be a full line manufacturer like no one else in the US has been for quite a while.

  50. says

    another reference to a Honda Pacific Coast 800? Unreal.

    todd – we understand you are fortunate to ride in some of the best riding this planet has to offer. That affords you to buy any number of bikes for any number of moods. The majority of others will need to ride great distance to get to the enjoyable roads. The v4 rumbling along will make the straight roads to those destinations enjoyable too. Not so much on the small bikes.

    Jim Stumo – agree. How about an 800-850cc twin (optional Rotrex supercharger) ? The front of the engine block could be updated to include a swingarm pivot for a front-end like the Britten or the Aprilia FV2 concept. Short wheelbase. Lightweight. Funky & functional.

  51. jp says

    I’m gonna throw my vote in for the crate motor. There are a few applications I’d love to see this motor in, aside from my dream trellis-framed cafe/standard. It’d be even more compelling (albeit unlikely) if it could hit the same price point as an S&S crate motor.

    1. A tilting reverse trike
    2. A smart car motor retrofit
    3. An airboat

    And why not?

  52. says

    From the, “For what its worth department”, I’ll summarize what I’ve read. Everyone has an idea for a different size motor that should be built, a different style of bike that should house this powerplant from cafe racer to chopper to (reverse trike?), all sorts of configurations, V-twins, single, six cylinders, motor turned 90 degrees, etc, too much power, not enough power (that would be me till I read their webpage), not the right size to fit the confines of a racing class, lose the pushrods, how many and what type of model variety should be produced and finally what it or they should cost.

    Conclusion? Motus dreamed up the concept. Motus designed the motor and the frame. Motus built the prototypes, the webpage, acheived a running engine with awesome sound, and is formulating their plans for the future. Do they really need all this advice? Looks to me like they’ve done their homework and are way ahead of us here in forum-land.

  53. joe says

    The benchmark for a top motorcycle engine is the Suzuki Hayabusa.This engine has big horsepower ,lots of torque and delivers smooth, linear power throughout the rev range,plus its economical on fuel. For an engine that came out in 1999, it still has few if any equal, BMW included. As the old saying goes,the proof of the pudding is in the taste. When all the high tech hype and performance figures are put to a real life road test,only then will we see how good the product is.

  54. says

    JP, Why not? I can’t think of anyone on earth in their right mind that would want to waste this motor to own or drive a 200 HP Smart car. That’s the fastest way to get betwwen two points and the final point is the hospital! It would be interesting to see someone try to drive it during intermission at the weekly demolition derby though.

    Airboat? Ok, I’ll give you that one!

  55. Jody says

    Of course we can compare apples to oranges! After all, we are in the market for FRUIT!

    …and yes it does sound awesome…just wait ’til it has a set of slip-ons!

    Motorcycles, like many things in life, are highly individualistic things. If you like it, buy it. If not, then don’t! It’s that simple.

    Mule- Love your trackers!

  56. says

    Mule – “everyone” on this forum has suggested they do this or that? There are numerous people who agree with what Motus is doing, long before their engine sound came out this week.

    Suggestions about future bikes can be called “enthusiasm” for what Motus is doing now and in the future. Besides, the conversation rolled around to various topics on a few occassions. Big deal, but good for Motus & the ‘ Slider.

    Even the author of the Race Engine Technology article started his article with a letter to an Indy Car chassis developer recommending that he should adapt the Motus engine for his Indy Car. Enthusiasm.

    Motus’ decisions have been spot on imo. The sport touring market needs a hotrod, and wow, are they methodically making impressive progress to fill that gap.

    The expanded sportbike market that started years ago means that a good % of riders are not necessarily going to migrate to a hog in 3-5+ years. They’ll want something more. Motus is positioned to be a very special part of the growing Sport Touring segment if they can get their price within a stretch. Meanwhile, Harley tries to figure out what to do with the Revo platform.

  57. wade says

    safely,no one threw rocks at me and will return the favor to each. and i promised myself i would not address any comment submitted by all of you fine motorcycle enthusiasts who display real motor knowledge and love of machines beyond the average gearhead. i will say, less is more; simplicity rules in machine design as well as art, or a host of useful design concepts from houses to choppers. myself, for the last 5 years,am completely burnt out on the so-called one of a kind scrap that has occupied the motorcycling realm for more than 12 years now. so disgusted that i gave away 2 choppers that i built while keeping my old “hot rod project” to myself and have entertained scooters and , GASP, chinese small displacement motorcycles for the sheer lack of status and “feathered cock” mental level that has rot the sheer joy of riding a motorcycle. with that said, i am very excited by the efforts of Motus and this design effort displayed. in the presented article thrust into each of our motorcycle world,mr. Kneeslider has said it all. of course there is uproar, whether pro or con. that, in its self says a lot for the featured manufacturer alone. and says miles and miles for the motorhead at the helm

  58. Dawg says

    Whatever happens with that engine and the bike, just the sound of that thing on the dyno must have made them really proud of their achievement. Looks like a really serious team that will get results.

  59. Rob says

    Leave the compression as is, add a low pressure turbo. Bit of nitros for the weekends… Should be strong enough to handle that standard.

    Anyway when’s Triumph building me a 1600 triple cafe racer?

  60. wade says

    already, this thing has stirred emotions in the motorcycle market. at least in the level of reach of this forum. what an accomplishment ! a stir as it may in the very world that we LIVE.

  61. Nicolas says

    It really doesn’t matter if the engine is too big or too small, too many cylinders or not enough, or how it performs compared to a beamer or a busa.
    The people at Motus have a vision, they had the courage, the good fortune and the balls to make it happen, to translate their idea into a real machine, and only the market will tell if this vision has a commercial future, but certainly not any random anonymous blogger on the web.
    Good luck to you guys.

  62. jp says

    Mule: sanity isn’t something I claim to have a lot of… I just don’t have the time or equipment yet to put my rambling ideas into metal :) You could substitute the Smart with a classic Mini Cooper or any number of motorcycle-engined Lotus/Caterham replicars… The Smart was just the first thing to pop into my head as one had just driven by.

    I was thinking of the Motus sort of like the small block Chevy… You can find one wedged into nearly any vehicle imagineable. While we’re at it how about a dry-sump conversion, perhaps suitable for light aircraft? :)

  63. JP says

    the Motus is a simpler basic design but very similar layout to the Honda ST motor.
    I like the airplane usage thought from above. Or a small car. (Scat made a V4 based on the sbChevy used in offroad racing, and midgets)
    A Motus in a mid-engined roadster or a Miata …hmmm.
    Or in an old Opal GT…….

  64. says

    JP, I had a Mini-S with a Dinan kit. It ended up at about 215hp. It was a blast but I think I really could have used about 275 to be totally content. So this new motor for the money wouldn’t have gotten me anything I couldn’t buy and bolt into/onto what was already fiited into my stock Mini.

    However, I would love to build a scaled down, motorcycle/belly-tank, 4 wheeled Bonneville car and this motor would be perfect.

    In the 60’s Mickey Thompson went to Bonneville with a couple cars and a truckload of engines. He would get a record, swap the motor and go out and get another record. I remember reading that he cut up a bunch of V-8’s into different configurations. Remove the two front cyls…V-6. Remove the front 4 cyls….V-4. Remove one bank…inline 4. Cut that bank in half…..Inline twin! The only horsepower number I can remember was the inline twin, supercharged made 257hp! He set a record with that for 850cc or 1000cc or something like that. Anything is possible!

  65. Thom says

    I am extremely enthused that Motus is progressing so well with their design, and I wish them the best. I personally would not be able to buy such a bike, and I feel it’s overkill for the average rider, but it is well-designed and unique. Should this engine ever be offered as a crate engine, I’d love to build a small, rear wheel drive street car with it, a la the AE86, but I’ll stick with smaller stuff when I want to be on two wheels.

  66. jp says

    Hmm there are multiple JP’s… I’m the lowercase one :)

    Just to clarify, I was referring to the original BMC/Austin Mini, not the BMW Mini (which is too big and heavy for a Motus swap to make sense really).

    Bellytank sounds neat, chuck off one of the rear wheels and make a street legal streamliner commuter vehicle perhaps with a canopy for weather protection. Just be wary of tractor trailers!

  67. Kenny says

    I’m more curious about finishing the design than comparing it to any other engines. There’s plenty of V4 platforms out there at the moment if you want to compare it to something, Vmax is obviously the closest followed by the VFR1200, then the new aprilia mill (or mille ;-P) and the ducati D16rr.

    Will Motus stick with that transverse gearbox design, (which I personally think looks hideous). I can’t think of any longitudinal engine layouts that have used a chain/belt final drive.
    How are they gonna route the rads and plumbing? The cooling layout looks very compact.
    More than anything I look forward to future developments. And hopefully a fire spitting cafe racer with that sound.

  68. Steve Snelling says

    The Motus Engine looks great and probably sounds even better, but the longitudinal mounted crankshaft configuration may cause a large amount of torque reaction transmitted to the chassis. Imagine getting on the gas exiting a corner and having to compensate for this torque reaction base on wheather you are turning left or right. Probably not a huge problem on a touring rig, but mayhem on a track bike. This is the reason the MotoCzysz engine had counter-rotating crankshafts.

  69. Dawg says

    So that’s what happens to old fuel tanks! – I had no idea! Those belly tank racers are really cool. Motus need to capture the kind of enthusiasm and spirit that made guys build speedsters out of gas tanks! Lets hope the salt flats resound to some new music!

  70. biggyfries says

    I am excited at the prospect of a large, understressed, American-made motorcycle that is not looking to be ‘outlaw oriented’, as with Harley, Victory, and others. I want it to be immensely powerful and indestructable, and I hope they make the seat height adjustable as Triumph and BMW have done. I’m a tall guy and know there is a market for a tall motorcycle.

    On displacement/horsepower/torque–I say there is no upper limit. I want plenty of HP because I love to go over mountain passes as if they are molehills. I love power enough to zap three 18-wheelers at a time, and it would be cool if downshifting were unnecessary. I also like to have a bike that handles like a sport bike. I don’t see why the Motus can’t be that kind of motorcycle, and if so, I would own one at the earliest opportunity.

    Motorcycles of this type exist, I’m thinking of the Hayabusa and the little-loved Kawasaki ZZR-1200 (–what a motor!!). If they had a seat height of around 34 inches and handlebar height that didn’t require a crouch, I’d be a happy man. If it made huge torque and revved less than 10,000 rpm, no problem. If it handled like a full-on sportbike, and were made in the USA, wouldn’t that be a compelling choice even in the current market?

  71. Steve says

    This is a screenshot of an engine design. YEARS, MILLIONS, and so much PAIN away from production.