Suzuki MotoGP Prototype Spied In Japan Leaves Many Questions Unanswered

That Suzuki is working on a MotoGP prototype for a return to the premier class at some point in the future - 2014 is the date Suzuki staff have referred to officially in all their communication - is well-known. There have been several reports of the bike being tested, but no real photos or information on the bike. Until yesterday.

On Tuesday, respected US publication Cycle World published spy photos of the brand new Suzuki on its website, taken while testing at Sugo. Even better, along with the photos, they published a detailed technical analysis by Kevin Cameron, the magazine's technical editor and probably the leading authority on motorcycle racing technology. The bike, according to both Cameron's analysis and Cycle World's sources, is an inline 4, and not the V4 that Suzuki had previously hinted at. The engine is inclined forwards considerably, Cameron suggesting that it could be by as much as 30°. The engine is just visible in one photo, and is clearly inclined significantly, certainly more than the Yamaha M1 engine used in their 800cc bike, which they displayed at Valencia. The advantage of using an inline 4 is improved weight distribution, with the space behind the engine (where the rear cylinder bank would be on a V4) freed up so that the fuel tank can be located there.

Based on the two exhausts visible on the right-hand side of the bike, as well as reports from persons present at the scene, Cameron also deduces that the engine does not use the normal "screamer" firing order as commonly found in inline fours such as Suzuki's own GSX-R1000, BMW's S1000RR or Kawasaki's ZX-10R. The two separate exhausts suggest a "long bang" configuration, similar to that used by Yamaha's M1 MotoGP bike and YZF-R1 sportsbike, in which the crank pins are spaced at 90° angles two each other.

The most interesting piece of speculation by Cameron concerns the electronics. Cameron writes: "in one of the cornering photos, [the rider] has the throttle pinned, suggesting advanced electronics in use." The intriguing possibility is that Suzuki may have elected to drop Mitsubishi, who supplied electronics throughout the Japanese factory's period in MotoGP, and are testing another system. The technical partner stickers that appear on the bike show oil company Motul, spark plug maker NGK, chain supplier RK, tire manufacturer and data recording supplier 2D. A sticker bearing the name Mitsubishi is absent from the bike.

The technical partner stickers themselves beg the question of why they are there in the first place. Though Suzuki have made no secret of their MotoGP program, it is still a little way off being ready for public consumption. So why they would add the sponsor stickers to what is clearly a development prototype is rather puzzling. Why go to all that effort?

Unless they were expecting photos of the bike to appear, that is. The spy photos obtained by Cycle World are of the highest quality, clearly having been taken by a professional photographer using top-of-the-range equipment, including a large zoom lens. Though Sugo is a public track, when rented out for a private test to a manufacturer, photographers lugging 500mm lenses around are generally shooed roughly away. There is clearly a benefit to Suzuki to have spy shots of their bikes appear in the media, as it raises the profile of Suzuki's racing program, and generates a lot of publicity. 

So perhaps the photos were leaked, or if not leaked, then a blind eye turned to the presence of somebody taking photos of something they ostensibly shouldn't be looking at. Allowing spy shots to be released to the press generates interst in the program, and could perhaps be a sign that it is further along than previously announced. Though the official press release announcing Suzuki's withdrawal from MotoGP stated that the goal was to return in 2014, once source close to Suzuki recently hinted to that a 2013 return was not beyond the bounds of possibility.

For the full and detailed analysis of the spy shots of the Suzuki MotoGP machine, we heartily recommend that readers head over to the article on Cycle World and ponder Kevin Cameron's thoughts on the matter.

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What are the chances that what they are doing is developing a CRT entrant? There was room for more than one factory built 2-stroke 500, there should be more than enough room for more than one factory built CRT.

As I understand it, all they have to do to qualify as a CRT is have engine "based" on a production engine and be willing to sell them for a set sum (40,000eu?). Since we have no idea what a 2014 GSXR engine looks like, this seems like a very good possibility.

I am totally behind the idea of more of the GP bike being sold rather than leased. It makes the engineers engineers not part swap managers.

I could become a Suzuki fan again. My first four bikes were Suzukis, before the FZ 750 made me a Yamaha fan ever since. Yeah I know a chassis from hell but an engine to die for.

There is nothing in the CRT rules about having to use a production-based powerplant, just that you have to be willing to give it up for a paltry fee (compared with the development/production costs).

So, in theory, Suzuki could develop this full prototype bike, flog it to a private team, and it could be run as a CRT. Although the sheer cost of making these factory bikes means that will never happen, I'd actually like to see the series go back down this 'production racebike' route, recreating the model that Yamaha and Suzuki used to use.

You stopped being a Suzuki fan? Shame on you! ;P

Reading the rulebook there seems to be a contradiction as to who decides what team gets CRT status.

In short, the CRT machine allowances are simple; bigger tank, different size brakes for 2012. And CRTs get to use more engines. That's it. Nothing about production-based status, nothing about having to be sold and not leased. It is perfectly acceptable for a factory to build a CRT.

The FIM rulebook available online states:

- The CRT status is approved by unanimous decision of the GPC in order to ensure fair competition, and based on the same consideration it can be withdrawn at any time by a majority decision of the GPC members.

But later, it states:

- CRT’s are subject to the Claiming Rule (Article 2.2.2) and must
not represent any MSMA manufacturer, as defined solely by a
GPC majority decision.

Both bits of language are in Section 2.2.1

Unanimous and majority mean a world of difference in GPC decisions. Unanimous means that the MSMA - the manufacturers, Honda, Yamaha, Ducati - can veto any application for CRT status if they think it's a thinly-veiled factory effort, because the MSMA has a seat on the GPC. Majority means the factories lose any contested vote, because they have one seat, DORNA has one, and DORNA chairs the commission and casts any tie-breaking vote.

That's what is in black and white in the rulebook. If I'm wrong, someone correct me and point to where I'm wrong, please. If I'm reading something incorrectly, let me know.

A+ for the homework

It seems very unlikely then that Suzuki would be considering entering this bike as anything other than a full factory ride.

If for anything else, even if they got CRT status, if they really poured a lot of money and R&D into the engine, then why would they risk handing it over to another factory for a nominal price?

I really hope they come back next year.

Q: "If for anything else, even if they got CRT status, if they really poured a lot of money and R&D into the engine, then why would they risk handing it over to another factory for a nominal price?"

A: they wouldn't. this bike is DOA. why build a bespoke engine only to saddle it with a control ECU and have limits placed on it's development...? even if they can sell it for the proposed $1 million cap, when time comes for pen to meet paper, what person who knows anything about anything, is going to shell out that kind of coin given suzuki's history...? despite off and on rumors, observe how satellite suzuki's never materialized in a decade of 4-strokes.

re: "I really hope they come back next year"

i really hope they stay away. you'd think they'd have their fill of doing harm to rider's careers...? and compromising the image of grandprix...?

What does "must not represent any MSMA manufacturer" mean? There is currently a Honda engine running in the class. Does it mean that a team run by an MSMA member cannot run a CRT machine.

That's a pretty close interpretation, but here's how I understand the CRT rules will be interpreted and applied, from talking to various people involved.

First and foremost CRT = Claiming Rule TEAM. The entry of the team is what is assessed by the GPC. They decide whether this is a team being entered by a factory (which is what is meant by "representing an MSMA manufacturer") or an independent team. In 99% of the cases, that is pretty clear cut - it's more confusing in WSBK, for example, where the Ten Kate Honda team is a private team with strong factory backing - and so the entry is easy to judge. The machinery being used is not necessarily relevant at that time. The question to be asked by the GPC is "will this bike be leased or bought?" If it's leased, they will reject the application.

This leads on to the question of machinery. The ART bikes are a perfect example. Those bikes are being built and sold by Aprilia to be raced in MotoGP. The factory has a lot of involvement, but they have been sold, and not leased, to the teams. They are the first of the production racers that the FIM and Dorna have been pushing for for several years now. So if Suzuki were to build this new GSX-RR 1000 (for want of a better name) and sell it to private teams, they could enter as CRT teams and race that bike, with support from Suzuki. However, if Crescent Suzuki were to return with full backing from Suzuki in Japan, then they would only be accepted as a factory entry, and not be granted CRT status.

And the rules you quote raise an interesting point. The phrase "representing an MSMA manufacturer" has a hidden loophole. Right now, Aprilia, BMW and - yes - Suzuki are not members of the MSMA, as they don't have factory entries in MotoGP ...

So the "purchasing the bike" requirement is something that the GPC would require from any team asking for CRT status, but it's not written in the FIM rulebook. Is that correct, David?

I am not even sure that purchasing is a hard and fast requirement, but it is taken as an article of faith. It is basically about who has control of the bike; in the satellite teams, the crew can do nothing except strip and reassemble. They even need to get permission from the factories if they want to switch suspension manufacturers. The CRTs have control over the bike, they can do what they want to it. That's the issue summarized in brief.

Thanks. That does answer the questions I had surrounding the CRT regulations.

I completely understand the intent of the regulations, and I really don't have any issue with the intent - I enjoyed watching WSBK at Laguna just as much as I enjoy watching MotoGP there nowadays. It wouldn't bother me at all to watch MotoGP bikes with proddie engines and a "mere" 205 horsepower.

I do have deep concerns about setting up two sets of rules - especially rules that aren't clearly defined - and playing one group against the other. Pick a set of rules, and whatever they are, let the best builder/tuner/rider combination win.

I wonder if Suzuki are playing with a narrow-angle V arrangement similar to VW's VR layout. A narrow angle V arrangement reduces the width of the engine, but still allows for all exhaust ports to exit from the same side of the engine block. The two rearward cylinders could be paired in one header, and the two forward cylinders could be paired in a second header, but unlike a traditional V exhaust layout, all exhaust ports would face towards the front wheel. The distance between the cylinder banks and the intended end point of the exhaust system is not uniform; therefore, 4-into-2 could be used to provide more accurate tuning.

We have an engine that appears to be inline with a V-4 exhaust layout. Screams VR to me, but I'm not a professional engineer.

Didn't Suzuki say they wanted to stick with a V4 a few months ago?

I think you could be right, I suggested the possibility of Ducati going to a VR layout a month ago when Audi bought Ducati. I hope you are right in the possiblity of another CRT factory effort.

I almost completely forgot. Isn't/Wasn't Suzuki involved in a technical partnership with VW?

I know the relationship was strained from the start, but VW's investment in Suzuki could make a VR arrangement even more plausible, imo.

The VR arrangement (!) heavily compromises the inlet and exhaust ports, so I doubt it would be suitable for MotoGP.
Suzuki spent a lot of dough early in the 990 era widening the cylinder angle of their initially very narrow (but still 60-ish if memory serves) angle V4 because the inlet ports were being restricted.

If their bike is available for sale then technically it could be a CRT. There's nothing in CRT that says the engine MUST be production based.

Those breathing problems would explain the radical forward incline alleged by Kevin Cameron

Just leaning your motor forward so the port is more vertical does not improve breathing. It's the angle of the port relative to the valve which makes the difference.

The conventional VR is compromised because the inlet ports for the forward bank of cylinders have to flow past the rear bank heads (getting heated up along the way), and vice versa for the exhausts on the rear bank (heating up the front heads).

It's a design compromise that works very well in VW's various automotive applications including the Bugatti, but none have high specific power outputs and most are supercharged, which is an easy way to mask various breathing problems.

Maybe you could have the ports coming in independently in different parts of the head but the cams are usually in the way (and in MotoGP, the pneumatics). As much as I'd love to see something unusual like that, racing is these days ultra-conservative and I can't see an un-supercharged VR engine making 280hp/litre anyhow.

By the way, the VR concept claimed by VW to be their own was produced in various incarnations by Lancia as early as the 1920's.

This... my friends, is EXACTLY what makes this site so valuable. A perfect example of the pearls of wisdom that the comments section can be. Thank you greatly for the edification and taking the time to share your wisdom!

some prototype W 12's made for racing............... 4 cams per bank, 2 sets of headers per bank and inlet ports/runners, between the cams in the centre of the head........................

AFIK they were never tested in a car ( politics ). A bloody packaging nightmare . Think heat.............

Tilting the engine forward allows the intake air to make a less severe 'U-turn' as it travels through the airbox and into the backside of the engine. Furthermore, tilting the engine forward gives a bit more room to design a complex intake system, and alter the port/valve angle and airflow.

'Conventional' VR engines do not have port overlap b/c conventional VR engines are only 2-valves per cylinder with paired exhaust valves. Rather than commit a great deal of money to development and production of intake components, VW simply played around with the cams until performance was equalized across all revs for all cylinders. It was cheap.

Specific hp rose considerably when VW moved to 4-valves per cylinder (despite port overlap) and variable cam timing. When VW designed a proper intake and exhaust systems for the W12 Nardo engine (two VR6s), VW achieved 100hp/liter. Unfortunately, twin independent variable-length intake and exhaust systems are not cost effective for production cars. Turbocharging was adopted instead b/c it offers better bang for buck.

The complicated intake and exhaust systems required to make naturally-aspirated VR engines work are commonplace in racing. Most of the manufacturers already have twin independent exhausts to handle front and rear cylinder banks. I'd wager that the V4 teams also have twin independent intake systems.

Heat transfer is a problem, but it's a problem in every engine. Doesn't mean Suzuki is using a VR engine, but most of the complaints you've leveled pertain to the production market. MotoGP isn't production racing, not yet anyway.

And I think they ended up with about 220bhp or somesuch out of it. I think they could obtain a similar output to the ART if they wanted to race in GP today.

They closed up the V angle to about 15deg and having the banks share an inlet cam while having independent exhaust cams (Hence the 'Z' configuration). They got around the heat issue by running the inlet tracts between the cams, for a very minimal inlet angle. Add to this contra-rotating crankshafts (2 cranks end to end rotating opposite directions), and longitudinal mounting, I thinks its one of the most fascinating modern engine (and overall bike) designs there is.

This is by now completely off topic, because as much as I'd love to see something different I seriously doubt any major manufacturer would be brave enough. But it's turned into an interesting discussion, at least to me.

Happy to respect your opinion but generally disagree. :-)
Doesn't your 'U-turn' principle infer something approximating laminar flow, which only happens inside the port? I thought the objective of an airbox was to provide a large volume of fairly still air (if possible at positive pressure via ram air) from which the inlets draw. If you follow your theory to the ultimate conclusion, inlet ports should be on the front of the engine with the flow coming in the nose of the fairing and straight into the inlet port, but they don't. Conservatism? Maybe, or maybe all those clever engineers in Honda, Yamaha and Ducati do actually know more than a few keyboard warriors like us? :-)

As for the rest, by "conventional" VR I meant a VR as in the way VW does it - a single head with all the inlet ports on one side and all the exhausts on the other. Having now looked into how VW did it a bit I can see how you might have taken my comments differently. I see now that VW's 2-v VR heads were REALLY shitty, whereas their 4-v VR heads were only fairly shitty (while being perfectly good for their low performance purpose). 100hp/lt is not even worth talking about, even production motorcycles had that by the end of the 70's. Even the Veyron (with 4 turbos) only achieves 125hp/lt, so lets ignore VW technology - with or without variable inlet/exhaust port length - as being strictly for the taxis. :-)

The proposed Horex VR6 is perhaps closest to what I was describing as a decent "conventional" VR motor. It is 3 valves per cylinder and a triple cam head, but the centre cam operates both the rear bank exhausts and the front bank inlets. Unlike VW, at least there's no rockers, so the concept might be able to be made to rev a bit. But you still have the inherent problem of compromised port geometry and heat transfer issues significantly worse than a conventional I4 or V4 layout.

So on to Sideswipe's brilliant raising of the Csysz. What an amazing machine, I'd totally forgotten about it. It launched with great fanfare but at the time i could never work out the point of it. It was basically two slightly offset parallel twins with contra-rotating cranks. It sort of fizzled out and morphed into an electric bike, predictably winning as it is the only one with clever people AND decent funding.
But now having looked back at it, that "double parallel twin" which got most of the press was just a mule ("proof of concept" in PR speak) made out of (presumably) GSXR1000 parts (including cut down heads). It was to prove that the contra rotating crank idea and general layout worked, and was followed by a true VR arrangement with their own head incorporating 3 cams - unlike horex the centre one operating all inlet valves and the inlet ports going between the inlet and exhaust camshafts basically as I described above (bit chuffed about that). It would be fascinating to know how that engine actually went, so much of the Csysz thing was all smoke, mirrors and PR I would not take the 220hp claim on face value, but who knows.

(sorry Kiwi, have now seen your comments that VW made a similar system for racing but never ran it. Can't be arsed re-writing all this idle blather...)

So, back to Suzuki's new MotoGP bike. Wouldn't it be fascinating if it was a transverse version of the VR4 / Csycz Z-line concept? Sadly, I reckon it'll just be another boring I4, but we can but hope. Interesting journey here, thanks for the opportunity David, Pheonix & Sideswipe. We may well all be talking out of our arse, but that's what makes this site so good, as Ducati_750 pointed out.

I've never thought much of the Horex. Its got an extra 2 cylinders, forced induction (gone from super to turbo I think), an extra 200cc and from what I can see the planned 2012 production version is outputting around 160bhp. That's not something you want to use as a basis for a race engine.

Concerning inlet ports and airboxes, I'm fairly sure the role of the airbox is there to provide a stable induction "source", that has minimal external influence from the intake pulses or ambient conditions, allowing more consistent tuning conditions, which in turn enable the engine to be tuned far closer to theoretical limits.

Regarding port flow, I think phoenix1 meant "kink" or "change in direction", although this angle is usually very minimal in modern designs, its still a headache for designers. It translates to lost energy as the charge must decelerate in one vector and accelerate in another. Picture it bunching up at the kink, increasing pressure and losing energy to heat, before expanding and continuing down the port at a slightly lower velocity. This means the valve has to be open for longer to allow the same volume as a theoretical design with a straight tract.

Why not just bring it in at a different angle to eliminate the kink? One reason is combustion chamber volume; a less vertical port (in regard to the cylinder) would require a higher chamber roof, sacrificing compression, or adding weight and complexity to the piston crown. The other reason is turbulence. There is a peak valve angle for any rpm that allows the most mixture in while pushing the exhaust mixture out during overlap (quite similar to the 2 stroke days), while also providing the desired conditions for the air/fuel mixture 2 strokes later. From what I gather this means having a more concentrated charge surrounding the spark plug for a more controlled burn and then leaning out and fast burning as the piston travels down the stroke.

Yes, back to Suzuki, I doubt it will be a VR engine, but would not be surprised to see a "long bang" I4, although I think it would be a huge kick to their pride. I would suspect something different purely for the purpose of corporate identity.

Perhaps an I4 with the outside pistons paired on the crank at 360degree firing orders, and the inner pistons 90 degrees after, a real imitation V4 firing order! THAT would be awesome (as would being right ;) )

They are sexy! Like the little support plate connecting them too

"There is clearly a benefit to Suzuki to have spy shots of their bikes appear in the media, as it raises the profile of Suzuki's racing program, and generates a lot of publicity. "

I'm just grinning at the fact that Suzuki is perhaps using the media to get involve with "2013 silly season", hinting of a possibility of a competitive factory ride? It's a gamble if Suzuki does grid up in 2013 because they seems to start & end the season with the same bike like how Ducati used to be.

It's all my personal speculation but doesn't their one factory bike format and some "leaked info" of a cross plane approach seems to be trying to poach a certain rider? Ha...

I hope they come back ASAP, and the bike is competitive.

There's way too much talent coming up through the ranks to be pigeonholed in the 4 good seats at the other factories.

Good to hear suzuki is trying to get back in motogp in 2014 because motogp needs more manufacturer and more prototype bikes. Im really not favor the crt in my opinion cuz i believe motogp is prototype bike racing. The suzuki bike looks sexy, i hope if stoner decide to come back then i want to see him riding this bike and be competitive at the very start top 5 would be fantastic.

The shot of the bike stripped outside the garage is what made me suspect they were intentionally leaking the pics. Why would you strip the bike, and then roll it out more or less into the pit lane for anyone to see the details. It's like it was intended to pose for the photographer(s) there.

Considering the lengths the other manufacturers go to in hiding design details. Wholly naked pics of the current Ducatis are non existent as far as I know and the partial shots we see have all been inside the pit box snapped while someone was working on it. Honda goes to the length to put up privacy screens or roll the doors down whenever they're changing setups. For Suzuki to roll the naked bike out the back door to sit alluringly by it's lonesome makes ya wonder.

I hate that CRT classification as they've already moved far past that narrow definition for what these bikes are intended to be. I like the creative spin on the initials to Constructors Race Team. I think that's closer to the spirit of what they're getting at. Modified production engine or prototype, factory privateer production racer for sale or cobbled together prototype from various engineering firms all fit the larger prototype class IMO. This Suzuki so far looks a full factory prototype but who knows... maybe a prototype for an ART style turnkey racer.

When Suzuki threw in the towel at the end of the 800 era, I was disappointed. However, in return Suzuki essentially gave up a year (or two) of racing for unlimited testing time for a entirely new bike.

They are testing extensively...on a Japanese track with Japanese test riders.
Which they can certainly do all season long while competing in MotoGP.
And since they don't have A-level GP riders contracted, that's all they can do anyway.

Spies will "forgive" Suzuki and join their MotoGP effort with Schwantz as team manager. Just in time for the Texas GP next year...I'm just sayin'......

that he won't have a choice? If you're not, I am! Open the books, Spies is history at Yamaha.

short answer yes...silly season started this year with Rossi "interviewing" his dad followed by the Stoner announcement...big fan but truth is Spies is making it tough to justify a factory ride contract with Yamaha..since, for most riders, you are only as good as your last race. The Suzuki project is testing the water with "spy" shots. Schwantz could be a great team manager..Pepsi as a sponsor with Ben Spies and Randy DuPuniet at Suzuki MotoGP next season...

.blah blah blah..what do I know....

re: "There is clearly a benefit to Suzuki to have spy shots of their bikes appear in the media, as it raises the profile of Suzuki's racing program, and generates a lot of publicity."

BFD. meanwhile batta's put out to pasture and the yosh powered team crescent languishes while hammamatsu wastes time (and money) building a "prototype". a "prototype for a race series who's owner has openly stated his intention to DO AWAY with prototypes and whose defending champ has just announced his retirement. nothing wrong with this picture, i'm sure it'll go over just as good as their last 10 years in grandprix.

(ring, ring) hello...? suzuki, the phone is for you. it's lucrative car industry calling.

Suzuki can read Dorna's announcements on future rule changes just as easily as anyone else. There is a possibility that this is their next generation superbike in development and CRT entry wrapped into one. An 81mm bore clean sheet cross-plane crank engine design could be potent compared to current CRT engines. There's a logic to saving money and backing off from racing your existing dated design and killing 2 birds with one stone with a brand new design as Aprilia seem to have done. Continue to use the prototype/development engine and chassis tooling to make low quantity racers then make a slightly watered down permanent mold version to produce in volume for the street and WSBK. That approach would mesh quite nicely with the proposed future rule changes and make very efficient use of Suzuki's limited R&D funds.

I'm not saying that is what they have done but your equally deep read into a few pictures could use a dose of optimism.


Agree completely. As I understand it, this was the whole purpose of switching to 4 strokes in the first place. Its what the word prototypes means...

If the manufacturers operated like this since day one it would have SAVED them money, all of them, they would have only had to support one product line, instead of two. Except it turned into a p!ssing contest with everyone forgetting the goal of actually producing bikes, and we ended up with a divergent evolution of motorcycle that bears little/no resemblance to the ones that actually make them money.

The 4 stroke era was the manufacturers chance to make their road bikes better, by making them more like their prototypes. To reign in costs, we now have to make the prototypes more like our roadbikes.

2 steps forward, one step back, as they say...

I'm thinking that this M1 style firing order described by Kevin Cameron may in fact be the same firing order as the Honda RC45 RVF750. That is:

1 | 2 | 3 | 4 (cylinder)
I | C | E | P (0)
I | P | I | P (90)
C | P | I | E (180)
C | E | C | E (270)
P | E | C | I (360)
P | I | P | I (450)
E | I | P | C (540)
E | C | E | C (630)

(as much as I want them to, those letters never line up to spell "EPIC")

Theoretically, this has all the advantages of the M1, the constant angular momentum of the crankshaft, without the end to end vibrations. Slightly higher rotating mass to balance but Suzuki may just reduce flywheel size to accommodate this.

I guess evidence for this is the twin exhaust pipes in the pictures, which would pair the outer cylinders that fire exactly 360 degrees apart, and the same for the inners. The views in the pictures can't confirm this, but I think from my understanding of the engineering, I'm pretty happy with my hypotheses - until someone debunks it :(

Bonus: It would probably sound something like this:

I don't get your table above, it seems to show one power stroke per rev? Sadly, since the demise of the 2-strokes it's a 720 degree cycle.

Looking at ignition events, an RC45 360 degree crank 90 degree v-4 ("even fire") would have 0-90-360-450 or something like that. Basically two 360 vertical twins running 90 degrees apart, or two 90 degree v-twins running 360 degrees apart.
The only other option with a common-crankpin 360/90/v-4 would be 0-0-90-90 ( which I believe is what the original "twin-pulse" desmosedici was (soon rejected).

You can't replicate that firing order with a 90 deg crank I4, because only one cylinder reaches TDC at a time, so you can not have the 0-360 or the 90-450.
You could either have 0-90-180-270 with a long gap to zero again (transmission killer), or something like 0-180-450-630 - effectivey two overlapping 180 deg parallel twins 90 degrees apart. I assume the R1 (and M1?) are the latter.

If I've got it right in my head you could the Yammie firing order with a 180 degree crank V4 - 0-180-450-630. Yes, of course - because physically they are two 180 parallel twins 90 apart.

Didn't Honda change from a 180 to a 360 crank at some stage? I think only the early proddy V4's (VF750 etc) were the 180 crank, the RC30 and 45 were both 360.

Perhaps I didn't spend enough time describing the crank, I might have got a bit carried away. I say it's a "v" plane instead of a cross-plane but maybe it should be an L plane?, because the crank pins for cylinders 1 and 4 are at the same position (firing 360 apart), and the same deal with the pins for cylinders 2 and 3, although phased 90 deg after cylinders 1 and 4. From the end the pins would form an "L".

This is not the Yamaha crank. Its the Yamaha crank with pins 3 an 4 rotated another 180 degrees.

You are correct about the Honda, they did change from a 180 degree offest to a 360 degree offset for the RC30/45 and the back to 180 for the VFR800. The firing order for the RC's is 0-90-360-450, and that's exactly that the L-plane crank would allow.

Sorry about the diagram, it made sense in my head. across the top I had listed each of the cylinders, and then going down their stroke by crank angle (Intake, Compression, Power, Exhaust). The numbers in brackets is crank rotation.

Another way to think of it would be to start with hypothetical RC45 motor, with the front cylinders (name them 1 and 4) on the outside of the 2 crankpins. Then imagine pushing the rear cylinders around 90 degrees until they are inline, with 1 and 4 moving outward to let the rear cylinders fit. Then imagine splitting the crankpins and also moving the inner pins forward 90 degrees to maintain the firing order. You get an L shape crank.

I hope that clears it up.

I see where you're coming from now.

The v-plane as you describe it there is just a conventional 180 I4 with #2&3 rotated 90deg, and yes, same as a 360/90/V4.
Or, to put it another way, 2 x TRX850's side by side, 360 degrees apart.
And the 270 degree crank parallel twin as used in the TRX850 was originally proposed by Phil Irving in the 1950's (ok, he proposed 72 deg, but same same).

There's nothing much that hasn't been thought of before.


I just think its an interesting concept with some fairly solid advantages and most importantly it would be unique at a production level. The twin exhausts are my only real evidence but I just think it would be neat if this is what Suzuki were up to.

Hello, I've been lurking on the site for a while but hadn't signed up until now.

This might sound a little OT initially but bear with me.

Thanks for another interesting article David. I think the article and the comments about power not being everything are spot on. I think Jerez on the exit of the final corner with Casey vs Jorge and Dani vs Cal showed this quite well, the Hondas literally screamed up the straight initially by just getting the power down incredible early.

Jorge who is typically super strong on the brakes only gained what he'd lost on the initial acceleration through braking, Cal seemed to be doing the same.

So getting onto topic

I suppose the Ducati problem is that while it's quick at the end of that straight, it's actually slow in the first 100/200 metres out of the corner, and these corners come up 10 times a lap vs the home straight once a lap.

While they seemed to have 'solved' at least the feel of the front end, it may still be trying to tuck early, but at worst, the riders seem to know when it's going to go.

The back of the bike is causing problems. Going back to that super smooth acceleration that the Honda has out of the corner.

So the Ducati issues seem to be aggressive power, bad electronics, both of which cause oversteer and a lack of drive.

If you think, to accelerate at the maximum, you need to be literally at the point where the tyre is going to start sliding, the absolute limit of grip, the absolute quickest is probably allowing a tiny bit of slip, and you also can not let the bike wheelie too much as that's also wasting drive, but a little bit means the entire weight is on that contact patch, so you should get 100% out of the tyre.

With the above in mind, I think the oversteer is partially caused by the electronics, my theory is that the 'cut' on the Honda and Yamaha electronics is very smooth, the Ducati is not. Think of the corner exit like this;

1) Rider hits apex and rolls on throttle for exit
2) Rear end of bike starts to load weight, front becomes light and bike is starting to stand up
3) Engine power delivery becomes non linear and overwhelms rear grip
4) TC cuts in
5) Weight transfer is momentarily affected, bike starts to go offline
6) Power comes back, weight is going back where it should be.
7) TC cuts in, rider now starting to struggle with exit because constant weight shift has messed up geometry and corner exit angle.

This is what I imagine happens when you see the very fast cut/go/cut/go exits happen on track.

The ideal I suppose is to do step 1 and 2 and miss all the TC bits, but with the power involved and the speed this happens, I assume the electronics have to do some work. I suppose the trick is letting the electronics kick in, but not enough to upset the balance of the bike - the weight on the rear, the rear suspension not being loaded/unloaded.

It's a big piece of work they've got to fix. And with changes to the swingarm, electronics and engine, It looks like they're having a serious go at it.

It's also nice to see JB and the Team actually being invited to test. Paying a team of that calibre and not bringing them to tests was not something I'd have expected a guy of Prezioso calibre to do.

Anyway, it looks like they're moving forward, I think in time the bike will be up there.

I know Honda and Yamaha are going to move forward, both want the title, but I think the major areas for innovation at Honda and Yamaha are done with for this year, neither will do anything too risky, so I think small gains will be made. Ducati still have to step upto the mark, so big gains are available.

Once they sort this section out, they'll have a front that delivers feel and a back that allows the bike to accelerate out of corners. Now they seem to have that, at least in test form, judging by the press release, I'd expect they'll now start beavering away on refining the smaller details of each area, which is what Honda and Yamaha have been doing for the last 9 months.

If Ducati get on top of the podium in the dry this year, It'll be a testament to how hard a few guys have worked for the past few years. I think it's not impossible, but I also think it's very hard, especially with Casey and Jorge consistently putting lap after lap together.

It'll be interesting to see how the rest of the year pans out in GP.