The Kneeslider

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Moto Guzzi W103 – 3 Cylinder V-Triple Motorcycle Engine

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Moto Guzzi W103 3 cylinder engine
Moto Guzzi W103 3 cylinder engine

Have you ever noticed how once you start looking for things, they just seem to jump out all over the place, like W configuration engines. After mentioning the Anzani W3 the other day, I came across another one I had never seen before, this one is the Moto Guzzi arrow W103, a 3 cylinder engine in a V-Triple, arrow or “W” configuration.

This arrow configuration engine was designed in 1981-1982 by Lino Tonti. It displaces 992cc, with 3 cylinders set at 65 degrees. Valves were push rod operated from 2 cams in the block by the central cylinder. It was equipped with three 30mm Del’Ortos. The factory identifier was W103.

What you see in the photo was as far as development went, which is really too bad, it would have been interesting to see this mounted in a running prototype motorcycle of some sort.

I came across this beauty in a really stunning book, if you’re a Moto Guzzi enthusiast, “Moto Guzzi – The Complete History from 1921.” Absolutely everything you ever wanted to know about Guzzis from day one, every model, technical details, great photos, if you have a Guzzi or you are interested in the marque, this book is a must.

Note: The book uses the “arrow” designation for the cylinder layout instead of “W” which I wasn’t used to seeing, but it makes sense and is actually more accurate, though the factory used a W prefix for the identifier. Is there a consensus on which is more correct? Since there are so few engines of this particular type, both are probably acceptable. Interesting.

Comments

  1. I have long been a Guzzi fan having owned one in the early eighties, a ’71 ambassador. This motor is a stunning work of art. It is as you as you say a pity that Tonti never put in a it on wheels.

  2. sweet! Like a slice out of a radial engine. I wonder what it sounds like. I love the roar of my Yamaha inline triple, but I wonder what this config would idle like and sound like at WOT.

  5. I’d be more likely to use the “arrow” naming designation for engines of this type because VW uses the “W” designation for the layout in their W8, W12, and W16 engines which actually have 4 banks (2 Vs joined together) and look more like a “W” than these.

  6. The ‘arrow’ makes more sense since it’s a single crank. And as kwj points out the VW engines that carry the “W” designation are actually two narrow angle “V”‘s joined at the crank. In the case of VW, it’s interesting to note that in German, the letter “W” is called double V. So, technically, the Germans are calling the engine a ‘Double-V’ but that distinction gets lost in translation.

    All that said, there were some three bank aircraft engines that also carried the “W” moniker.

  7. I like it! I was asking myself where the fuel tank would go, but many makers have stuck the fuel under the seat or in the frame (Buell) so that question has been answered.

  8. I sort of like my own neologism, “V-Triple” to describe it, but that’s just my own off angle perspective.

    Looking at the engine a bit more, you have to wonder where you would route the center exhaust, sort of makes that clean and simple dual exhaust routing Moto Guzzis have a bit more difficult.

  9. Split the exhaust from the center into the the two pipes from the “outboard” cyclinders. At least it would be symmetric.

  10. SteveD, what are you thinking? Splitting the centre exhaust pipe will produce the same stylistic disaster that befell the Suzuki triples and the Triumph Trident. The Triumph Hurricane and the Kawasaki triples, on the other hand looked great, in part because of the asymmetry.

    BTW, call the Guzzi layout a ‘W’, as most people immedeately will know what that means. (Test this by asking your friends if they’ve seen the new M-G ‘arrow’ type engine. Methinks you’ll get some puzzled looks.)

  11. I agree with kim, definitely embrace the asymmetry here and dump two pipes out one side together and the other by itself like the Kawasaki and Yamaha triples. Triple owners (like myself) have a weird desire for others to know they have a triple and not a boring 4-cylinder.

  14. Hah, Freeman beat me to it, I was going to suggest trident as well.

    VW really has W engines, so this isn’t one, maybe a Tri-V engine or something else. I think radial triple is how I would describe it, or a radial 3-cyl.

  17. Wouldn’t reverse facing cylinders be the simplest choice for exhaust packaging. With a little bit of Nasa developed BMW style heat insulation to keep things cool. Never understood why so few bikes have used this.
    I wouldn’t call the VW (hence Bugatti) engines W configuration. They’re really just two VR engines joined at the bottom end. I’ve heard them described as VV or double-V engines. Besides the original W configuration was a 3 bank. Like the Guzzi engine above.
    Hmmmm…what about a 6 cylinder version.

  18. What about fan-tripple. I’ve heard the Anzani called that. It made sense to me. Sounds like the W moniker is in a trademark dispute anyhow.

    Foreward facing exhaust porting keeps the hottest parts in the cool breeze.

  19. Haha we’re sensitive SteveD 😉

    But seriously three-into-one is awesome too. Don’t even get me started on three-into-three off to one side *swoon*

  21. I know that there would be heat issues but with a motorcycle like the Guzzi where two cylinders are sticking out the side of the bike. It just doesn’t make sense to me to have the exhaust pipes curling down underneath the cylinders. Even Stellans Harrier with the pipes going over the cylinders seems like a better idea. The benifits as I can see them are shorter pipes=less weight, less twists and turns of the pipes=free-er flowing exhaust, and since the pipes aren’t being routed under the engine less of the heat is being radiated and convected to the engine itself. Hopefully reducing the load on the radiators. Maybe resulting in smaller radiators or less fins on air cooled models= less weight again.

  22. Interesting – it looks like it was based on the 750 motor. Note that the head on the central cylinder is different. I think the sump may be deeper too.

    Kenny – some bikes have had the pipes flowing over the top of the cylinder but it isn’t common. I guess I wouldn’t want to have a hot pipe running that close to my knees. I rode a Guzzi for some years and having a hot cylinder next to my knee was all the heating I needed!

  25. As an entusiastic Guzzi Rider, I would love to see the Arrow engine in production. Better that than the new sci-fi design.

  26. As intersting as it looks, I’d say they had their reasons why they never built it. Why add a third push-rod, 2 valve, air-cooled cylinder which forces the engineers to come up with major changes? Kind of reminds me of the Triumph triples, too little too late. Why not update the engine to DOHC, with 4 valves, watercool it and give it higher compression. Or like ONMAG suggested, supercharge it.
    There is no letter in our alphabet for this kind of triple or for Bugatti’s engine configuration. W comes close and people know what it stands for but it suggests four banks and two cranks, like two Vs would have. And that would be one crank too much.
    And anon, you wrote: “in German, the letter “W” is called double V”, that’s not the case. In german, the letter “W” is pronounced like the english “V”, and the “V” is pronounced like an “F”, but who cares.