“World’s Smallest” Working V-12 Motor

CNC & Machining Energy & Sustainability Workshop
“World’s Smallest” Working V-12 Motor
YouTube player

A Spanish craftsman named Patelo skillfully designed and fabricated this tiny working V-12 motor from stock stainless steel, aluminum, and bronze for his grandchildren Sara, Carmen, Jose and Pablo. It took more than 1200 hours of work. Not counting the 222 screws, he machined all 261 pieces himself. The engine operates via compressed-air injection, has 12cm3 total displacement, 11.3mm cylinder heads, and a 10mm stroke on each piston.

His video log of the project is fairly long, at almost ten minutes, but includes some really amazing footage. It’s divided into four main parts:

  1. 0:10 – Machining the connecting rods (photomontage)
  2. 0:50 – Machining the crankshaft
  3. 2:28 – Assembly
  4. 8:05 – Operational testing

If you just want to see it go, click here for Part 4. Part 2 shows the turning, grinding, and polishing of the tiny crankshaft in some detail, and is my personal favorite. [via nerdstink]

44 thoughts on ““World’s Smallest” Working V-12 Motor

  1. Ben Foote says:

    Oh my god!

    That is sooo beautiful. Mind boggling attention to detail! Words cannot describe the amount of passion that had to go into that project.


  2. Steffen Ivan Nielsen says:

    truly amazing work! Inspires me to get cracking at some machining work myself, though I think i’d start out with a less complicated project..
    However.. I’m wondering how this genious engine runs without any sparkplugs ? Even with a diesel engine, wouldn’t it require something similiar?

    1. Frank Sanchez says:

      It’s not running on it’s own power, air is being pumped into the intake which is making everything go. I don’t actually think it would hold compression without gaskets on any of the junctions.

    2. Frank Sanchez says:

      Check out this youtube video of a V12 actually running on it’s own power: http://www.youtube.com/watch?v=mutb7KgA9NM

    3. Kyle Wurster says:

      It isn’t powered by burning hydrocarbons, says so in the description – “The engine operates via compressed-air injection”. Even so, an amazing feat of craftsmanship to behold.

  3. Anonymous says:

     I wish they would have chosen a more appropriate title for this. I was expecting an internal combustion engine.

    Beautiful work none-the-less.

  4. Anonymous says:

    Coolest Grandfather Ever!!!

  5. John Doucet says:


  6. Anonymous says:

    Who among us can tell if its a two or four stroke? And how do you tell?  (I know the answer, btw)

    1. Jeff Del Papa says:

      Its single acting.  Air and steam engines don’t use the term “stroke”, as (if double acting) you have both power and exhaust strokes, at the same time in the same cylinder, on the same piston.

      See http://the-nerds.org/Steam-101.html for pictures.

      1. Anonymous says:

        Hi Jeff,
        Thanks for you comment, I’m actually a bit confused now.  When I initially looked at the model, the two stroke give away is in the cam drive gears (same speed as the crank). 

        The thing that did confuse me a bit, and I never really got to see from the video is what the gear at the free end is. I am assuming this is a model of an actual engine – do you know what?  I work in the marine industry and have seen a lot engines and from school got a reasonable amount of exposure to steam engines but (if that is what it indeed is) I have never seen a single expansion engine arranged like that – so this might be a learning day.

        1. Jeff Del Papa says:

          I doubt this is a model of an existing engine.  Its design is reminiscent of early aircraft engines, with the external valvegear, and separate cylinders and crankcase (like the old American 400hp “Liberty” engine).  I think the builder wanted to build a small non-static V12, for indoor display purposes, but didn’t want the extra complexity  of  fuel and ignition systems that running it from liquid fuel would require. (with  the resulting temperamental running, that tiny carbs would bring, and also the “aroma” from the exhaust)

          So he built it to run from low pressure compressed air.  Had he intended to develop actual power, he would have needed a different sort of valvegear, as poppet valves do a poor job of resisting pressure from the “back”.  (its why the obvious conversion of an IC engine to steam doesn’t work – enough pressure to get actual power, and the valves lift off their seats) If it had been intended for steam operation, the cylinders would have been lagged (insulated), and fitted with some sort of condensate drain (or risk hydrostatic lock).

          Running off compressed air is something that model steam engine builders do all the time for indoor displays.  You don’t have the burn risk, should a spectator touch the wrong thing, and likewise the combustion byproducts of making steam.  Go to one of the shows I mentioned elsewhere,  (NAMES, Cabin Fever, etc) and you will see that the show’s promoter has arranged to equip each display table with a pipe manifold connected to a big air compressor (that they usually stick outside the building to keep the noise down).  The manifolds have regularly spaced valves, with barbed tubing fittings.  Exhibitors just bring a bit of rubber or plastic tube to connect the supply to their engine, and off they go.

          As to the gear on the other end if the engine, well it  sure looked like a flywheel to me.  No, its aircraft predecessor wouldn’t have had a flywheel, but for display purposes, he decided he needed something to keep it running smoothly at the low speeds typical of engine demonstrations.  (its clearly intended for low speeds, since he doesn’t appear to have made many provisions for lubrication)   You want to keep the speeds down, so people can watch the valves move, and to minimize wear on your laboriously constructed parts.


  7. Halfvast Conspirator says:

    The most amazing aspect is that his wife lets him build it at the kitchen table!

  8. Gijsbert Peijs says:

    Fantastic piece of work.

      @nhemann:disqus : a V12 – 2 stroke…. that would be a world’s first. Obviously a four stroke engine. Two strokes don’t have a crankshaft or valves for that matter.

    1. Anonymous says:


      Check this out – http://en.wikipedia.org/wiki/EMD_710  (two-strokes in up to a V-20) and also here http://science.howstuffworks.com/transport/engines-equipment/diesel-locomotive7.htm  (it shows the valve arrangement of the inlet, exhaust – and the fuel but that’s a different story)

      I agree with you that the some designs of two-stroke didn’t need valve camshafts when run with a full ported design, but there are also exhaust valve only, and like the EMD’s intake/exhaust valve versions.

      Though I think I might have been crossed up a bit myself – the cam gears are the same size as the crankshaft gear meaning they all turn at the same speed.  A four stroke’s cam turns once for every two revs of the crank shaft.  What is confusing me is the gear at the free end of the engine.

  9. Anonymous says:

     I wish they would have chosen a more appropriate title for this. I was expecting an internal combustion engine.

    Beautiful work none-the-less.

  10. Charles Johnson says:

    It is more than likely a two-stroke, but not in the same way as a “standard” two-stroke internal-combustion engine.
    The power stroke and intake stroke are combined, and there is no need for a compression stroke.
    In a more common two-stroke engine, like a chain saw or moped, the valves open and close due to air pressure, although more complicated they could be controlled by a cam shaft, pushrods and rockers; as is the case here.
    In this case, the intake valve opens just after the piston reaches the top. Compressed air enters the cylinder, pushing  the piston down. The intake valve closes as the piston reaches the bottom. Just as the piston passes the bottom of the stroke, the exhaust valve opens until the piston reaches the top. Then the process starts over again – two strokes: power and exhaust.

  11. Charles Johnson says:

    And, the music is freakin’ awsome

  12. Jeff Del Papa says:

    This is a fine example of craftsmanship, and the video is very well made.  Its even a scratch design. However the claim of “worlds smallest” is a bit optimistic.  There are far smaller v-12’s out there, some of them even functional internal combustion engines.  (this one is an air motor).  Visit one of the large model engineering shows (NAMES, Cabin Fever, and PRIME in the US, or the UK national show) and you will see a lot more like it.

    Signs that this isn’t truly small  – he is assembling it with the assistance of a stand mounted magnifier, and not a 20x stereo microscope.  And some of the fasteners, and all of the major components can be picked up without the aid of tweezers.

    Personally I can’t do small, I am too ham-fingered.  If it were up to me, I would use no fastener smaller than a M10.  If you put me in the same room with a #00 tap, it will break.  I don’t have to know its there, I merely have to get within 2 meters of it, and it will spontaneously snap.  While I do regularly work to the precision that that model exhibits, (0.01mm) I am far happier when the workpiece needs two people to lift it onto the milling machine table.


  13. Bruce R Perry says:

    I want one!

  14. Dan Braithwaite says:

    amazing work! but here is a fuel driven v12 in a fully working model replica ferrari 312 pb


  15. leo says:

    the only words that i said to myself on the whole video WOOOW. excelente amigo. your true craftsman.

  16. don says:

    It’s increadable what man can do , with imagination and time…job well done

Comments are closed.

Discuss this article with the rest of the community on our Discord server!

I am descended from 5,000 generations of tool-using primates. Also, I went to college and stuff. I am a long-time contributor to MAKE magazine and makezine.com. My work has also appeared in ReadyMade, c't – Magazin für Computertechnik, and The Wall Street Journal.

View more articles by Sean Michael Ragan


Maker Faire Bay Area 2023 - Mare Island, CA

Escape to an island of imagination + innovation as Maker Faire Bay Area returns for its 15th iteration!

Buy Tickets today! SAVE 15% and lock-in your preferred date(s).