Tiny Gasoline Engine Fitted With A Custom Billet Waterpump

We don’t typically use gasoline engines smaller than 50 cc or so on a regular basis. Below that size, electric motors are typically less messy and more capable of doing the job. That doesn’t mean they aren’t cute, however. [JohnnyQ90] is a fan of tiny internal combustion engines, and decided to whip up a little water pump for one of his so it could do something useful besides make noise.

The pump is built out of billet aluminium, showing off [JohnnyQ90]’s machining skills. The two pieces that make up the main body and cover plate of the pump are impressive enough, but the real party piece is the tiny delicate impeller which actually does the majority of the work. The delicate curves of the pump blades are carefully carved out and look exquisite when finished.

The pump’s performance is adequate, and the noise of the tiny gasoline engine makes quite a racket, but it’s a great display of machining skill. If so desired, the pump could also do a great job for a small liquid delivery system if hooked up to a quiet electric motor, too. The aluminium design has the benefit of being relatively leak free when assembled properly, something a lot of 3D printed designs struggle to accomplish.

We’ve seen [JohnnyQ90]’s micro engine experiments before, too — like this small generator build. Video after the break.

31 thoughts on “Tiny Gasoline Engine Fitted With A Custom Billet Waterpump

      1. Yes, true billets are the raw material between casting and forging into the final product like bar and sheet stock or forgings. Stuff that says it is made from billet is just made from bar stock.

  1. I wonder if such engine would be enough to power laptop and small led light in bicycle trip freelance/homeoffice situation. Given that you go ditch the mains AC inverter and go direcrly to DC. Also how long it can run without maintenance given it has enough liquids. Small engines tend to seize more easily than big ones.

    1. I have to ask why would one attempt this? Since a computer such as a Raspberri PI or any one of the other SBC’s available now can be run from a pretty low power source, wouldn’t a small solar panel make more sense charging a batter pack? Then there’s the noise factor.

  2. You could also just run the output of the pump through the cooling jacket and then on to it’s destination. This could either be a recirculating system or a total-loss system such as moving liquid from one location to another.

    1. Then it would need a neat little thermostat, which needs a bypass port. Some larger engines use a dual valve arrangement where as the engine temp goes up, coolant is rerouted. By the time all of this gets constructed, for such a tiny engine, there is a fair amount of added material and space taken up.

  3. How much shaft power is getting to the water pump, and why does the “gasoline” engine require 20 watt-hours of lithium energy storage hidden beneath it? I’m sure the answer given will be “to run the spark plug”.

    It’s reminiscent of those “water powered” quack cars that used battery power to fire oversized spark plugs to make steam in the cylinders from the water they “ran” on. (They ran just fine on the water, until the battery went dead, that is.)

    1. It needs the batteries to run the spark plug. Because gasoline engines need a spark to ignite the gasoline. The two 18650s just happened to provide the required voltage and have a very convenient packaging.

      I mean…I get it, be critical of what you see and what you believe, sure. But your comment is on borderline conspiracy theory level. Maybe tone it down a bit, not everything is “fake news”.

      1. Not everything is fake news… But browns gas cars that run on water definately qualifies as such.

        There is a race to clean energy cars that don’t have to refill for an hour at a charging station… Car manufacturers chasing gas, diesal, hybrids, plug in hybrids full electric, hydrogen…

        Yet not a single one chosing to invest in “browns gas” all these extremely smart engineers and chemists and they all took that idea and chucked it in the rubbish bin when it’s a DIY 15 min alteration… Why do you suppose that is?

        And if you say “because petroleum companies are blocking it” I want an explanation of why every other alternative fuel is being explored but not this one… I want a logical rational thought out argument…

        1. “Browns gas” is just a stoichiometric mix of hydrogen and oxygen. Hydrogen is bad enough for fuel, it has terrible energy density, but to have a tank of pre-mix H2/O2 is just an explosion waiting to happen.

          Whats a 15min alteration? You dont mean those snake oil products where they put an electrolyzer in the car, do you?

        2. I was talking about the engine in the post and the original commenter implying that it might be fake, since it needs a fairly big battery to run.

          And the fact that you’re suddenly talking about some strangely named tech that’s apparently supposed to be better than everything we have is just a huge red flag for me to file it under “it’s probably a pile of horseshit”

      2. Phrewful says Maybe tone it down a bit, not everything is “fake news”.
        Whoa. Touched a nerve? Who hurt you?

        I’ve had lawnmowers, moped and motorcycle that did not require batteries of any sort to generate a spark. Heck, a Cessna 172 doesn’t even need a battery to run the engine and fly.

        In the video the batteries stored in the base contain about the same amount of energy as the fuel put in the fuel tank, and the actual power to run that water pump just isn’t very much.

        So it’s a simple question: Given the amount of energy stored in the batteries, what’s the actual output power of the device, compared to what the battery delivers?

        And: If the device really requires batteries of such energy capacity, how much average power do they put into the spark, compared to the energy from burning the fuel?

        1. Magnetos. A self contained generator, points and distributor. Battery is used to get the engine starter engaged and sequence the fuel system.
          Same as a lawn mower or any other small gasoline engine.

        2. But those lawnmowers, mopeds, and motorcycles have magnetos to fire the spark plug. It’s clear that a magneto would be an unnecessary complication to this design, so a couple of cells are substituted. The CDI ignition box is clearly visible next to the cells.

          This is just a small model engine made by a hobbyist. Why are you bringing “quack cars” into the discussion?

        3. “Who hurt you?”
          Idiots who keep calling “Fake news” on anything they don’t understand. Though I wish their stupidity would hurt them.

          You still miss the point. The engine does not require the amount of power those two batteries deliver. They were just handy.

          Also, have you seen the flywheels on lawnmowers, mopeds and motorcycles? And what’s sitting next to them? That huge thing called a magneto? Or have you seen what’s mounted to the engine of a Cessna 172? Yes, you’re saying “This big engine with a GENERATOR attached to it can operate without batteries, why can’t this fist sized one without any accessories?”

          But, if you’re not just here to cry “Fake news” and really want to find out:
          https://www.stirlingkit.com/collections/new-arrivals/products/cison-l100-diesel-engine-evaporative-cooling-4-stroke-single-cylinder-gasoline-engine-model?ref=8_o3dxgl2qw

      1. Nitro is an interesting fuel as it produces its own supply of O2 basically. The ratio instead of 14:1 is around 1.5:1 so the cylinders can be filled nearly full of liquid, Nitro does not vaporize and it will not ignite with a spark. The ignition systems require either a glow plug as in the model engines or as in drag racing, the plugs are heated by the magneto to the point the tips are red hot instantly by the system and that must be at an exact time before top dead center or the engine literally blows up. You mention energy density and I have to question that to a certain point. A gallon of gas has around the equivalent of 14 to 17 or maybe it’s 21( I don’t recall exactly) sticks of dynomite which is Nitro glycerin soaked into hemp based materials so the space a stick takes up is not all fuel. Gasoline obviously has to be vaporized before it will combust and then when the vapor is compressed, it must be left as a vapor. Compress it enough fast enough it ignites spontaneously, or slow enough it should return to a liquid if it is cooled. Obviously gasoline is not the first choice to make power at the levels a Nitro racing engine makes simply because you cannot get enough fuel and air into the cylinders and keep ignition under control. Nitro cannot be mixed with gas but in the past racers did use Nitro and high test gasoline in combination and it usually ended badly for the engines at some point. But then it ends up badly for every straight Nitro burning engine too, it just happens faster. I used to race and never have I seen a gasoline engine burning fuel out the exhaust like a Nitro engine and never has a gasoline engine produced the power a nitro engine can at the same displacement. The point is a gas can be compressed where as a liquid cannot. So the limit comes at the point where there is simply no room left in the cylinder to fill with liquid Nitro. They hydraulic and explode. I’ve never had the pleasure to play with Dynomite or Nitro Methane myself so I cannot make a comparison between which will blow a bigger hole in the ground or destroy anything of value, but I do know gasoline is not the first choice for those that are tasked with bringing down buildings or building roads in mountains. I have watched videos of mines blasting rock or coal and watching debri flying into the air hundreds of feet is pretty impressive, they may be using more modern explosives such as C4, I can’t say, but when saw dust soaked with Nitro was the choice of miners it was still awesome. Nitro or gasoline? Kind of hard to get a comparison from something that can be stuffed into small hole bored into a rock and makes its own oxidant with something that must be vaporized and supplied with O2 at the proper ratio in order to combust

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