A 4 Pound Engine That Produces 3 Horsepower – IOTW Report

A 4 Pound Engine That Produces 3 Horsepower

It may not seem like a lot, but the potential uses of a super light weight rotary motor that you could carry in your hand will be enormous.  For proof of concept, the manufactures replaced a 40 pound go-cart engine with the 4 pound x-mini.

The makers, LiquidPiston of Connecticut, aim to get their engine down to 3 pounds and up to 5 horsepower. The only limiting factor will be the weight of the fuel needed to run the thing.

More

Yankee ingenuity at its finest.

19 Comments on A 4 Pound Engine That Produces 3 Horsepower

  1. I’d want to see it scaled up to see how it compares to the original Wankel rotary engine in the Mazda auto. If I remember correctly, the engine was a great performer, but when it got up to top end RPMs, it sucked gas like a thirsty camel sucks water.

  2. @B Woodman; I remember the introduction of the Mazda RX-7 with the Wankel as competition to the Datsun 260Z (or maybe the 240) in the light weight, low cost sports car market. The manager at the McD’s I worked part-time at got one and it just flew when driven right. Don’t know about the mileage though. Nice design as well.

  3. a DA-100 at 5.5 pounds output almost 10 HP, sips fuel 2.5oz per minute at 6000 RPM. Or a DA-50, under 3 pounds at 5 HP. Maybe not as versatile, but the size/weight to power ratio has been around for a while if we’re just talking engines. You can find them in your weed whipper or on scale aircraft.

  4. With the Wankel, I thought there was some kind of problem with seals.
    Not a car guy, and getting senile.

    Anyway there was a guy at MIT back in the 80s who designed a fission engine. Water vapor as moderator, and the pistons equipped with fissile material, that became critical towards the end of the stroke. Vapor would expand, pushing the piston, and as it expanded it loses it’s moderating capacity, ceasing the fission.
    Pretty cool. But since Americans are terrified of the unknown, and have no desire for (virtually) limitless cheap power, nothing became of it.

    izlamo delenda est …

  5. @BWoodman: I had a Wankel-driven 1973 Mazda RX-3 when I was young. Darn thing redlined at 7000 RPM and could hit 125 MPH with no problem. She did eat gas, and keeping it running smoothly was a constant proposition. Lots of backfire.

    LiquidPiston’s tiny rotary, and it looks like it will pan out, has unlimited applications. Amazing little efficient machine!

  6. @Tim – you remember correctly about the Wankel seal problem. In that design, the seals were at the three apex points on the rotor and keeping them properly lubricated was the issue. The engine in this article has the seals at fixed points in the housing, and can therefore be lubed via fixed ports in the oil system. This is (in my totally amateur opinion) a major improvement.

    I spent a few minutes looking at the videos and then went to the company’s web site. The do provide some interesting information, but not key details as this is proprietary and still under development. One nice tidbit, the small gas engine uses spark plug ignition of course, but they are also building a pair of compression ignition diesel engines with 40 and 70 HP targets.

    The RPM range is 1,000-14,000 for the little gas guy, and 500-5,600 for the bigger diesels.

    One disappointment (temporary I hope) is the absence of torque info.

  7. I had a 1982 Mazda RX-7.
    I loved that car, drove the hell out of it.
    Fast and nimble.
    Solid as a rock too.
    It had a 20 gallon gas tank!
    Unheard of for a small car like that.
    It did eat fuel at high speed.

    I believe the RX-2 in was the first production Wankel in Japan.
    It was a 2 rotor.
    They were working on pairing up the third rotor but had issues with the design.
    Small engine, I replaced the clutch myself in that car.

    Years later I had a 1993 RX-7.
    Sigh…miss those days!

  8. Perspective,
    Military and gubberment funding. DARPA, the same people that gave us what eventually became the internet. It was originally developed for communications redundancy in case an enemy attack cut off any one area. So not necessarily a bad thing.

Comments are closed.