The LiquidPiston offering is now closed and is no longer accepting investments.


The combustion engine reimagined


The combustion engine reimagined

Bloomfield, CT
Business to Business
LiquidPiston, Inc. (LPI) develops advanced rotary internal combustion engines based on the company’s patented thermodynamic cycle and novel rotary engine architecture. Our engines are compact, powerful, quiet, efficient, low-vibration, multi-fuel capable and scalable from 1HP to over 1000 HP.


Price per Share
Min. Investment
Offering Type
Offering Max
Days Left


Price per Share
Min. Investment
Offering Type
Offering Max
Days Left
This offering ended on April 04, 2020 and is no longer accepting investments.

Reasons to Invest

Up to 10x smaller and lighter and 30% more efficient than a diesel engine, with 51 patents issued and pending
$9M in Department of Defense contracts with DARPA and the U.S Army. $1.1M in partner pilot studies signed in 2019.
Raised $2.1M from two fully oversubscribed public offerings from over 1,180 investors

By rethinking the engine starting with first principles, engines can be significantly improved on virtually all parameters - efficiency, weight, size, vibration, and noise  ||  LiquidPiston is making this a reality, with potential to disrupt a 150 year old industry

Thinking "outside the cylinder"

Starting with the physics of how engines operate, LiquidPiston Inc. (LPI) has redesigned the traditional internal combustion engine and developed an innovative, efficient alternative. Building on over 15 years of R&D, LPI provides a power solution that can scale to address the $400B internal combustion engine market and can be a key enabler for emerging mobility technologies including electric cars, urban aircraft, and drones.

Engines still rely on old technology that’s inefficient and costly

Today’s solutions for power and energy are held back by a lack of technological innovation. Gasoline engines are inefficient, diesel engines are big and heavy, and electric power/batteries weigh a ton compared to what they produce. Just 6 gallons (36lbs) of fuel can displace 1,000 pounds of battery! These features present significant limitations to the range, payload, and efficiency current engines can achieve and increase operating costs.

A new efficient, lightweight, and environmentally -friendly engine design

LiquidPiston has developed a thermodynamic cycle which is 30% more efficient than the gasoline and diesel cycles used in almost all internal combustion engines today. This cycle, named the High-Efficiency Hybrid Cycle (HEHC), has been implemented into a compact, lightweight engine designed to be power-dense and multi-fuel capable.  The new design, dubbed the "X Engine", is a new take on the old rotary engine. It solves the challenges of prior generation Wankel rotary engines, while preserving key advantages of high power to weight, few parts and simplicity, with near-zero vibration.  Our design also cuts back on fuel consumption and corresponding CO2 emissions and the costs of running a traditional engine.

Above video: X-Mini SI engine cycle animation.  Our alternate diesel configuration is shown in this animation.   See more of LiquidPiston's videos here

With over $9M in Department of Defense contracts, we already have an established presence in the military space

We’ve targeted the military as an initial market for our engines and have secured a handful of major contracts:

  • We have successfully completed several phases of development with DARPA (totaling $6M), resulting in development of a 30kW Compression Ignition (CI) engine core that could be used for UAVs, generators, or other applications.

  • We shipped our first fielded prototype to the US Army:  a 2kWe Compact Artillery Power System (CAPS) generator set, which burns diesel/jet fuel and weighs approximately 30% of the weight of the generator currently deployed and used by the Army.  This unit has successfully powered the M777 Howitzer in initial field testing.

Left: prototype 2kWe hybrid JP8 military generator prototype, powered by the X-Mini rotary engine 

[Middle];  Right: go-kart powered by the X-Mini.

  • We secured 4 concept/feasibility studies with industrial firms during 2019, totaling $1.1M.  Three of these focus on aerospace applications, and could lead to significant follow-on development programs. 

  • We are a Finalist in the US Army xTechSearch 3.0 competition, for which we demonstrated a successful flight of a Class 2 (55lb) UAV powered by our X-Mini Engine burning jet fuel.


Above video:  Maiden flight on Jet-A fuel (similar to JP8).  This is a parallel hybrid demonstration, with 2kW of electric power + 3kW from the engine.  Next steps, we will attempt to demonstrate in-flight start/stop capability, with "quiet cruise" in electric-only mode. 

We are a technology company developing simple, compact engines that work efficiently using a patented thermodynamic cycle

LiquidPiston develops advanced rotary engines based on the company’s patented thermodynamic cycle and engine architecture. The X Engine’s few moving parts consist of a rotor and an eccentric shaft. Except for ancillary parts such as injectors, fuel pumps, and oil pumps, there are no other moving parts, making the X-Engine extremely simple and elegant.

Our engines efficiently burn fossil fuels, minimizing the wasted energy typically lost through cooling losses and engine exhaust, seen in other engine designs.   

We are positioning ourselves as a technology company, not an engine manufacturer. We are looking to license our technology to partners, while also offering technical engineering consulting services to custom design and develop application-specific engines for our partners and customers, which include engine manufacturers and systems integrators. 

Multiple billion-dollar potential market segments for our products

  • The global Internal Combustion Engine (ICE) market is over $400B annually.  Our market penetration approach starts with focus, and then expands more broadly. 

  • In the first phase, we are focusing on military and aerospace markets, whose propulsion and power generation segments represent large application opportunities for LiquidPiston.


  • In the second phase, we plan to enter industrial and commercial, marine, UAV, urban mobility, and automotive markets.

  • After launching in initial market sectors, we will assign teams of engineers to work with our customers to introduce new engine platforms for virtually any segment of the engine market.  We started with low volume, high price applications, and plan to enter broader markets as volume scales.

Our rotary engines are the first disruption to engine technology in over a century

To our knowledge, we are the only engine company in the world developing engines based on a new, optimized thermodynamic cycle.

Other companies are focused on incrementally improving cycles first commercialized in the late 1800s. Our engines offer size and weight advantages, with potential for significantly increased range and reduced CO2 emissions compared to gasoline and diesel powered vehicles.  Our technology can also be a key enabler for the broad adoption of electric vehicles.  When used in conjunction with electric propulsion in a hybrid configuration, the LPI engines allow more range for an EV, while using smaller, lighter, more cost effective batteries.  We are maintaining a sustainable competitive advantage based on our ever-increasing IP (patents & know-how) and being the knowledge base and “clearinghouse” of all learning associated with our core engine technology.

Cutting-edge engine and hybrid-electric power solutions and technological services

In addition to continuing to innovate the core engine technology platform, we have multiple potential revenue streams that include:

  • Custom engine and hybrid-power design, as a service

  • Licenses to OEMs/partners to manufacture engines based on LPI design and IP, resulting in a combination of upfront license and recurring royalty revenue

  • Supplying prototypes and providing technical support and application integration services to LPI OEMs/partners to help them support their customers

We intend to lead in engine innovation and scale our products to serve a range of markets

We intend to be the global leader in developing technologies and platforms to enable high fuel efficiency and power density in internal combustion engines. We currently have 51 patents (35 granted + 16 pending), a robust innovation pipeline, and a next-generation engine lab prototype which promises to increase power density significantly. Our engine platform is scalable and we intend to serve markets ranging from home and garden to electric vehicles and aircraft. Over the next 5 years, our goal is to target a high revenue/EBITDA growth trajectory.

Technology is scalable to 500+ hp

An experienced team dedicated to innovation

The team behind LiquidPiston is composed of leading innovators in computer science / AI, physics, math and engineering. Co-founders Alec and Nikolay Shkolnik have spent over a decade conducting R&D and developing patented technology to create the innovative thermodynamic system in the LiquidPiston engines.

Per Suneby, SVP of Corporate Development, is a seasoned clean-tech startup executive.  Chief Engineer Joe Pasciutti brings over 30 years of diverse technical leadership to the company, bringing new turbine engines from advance concept through production. As a whole, the team has the dedication and background to revolutionize next-generation engine development.

Investing in LiquidPiston is an opportunity to help change the energy-sustainability paradigm

Increasing energy use is directly correlated to rising standards of living, particularly in large, rapidly developing countries. If LiquidPiston were broadly deployed, we believe economic development could progress with a dramatically lower amount of fossil fuels used for vehicles power and for electric energy production compared to other engines and generators. In addition to offering environmental benefits, we believe our technology can be applied with economic and performance advantages in many markets, which will drive demand and allow LiquidPiston and our partners to command a premium price versus legacy engines. This investment opportunity features a capital-lite business strategy and leverages partners to serve many large application markets.

Above: LiquidPiston replaces the 40 lb / 6hp engine in a go kart with its 4 lb / 4hp X Mini engine.  Makes for a fun demo!

Above:  We were recently featured Season 31 Episode 9 of the Science Channel / Discovery Channel How It’s Made show!   Click here to view.

You have questions, we have answers

Q: How is the LiquidPiston X Engine different from the Wankel? 

A:   Click here for a detailed writeup!

In the Press

Small but growing number of CT startups turn to crowdfunding

So in 2016, he turned to Wefunder, an online business crowdfunding platform, hoping to tap the company's legions of followers as potential investors. The campaign was a hit, raising almost $1.3 million.

Unmanned Systems Technology Magazine, Dossier on LiquidPiston

Ian Bamsey investigates this new take on the rotary that challenges Wankel designs on efficiency and performance.

DARPA Looks to Extend Range of Drones, Autonomous Vehicles with LiquidPiston: CEO, Alexander Shkolnik

LiquidPiston is revolutionizing next-generation engine development. The company, headquartered in Bloomfield, Conn., develops and licenses compact & efficient power solutions based on an optimized thermodynamic cycle and a new type of rotary engine architecture.

Revolutionary Heavy-Fuel Engine For UAS Gets Darpa Boost

Development of a new type of rotary diesel engine that could provide compact, efficient and reliable heavy-fuel propulsion for smaller UAVs and other applications has been boosted by a $2.5 million Darpa contract

LiquidPiston: Could This Be The Engine Start-Up That Makes It?

NIkolay Shkolnik says LiquidPiston’s X Mini rotary engine can double fuel economy, eliminate noise and vibration and reduce the size of engines by 30% to 75%. Check out the video: a four pound X Mini replaces a 40 pound standard engine in this go kart.

LIquidPiston Unveils Tiny But Powerful Rotary Engine

Today it's for go-carts; tomorrow, it may be an electric car range extender

How a 4-Pound Engine Can Replace a 40-Pound Engine

Engine startup LiquidPiston has radically shrunk a go-kart engine, but it's the military applications that has everyone really excited.

Game-changing rotary engine muscles a go-kart

Imagine an engine that's 30 percent smaller than a traditional piston design of like output, and that runs smoothly, with less noise and vibration. Plus, it burns several types of fuel. That's the LiquidPiston X rotary engine, which was recently demonstrated powering a go-kart.

X marks the spot

Smaller, powerful X engine promises increased UAV flight endurance

LiquidPiston: Disrupting the curve with innovative custom power solutions

The internal combustion engine in its modern form has been around for more than 150 years. It’s a mature technology that treads the path of the traditional S curve. Which means that for some time now, companies have been spending billions of dollars for minor increases in performance. LiquidPiston,


LiquidPiston, a company that has designed a revolutionary new rotary engine, took home the top prize at AUVSI’s NOVUS Unmanned conference and competition in San Francisco.

Freedonia Group: Residential vs. Commercial Global Power Lawn & Garden Equipment Markets

While more than half of the $23 billion global power lawn and garden equipment market is accounted for by residential applications, residential demand is heavily concentrated in affluent markets such as the US. In low-income markets, commercial applications tend to be the larger driver of sales.

Offering Summary



LiquidPiston, Inc.

Corporate Address


1292a Blue Hills Ave., Bloomfield, CT 06002

Offering Minimum



Offering Maximum



Minimum Investment Amount

(per investor)




Offering Type



Security Name


Common Stock

Minimum Number of Shares Offered



Maximum Number of Shares Offered



Price per Share



Pre-Money Valuation



*Maximum Number of Shares Offered subject to adjustment for bonus shares. See Bonus info below

Perks* and Investment Incentives

Early Bird

First 48 hours - Friends and Family Early Birds | 15% bonus shares

Next 5 days - Early Bird Bonus | 10% bonus shares


$1,000 | Recieve a free LiquidPiston T-shirt (International investors will be asked to pay for shipping)

$25,000+ Invite to tour our shop + 10% bonus shares

$50,000+ Invite to Lunch with an LPI Founder (CEO or CTO) |15% bonus shares

*All perks occur after the offering is completed; travel associated with invite to LPI is at investor expense.

The 10% Bonus for StartEngine Shareholders

LiquidPiston, Inc. will offer 10% additional bonus shares for all investments that are committed by investors that are eligible for the StartEngine Crowdfunding Inc. OWNer's bonus.

This means eligible StartEngine shareholders will receive a 10% bonus for any shares they purchase in this offering. For example, if you buy 10 shares of common stock at $36.50 / share, you will receive 11 common stock share, meaning you'll own 11 shares for $365. Fractional shares will not be distributed and share bonuses will be determined by rounding down to the nearest whole share.

This 10% Bonus is only valid during the investors eligibility period. Investors eligible for this bonus will also have priority if they are on a waitlist to invest and the company surpasses its maximum funding goal. They will have the first opportunity to invest should room in the offering become available if prior investments are cancelled or fail.

Investors will only receive a single bonus, which will be the highest bonus rate they are eligible for.

Irregular Use of Proceeds

The Company might incur Irregular Use of Proceeds that may include but are not limited to the following over $10,000: Vendor payments. Salary payments made to one’s self, a friend or relative.

Show More
Most recent fiscal year-end:
Prior fiscal year-end:
Total Assets
$2,810,436.00 USD
$2,933,162.00 USD
Cash And Cash Equivalents
$2,082,830.00 USD
$2,347,993.00 USD
Accounts Receivable
$0.00 USD
$0.00 USD
Short Term Debt
$1,746,896.00 USD
$364,111.00 USD
Long Term Debt
$2,188,661.00 USD
$2,756,048.00 USD
Revenues And Sales
$2,840,294.00 USD
$3,281,381.00 USD
Costs Of Goods Sold
$0.00 USD
$0.00 USD
Taxes Paid
$0.00 USD
$0.00 USD
Net Income
-$949,708.00 USD
$137,474.00 USD


A crowdfunding investment involves risk. You should not invest any funds in this offering unless you can afford to lose your entire investment. In making an investment decision, investors must rely on their own examination of the issuer and the terms of the offering, including the merits and risks involved. These securities have not been recommended or approved by any federal or state securities commission or regulatory authority. Furthermore, these authorities have not passed upon the accuracy or adequacy of this document. The U.S. Securities and Exchange Commission does not pass upon the merits of any securities offered or the terms of the offering, nor does it pass upon the accuracy or completeness of any offering document or literature. These securities are offered under an exemption from registration; however, the U.S. Securities and Exchange Commission has not made an independent determination that these securities are exempt from registration.


Notice of Funds Disbursement

about 2 years ago

[The following is an automated notice from the StartEngine team].


As you might know, LiquidPiston has exceeded its minimum funding goal. When a company reaches its minimum on StartEngine, it's about to begin withdrawing funds. If you invested in LiquidPiston be on the lookout for an email that describes more about the disbursement process.

This campaign will continue to accept investments until its indicated closing date.

Thanks for funding the future.


Q1 2020 Update - LiquidPiston

over 2 years ago

Special Notice  – Corona Update

  • In light of Covid-19, LiquidPiston is taking appropriate steps with respect to maintaining employee health and reducing risk of contagion within the company, while also attempting to maintain full productivity.  We are monitoring the situation each day with guidance from the local, state and federal governments, and adjusting our plans and activities accordingly.    Some employees have begun working from home, and most of our conferences and in-person customer meetings have been cancelled and transitioned to virtual meetings where possible.






LPI Update to Investors


Dear LiquidPiston Investor,


It’s hard to believe that it’s almost the end of the 1st Quarter – a lot of activity for the Company during the past 3 months.


Highlights since our last update (December 2019) include:


  1. Product Development Update:
    • While most of our team has been busy on customer programs (conceptual design efforts, see below), there are two other key developments that have been enacted:
      1. Several of our concepts have pointed to potentially operating the X engine in a 2‑stroke configuration, rather than as a 4-stroke.   This means the engine would fire 6 times per rotor revolution (each of the 2 lobes of the rotor would go through the gas exchange / compression / fire / expansion phases, as it passes into each of the 3 chambers of the engine).   The X engine has unique capabilities to operate as a 2 stroke, potentially exceeding capabilities of typical 2-stroke piston engines.  I will provide more details of this with time, but for now wanted to share the exciting news that we adapted our X‑mini engine to demonstrate 2-stroke operability, and were able to achieve up to 85% improvement in indicated cycle firing power.   The engine was far from optimized (it was a rapid experiment just to prove to ourselves and our partners that 2-stroke is feasible), but it demonstrated a clear pathway to get 50%+ more power from our engine cores. The engine was run for over an hour with no hardware issues resulting from the 2-stroke operation. 
      2. We’ve developed a suite of software tools to assist in the rapid concept development of X-engines. This software tool is used to quickly size and scale single and multi-rotor X-engines for various applications.  We’ve taken and automated what used to be 4 months of work for an entire design team to just a week, which serves our core business strategy of serving multiple design efforts toward various applications and licensing the technology.

  2. Commercial Update:

We’ve been working on several feasibility / pilot programs funded by partners, looking at how the X Engine technology scales and could be adapted for partner-specific applications. 

  • We completed a project with a major aerospace company for auxiliary power application.  The program went well, and the LPI technology was shown to provide a major benefit over existing turbine-based technology, offering very significant fuel savings.  That partner is now evaluating go-forward options. We are continuing discussions with their technical team on near-term and long-term next steps, while their management deliberates on strategy and funding decisions.  
  • We are also finishing up a second aerospace concept study, in the Unmanned Aerial Systems (UAS) propulsion space.  We are engaging in initial discussions toward a potential Phase II project, potentially involving a 3rd party manufacturing partner.
  • We continue to explore manufacturing, licensing and distribution partnerships to commercialize the 2kWe hybrid generator (“CAPS” generator) and derivatives. The Army is anticipating a major modernization effort of its fleet of 25,000 two and three kW generators, and the LPI generator may be a good fit for this.  The generator needs to be matured in both technology and manufacturing readiness, and LPI is seeking funding and partnerships to help bridge to the Army requirements expected in 2022. 

Note:  We have strict Non-Disclosure Agreements in place, so we are necessarily restricted from disclosing partner names and project details.


C. US Government Activity:

Our involvement with the US DoD, particularly multiple program offices within the US Army is ramping up and we are getting good visibility from our CAPS project and participation in the Army xTechSearch 3.0 competition. (


Current status of US Government proposals and projects:

  • We are an Award Winner ($140K cash prizes) and finalist in the US Army xTechSearch 3.0 competition. Through the event, we have participated in the XTechSearch accelerator program events, meeting with industry and government leaders in Austin, Boston, and Washington DC.  The Finals of the competition were slated to be held at the AUSA Global Force Symposium in Huntsville, AL this week, but this event has been postponed due to the Corona virus.  For the competition, we demonstrated our UAS using our X-Mini Engine on Jet fuel in a parallel hybrid-electric configuration (see video from the last update).  In recent testing, we further demonstrated capability of in-flight engine-stop and restart, while the vehicle cruised on electric-only (“quiet”) power. To our knowledge, this is an industry-first capability for UAVs on Jet fuel. 
  • We have been notified of selection for award of a US Army SBIR contract for the preliminary design of a Hybrid-Electric X-Engine (HEXE) Propulsion System for UAS applications.  This work builds on the above referenced UAV work, increasing the system capability to demonstrate VTOL capability, and ultimately providing a rugged UAV propulsion system to support Army UAVs. It starts as a $100K Phase I, and has the potential to evolve to a $1M Phase II program. 
  • We have several other proposals and whitepapers being evaluated by multiple divisions within the Army, the Air Force, and 1 with the DOE, ranging from portable ground generators to aircraft auxiliary power to hybrid electric propulsion for manned aircraft.

D. Fundraising Update:

  • As you know - LiquidPiston embarked on a crowdfunding campaign with StartEngine in January, which was extraordinarily successful.  We raised the maximum allowed under Reg CF ($1.07M) in just 9 hours, which was probably a record for the industry.   This gratifying as it indicates that a lot of people are following the Company and believe in our mission of disrupting the combustion engine as we know it - with significantly reduced size, weight, reduction in fuel consumption,  resulting CO2 impact as well as other greenhouse gases.   We were also fortunate to have been evaluated by and featured by Neil Patel and the Angels and Entrepreneurs Network:
  • As numerous individuals continue to contact us directly inquiring about the possibility of investing in the Company, we are currently accepting accredited investors for direct investment (minimum $25K). If interested please contact    

As always, please do not hesitate to contact me if you have any follow-up questions.  


Thank you again for your support as LiquidPiston moves into the next phase of productization, industrialization and company-building.




Alec Shkolnik, PhD
 President and CEO





Campaign wrap up

over 2 years ago

Thank you everyone for the amazing support. We maxed out with $1.07M in just 9 hours!  Epic! 

Looking forward to a great 2020.  For those on the waitlist please stay tuned. 

Over $400K raised in just the first few hours !

over 2 years ago

Hello everyone - we are blown away by the response to our campaign.  Over 300 investors so far, and over $400K raised in just a few hours.  

We are grateful and appreciative of the support !! 

- Alec Shkolnik & the LiquidPiston team 

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