Company Profile (AI Text)
Name: LiquidPiston
Canonical URL: https://wefunder.com/liquidpiston
Updated at: 2026-06-15T05:00:06Z

Tagline: First wholly new combustion engine / cycle in 85+ years
Elevator pitch: Engines are dirty, and physics tells us we can do better! We've developed an optimized thermodynamic cycle and built a fundamentally new combustion engine that's cleaner, cheaper, quieter, and smaller. Compared to piston engines, our "X" rotary engine can be ~5-10x smaller and lighter than a Diesel, and up to 2x more efficient than a gasoline engine. An electric vehicle using LiquidPiston combined with a small battery pack could have a lower CO2 footprint compared to plug-in electric vehicles.

Key claims:
- Total raised on Wefunder: 2188466 | citation: https://wefunder.com/liquidpiston#claim-total-raised
- Total investors: 1095 | citation: https://wefunder.com/liquidpiston#claim-total-investors

Verified facts:
- Total raised on Wefunder: 2188466 | observed_at: 2026-06-15T05:00:06Z | expires_at: 2026-06-16T05:00:06Z
- Total investors: 1095 | observed_at: 2026-06-15T05:00:06Z | expires_at: 2026-06-16T05:00:06Z

Computed metrics:
- total_amount_raised: 2188466
- total_investors: 1095
- team_size: 3
- featured_investor_count: 0
- faq_count: 5
- recent_post_count: 0

Quick facts:
- Raised $1.29M from 727 investors on Wefunder in 2017.  | citation: https://wefunder.com/liquidpiston#claim-fact-1
- Since then, DARPA awarded a Phase 2 $2.5M development contract in October 2017, a follow-on to our 2 DoD contracts, totaling $5.5M in non-dilutive funding.  | citation: https://wefunder.com/liquidpiston#claim-fact-2
- New engine architecture could improve fuel efficiency by up to 2x over a gasoline engine while reducing size and weight by up to 10x over a diesel engine. | citation: https://wefunder.com/liquidpiston#claim-fact-3
- 45 patents issued or pending in the U.S. and internationally. | citation: https://wefunder.com/liquidpiston#claim-fact-4
- Our 70cc "X mini" engine is a 3-5hp gasoline engine the size of a honeydew melon. Measured 50% increased efficiency over comparable per-cylinder displacement gasoline engine. The engine is being inserted into a 2kwe hybrid electric generator for A | citation: https://wefunder.com/liquidpiston#claim-fact-5
- Our 750cc "X-4" engine is a 40hp rotary Diesel X engine "Alpha" prototype, which ultimately may fit in an 11" box while weighing just 40 pounds. We are proving it's efficiency and power. | citation: https://wefunder.com/liquidpiston#claim-fact-6
- Completed $1M "seedling" program with DARPA in 2015. | citation: https://wefunder.com/liquidpiston#claim-fact-7
- $460 billion total addressable market; starting with military industry and handheld engine. | citation: https://wefunder.com/liquidpiston#claim-fact-8

FAQ:
- Q: Can you explain, in a nutshell, how you're different than the failed Wankel rotary engine? Also is your valuation based upon your "potential" military contracts, or something else as it does seem quite high for a seed round investment stage. Thank you!
  A: Thank you for these questions. For difference between a Wankel, please have a look at: http://liquidpiston.com/wp-content/uploads/2014/11/Wankel.png 1) we have high compression ratio, constant volume combustion and over-expansion - thermodynamically much more efficient. The Wankel engine uses standard Otto (spark ignited gasoline) cycle, whereas we are an optimized Diesel. 2) The Wankel is an engineering beauty - simple and elegant, low vibration and high power density - BUT - it was always p...
- Q: Hi Guys, I saw you featured on Jalopnik a few months ago. Very cool. Interesting that you all bring up the challenge of bringing fuel to the front lines in the military application, and military being your market entry point. Earl Energy, out of Virginia/Maryland area, is foun...
  A: Hello - thank you for the pointer to Earl. We are currently looking for partnerships with established manufacturers / suppliers that specialize in military equipment. We will release some news shortly about two recently signed defense contracts, which include partnering with two large Primes that currently produce a variety of military systems including generators and hybrid applications.
- Q: What are the challenges around the seals between chambers? Have you solved them or is more work necessary? Is seal material similar to Wankel, or significantly different?
  A: Seals have traditionally been a challenge of the Wankel Rotary engine. The first issue is significant blowby that stems from a) leakage pathways at the interface at the corners between the apex seal and the face seal; also b) the apex seals crossing the spark plugs; and also c) the apex seals "chatter" as they are moving at high speeds against the housing. Also, the seals are a challenge to lubricate - oil must be sprayed into the charge, and most of this oil burns, while only a fraction goes...
- Q: What is the emissions profile and how will this be addressed?
  A: We have been focused to-date on engine performance - power and efficiency, and getting the engine to a state where we can power an application (see go-kart video). We have not started work on emissions. In principal, we have addressed the major hurdles the Wankel engine faced in regards to emissions (by having an optimized spherical combustion chamber; and by direct lubrication of the seals, avoiding burning of oil). We also have a longer duration / constant-volume combustion process - with m...
- Q: How will the continuing improvement in battery technology impact the need for internal combustion engines generally, and more specifically how will that impact the need for your product?
  A: That's a great question. In some cases, our technology is complementary with a battery. Consider a range-extended electric vehicle as an example. Customers are used to 300 miles of range; they want the ability to rapidly refuel/recharge; and they want low cost of ownership. We also want to reduce the CO2 footprint of the vehicle. In an all-electric solution, typically a battery has to make several trips around the world before it makes its way to a vehicle (though Tesla is trying to change th...