FAQ

1. Is the engine currently available for purchase?
LiquidPiston’s engines are in development and are not currently available for purchase.
2. How does the engine differ from a Wankel?
While it is a rotary engine, LiquidPiston’s X Engine is NOT a Wankel engine. It has a fundamentally different architecture and operation.

Wankel
3. Are you hiring?
LiquidPiston has a leading team of experts focused on rotary engine development. We are always interested in exceptional people. Please explore our job postings, here. If you would like to apply for one of the open positions, or to let us know how you can make a difference at LiquidPiston, please email your resume to hr@liquidpiston.com.
4. How can my company partner with LiquidPiston?
LiquidPiston is interested in speaking with potential industry partners regarding licensing the engine for specific market applications that require compact, lightweight, quiet, low-vibration, powerful, fuel-efficient engines. Ideal partners are current engine developers and manufacturers that are looking to expand their product lines.

While we appreciate all of the interest we have received from folks that volunteer to test engine prototypes in various applications, we are not currently looking for help in this area.

If you’re interested in discussing a partnership with LiquidPiston, please contact us.
5. What is the status of the engine development?
6. What is the rated HP?
LiquidPiston has developed engine prototypes that range from 3 to 70HP:

• X Mini: 70 cc (3-5 HP) Gasoline Spark Ignition HEHC engine
• X1: 70 HP Diesel Compression Ignition HEHC engine
• X2: 40 HP Diesel Compression Ignition HEHC engine
7. Is the engine scalable?
LiquidPiston’s engine technology can scale much like a piston engine, to serve applications down to 1HP, and to over 1000 HP. Methods for scaling include: 1) changing the diameter of the rotor; 2) changing the width of the rotor; or 3) adding more rotors.
8. What is the RPM range?
For smaller engines, the RPM range is from 1000 to 14,000. For larger engines, the RPM range is 500 to 5,600.
9. What is the compression ratio?
For the X Mini 70cc gasoline prototype, the compression ratio is 9.2.

The diesel prototypes have operated at either 14:1 or 18:1 and should be able to go higher, to 25 or more.
10. Are there any torque curves available?
The engines have been run at a few operating points (loads and RPM). We do not have full power or torque curves available as of yet.
11. What is the percentage of exhaust gas recovery (EGR) that occurs during normal operation?
There is no controlled EGR. There is some hot exhaust gas residual.
12. Does the engine require side seals?
Yes, like any rotary engine. The difference in the X engine is the side seals can be lubricated through access points in the cover, which is a unique feature of this engine.
13. What is the difference between X1/X2 and X Mini?
The X1 and X2 are compression ignition diesel engines, while the X Mini is a spark ignition gasoline engine.

The X1 and X2 are designed for 70 and 40 HP, while the X Mini is designed for 70cc, 5 HP.
14. Can the X Mini engine be powered by natural gas (NG)?
Yes. Many gasoline engines can be converted to run on natural gas, including the X Mini. A natural gas X Mini would still be a spark ignited (SI) engine.
15. How long would it take to design and build an X-style engine in a particular power range?
It depends on the required power: The design, fabrication and testing of the X Mini 70 cc gasoline engine has taken approximately 1 year. The larger the engine, the longer it will take.