Engine Options

Power Your Sonex Aircraft!

Sonex, LLC approves several different engines for its airframes, and offers firewall-forward support for those engine options, ranging from engine mounts and cowlings, to complete installation manuals:

AeroVee | Jabiru | UL Power | Rotax 912

AeroVee Engines

Sonex Aircraft were originally designed to utilize the AeroConversions AeroVee or similar engines, and the AeroVee is the most-popular engine choice for Sonex builders. The AeroVee is a complete VW Conversion Engine Kit Package offered in 80 hp and turbocharged 100 hp versions, by AeroConversions, a product line of Sonex, LLC.

The AeroVee Engine Kit continues the Sonex Aircraft tradition of simple, elegant design. A 2180 cc aero-engine that can be run on 100LL or auto fuel, all of the supplied components are brand-new, zero-time parts.

The AeroVee comes as a complete kit that you can assemble yourself in approximately 12 hours, with the aid of an AeroVee Assembly and Installation Manual and an instructional DVD, along with free Phone/Email Technical Support. The AeroVee DVD is available for purchase separate from the engine kit for those that wish to preview the project.

The AeroVee engine kit also includes the AeroConversions AeroInjector.


AeroVee 2.1 80hp: $8,900
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Read More about the AeroVee


AeroVee Turbo 100hp: $12,500
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Read More about the AeroVee Turbo

For More detailed information about the AeroVee, visit www.AeroConversions.com
Download: AeroVee Assembly and Installation Manual


AeroVee | Jabiru | UL Power | Rotax 912

Jabiru Engines

Sonex Aircraft has worked with Jabiru Engines for many years. In particular, the 120 hp Jabiru 3300 has become a very popular engine choice for our aircraft, making-up approximately one third of the worldwide fleet of flying Sonex Aircraft. Sonex Aircraft offers engine mounts for Jabiru 3300 engines (Jabiru 2200 mounts available for Legacy Sonex and Waiex aircraft), and our Sonex/Jabiru Cooling Baffle Kit and Installation Guide is available from our AeroConversions product line.

Sonex highly recommends the AeroConversions AeroInjector to replace the Jabiru-supplied Bing carb. Read more about the AeroInjector's advantages in "The $35 Hamburger!"

Jabiru Engines are sold and supported by Arion Aircraft.



AeroVee | Jabiru | UL Power | Rotax 912

UL Power Aero Engines

ULPower Engines have been developed specifically for use in light aircraft and are manufactured to the highest standards with fully electronic ignition and multi-point fuel injection (FADEC) system as standard equipment.

ULPower Engines feature dual electronic ignition (with variable timing), excellent power-to-weight ratio, and high fuel efficiency in a conventional configuration: Air-cooled, direct drive, horizontally opposed 4-cylinder.

All ULPower engines fly on avgas and auto fuel — even with mixtures up to 15% ethanol — and can be upgraded with back-up and safety systems.

Sonex Aircraft provides UL Power 260 and 350-series engine mount options for the new Sonex-B, Waiex-B, and Xenos-B models, and B-Model cowlings have been designed to accommodate UL Power 4-cylinder engines using UL Power's 110mm length prop hub with SAE-1 flange.

UL Power LLC (US Dealer) has 3rd party support available for UL Power engine mounts to fit Legacy Sonex, Waiex and Xenos airframes and for Onex airframes. The Jabiru 2200 engine mount offered for Legacy Sonex Aircraft will fit UL260-series engines.

UL Power 260 and 350-series engines may be purchased from Sonex Aircraft, and technical support is offered by UL Power LLC. Engine packages include Exhaust, Baffle Kit, Alternator and Primary Fuel Pump.

*Note: All published prices subject to change with the USD to Euro exchange rate. Prices will be verified with UL Power and, if necessary, re-quoted upon receipt of your order.


UL350i 118hp: $25,070*
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Read More about the UL350i


UL350iS 130hp: $26,160*
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UL Power Installation Accessory Kit
Kit Includes:
  • Auxiliary Fuel Pump Kit - p/n K0300002: Qty 1
  • Fuel Connection Kit - p/n K0200001R: Qty 1
  • Oil Thermostat - p/n E042515: Qty 1
  • Oil Filter Adapter Screw - p/n E042007: Qty 1
  • Copper Sealing Ring - p/n S3202615: Qty 3
  • Adapter - p/n F2560014: Qty 2
  • Extension Connection Oil Thermostat - p/n SE042520: Qty 1
AeroConversions Accessories


AeroVee | Jabiru | UL Power | Rotax 912

Rotax 912-Series Engines

Rotax 912-series engines have become popular with some Sonex builders, particularly in international markets such as Europe and South America, and several customers have successfully made their own Rotax installations.

Although we do not sell Rotax engines, Sonex Aircraft provides Rotax 912-series engine mount options for the new line of B-Model aircraft, and B-Model cowlings have been designed to accomodate Rotax engines. Rotax 912-series engine mounts are also newly available for Legacy Sonex Aircraft. Sonex does not provide specific installation techical support for Rotax engines as there are many existing Rotax installation support sources already available.

Be sure to see our FAQ page for Rotax installation considerations.

Rotax 912-series Engines


AeroVee | Jabiru | UL Power | Rotax 912

A note about alternative engine choices: Although there may be other viable engine choices for Sonex, LLC airframes, only approved engine installations have been engineered for proper weight and balance and power loading. Specific firewall-forward installation support is only offered for engines installed and tested by Sonex, LLC. When installed according to Sonex-provided documentation, the user of an approved engine can anticipate a trouble-free installation proven by thousands of flight hours, as well as full customer support and on-going serviceability.

Customers should not underestimate the vast amounts of time, money, and effort that go into alternative engine development and installation. Any customer choosing to use an unsupported engine installations are true "experimenters". Sonex, LLC will not offer firewall-forward technical support for unapproved engine installations. Your choice of an alternative engine may also result in insurability problems. As a potential builder, you must educate yourself on the true impact of your engine choice before embarking on an alternative engine installation. The list of issues that should be considered include but are not limited to: Installation support (cowl, engine mount, cooling), installed weight, reliability, serviceability, impact on flight qualities and useful load of airframe, and availability/cost of insurance. Sonex Aircraft engine installations must not exceed 200 lbs total weight forward of the firewall. Any builder considering use of a heavier installation should take notice of the important information contained in our Gross Weight Advisory (LSA Compliance and Safety) Letter.

Sonex staff have been involved in the aircraft and engine business for over 40 years and we are constantly watching the engine market for emerging products. If a new, viable powerplant emerges which fits our needs and philosophy it will be offered only after it has been thoroughly tested on factory aircraft. If you have any questions about your engine choice, please feel free to contact us.

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