The ULPower
Family of Engines
The 350iS model is a higher compression
version of the 350i.
Racing roots offer modern technology
BY TIM KERN
COMPUTERIZED OR DIGITAL ENGINE control has been available for
years on turbine engines and has been gradually entering the general
aviation scene over the last several years. This technology, often
referred to as full authority digital engine control (FADEC), into the
sport aviation arena is growing. One example of this technologically
advanced power option is found in the UL260i aero engine, manufactured by ULPower Aero Engines of Belgium.
The UL260i engine made its debut in the United States at the U.S.
Sport Aviation Expo in January 2007, with then company owner
John Pescod quietly extolling the engine’s virtues. Its dedicated aero
design gave it a familiar look, and its modern approach to fuel, spark,
construction, and packaging made it cutting edge. Since then, a lot of
work and progress have brought this engine into serious consideration for powering our aircraft.
ULPower’s design goals were to develop a powerplant offering
modern engine management (FADEC), light weight, low rpm direct
drive, and the ability to run on either unleaded mogas or avgas. The
founding partners of ULPower combined many years of engine
design, development, and manufacturing in the competitive automotive racing arena—they have a long history of success in grueling
off-road races such as The Dakar Rally (formerly The Paris-Dakar
Rally)—along with a proprietary engine control unit (ECU) to
develop a successful aviation engine.
The UL260i is a compact engine that provides an all-up operational weight (ready to run) in league with the market-leading Rotax
9-series engines at 160 pounds. This provides a respectable weight-to-power ratio of 1. 67, meaning that for every 1. 67 pounds of engine
weight, you have 1 hp available.
The layout is conventional and based on
a boxer engine: four opposed, air-cooled cylinders fed through two valves per cylinder
and operated by a single cam and solid lifters, with a five mainbearing billet crankshaft
directly driving the prop through a hub.
Electronic fuel injection and variable-timing
electronic ignition (with a built-in rpm limiter) respond in FADEC fashion to provide
single-lever power. The aluminum castings
provide a strong case, a deep sump, and a
compact shape. Billet cylinders, heads, and
other parts look clean while maintaining
predictable and close outside tolerances, and
the cast pistons and forged rods provide
strength and durability. The outside dimensions of the engine fit within those of the
Rotax 912 series or the Continental O-200.
In contrast to the liquid-cooled Rotax, there
is no external water radiator.
Since its introduction as a 2600-cc
engine, the 95-hp UL260i has gained a lon-ger-stroke bigger brother that adds 18
pounds and 23 hp but maintains the same
outside dimensions; the UL350i is now the
company’s best-selling model. Both the 260i
and 350i also come in higher-compression
“S” models: the UL260iS is rated at 107 hp,
