V Aircraft Engines V300T--The Smoothest Piston Engine
Ever?
Imagine that someone offered
you a new engine for your GA bird... one that would burn MoGas as
well as AvGas, run as smooth as a turbine, and operate more quietly
than anything in it's class... and oh yes, offer significant fuel
savings over an equivalent powerplant (on the order of 25%).
Would you want it? Heck, Yes!
Would you believe they had one? Heck no... until now.
ANN has had the coveted opportunity to spend nearly an hour
behind the current engineering prototype of the 300 HP V300T, a
six-cylinder, liquid-cooled NEW generation GA powerplant that is
the product of a "clean-sheet of paper" design study. We have a
feeling it's not only going to find some fast fans for its
operating attributes... but for its operating economics as
well.
As previously noted in the first articles ANN wrote about this
new series of powerplants, we described the V Aircraft series as...
a 120 degree V-6, with a 4-main, straight-pin crank (two rods on
each throw). It sports a dry sump design that uses about 2 gallons
of oil. That oil is water-cooled, as is the entire engine. The
bores in the aluminum-alloy block are Nikasil-coated. There's a
single, chain-driven, overhead cam in each bank. One end of the
crankshaft sports a unique flywheel; the other has a torsion bar
extension, that goes to the 3:1 (108-36) gearbox. The fuel
injection, a main component of the FADEC engine management system,
offers clean firing, and doesn't have a venturi to help build up
ice.
The V-6 will hang from special rubber/close metal mounts. The
close metal design should stay relatively tight, in the event of an
engine room fire, keeping added stress on the engine mounts to
lower levels than conventional (1940s) designs.
The redundant EMS (Engine Management Systems) have a number of
fully-redundant systems within them. Even in the event of failures,
the redundant systems will still check one channel of manifold
pressure, ambient pressure, rpm, and throttle setting. The EMS
units also feature continuous data recording, so the entire history
of the engine's life can be seen at the end of any flight. (Those
who rent their airplanes to others, or members of
fractional-ownership groups especially, should love that feature.)
The EMS features an adaptive knock control -- it's a great way to
keep the engine optimized, even as gasoline blends change -- or
when you're using car gas, which is blended for the region where
it's sold.
There's plenty of spark assured: you'll notice six double
ignition coils.
Adding to the electrical redundancy are two 75-watt alternators.
Everything with a wire on it, or a signal running through it, is
duplicated. When we looked for the two ECUs, though, we couldn't
find but one box. That's right -- the box is a mechanical item;
rest assured, there's two ECUs in there, each with its separate
wiring.
The ECU (the timing unit) has both camshaft and crankshaft speed
and position sensors, for redundancy. It's a total dual-lane design
-- two of everything; plus it carries a package of spare "maps," in
case the sensors fail. For folks who still don't trust such things,
and to add to the redundancy, there's an auto/manual,
pilot-controlled select. If things really go phooie, there's still
a fall-back, "limp-home" mode available; it is automatically
employed.
ANN's Jim Campbell had to run to catch a flight for the NW EAA
show in Arlington, Washington... but before he did so, he filed
these enthusiastic comments.
"The current rendition of the V300T may be the smoothest piston
engine I've ever flown... so smooth that when you put the hammer
down, there is the perception of a lack of power... because we have
SO come to associate MORE power with MORE noise and MORE vibration.
This is the first time that I've ever flown a piston engine where a
notable indicator of increased power application came from the
noise of the airflow around the aircraft rather than from the
engine itself -- think about that... The engine is turbine smooth,
with very low noise levels, and tremendous power. Watching a Murphy
Super Rebel climb at upwards of 1000 fpm (and without full power)
while still doing the better part of 100 knots (on a VERY hot day)
is a stark indicator that something thrusty is happening underneath
the cowling."
"A 21st century piston engine for 21st century airplanes is the
concept behind the massive R&D effort that produced the
normally aspirated V220 and the turbo-charged V300T and while there
is yet a bit more than a year to go before we see these things show
up in a hot new GA production aircraft (where it will be sold to
OEMs as a full-firewall forward package, sans only prop), our
doubts are turning into enthusiasm. We flew it... nothing that
smooth, with that power, happens by accident... not for over an
hour and on a day when the temps are pushing 100 degrees."
"Initial fuel readings were an eye opener... with a solid 75%
percent of rated power in use, the Super Rebel was consuming
11.0-11.2 GPH... if these numbers hold (with truly equivalent power
to other 300 HP mills), this kind of consumption is going to win
some new friends... especially when gassing up from the much
cheaper MoGas pump (and by the way, you CAN mix and match MoGas and
AvGas in the same tanks... no sweat)."
ANN will have more to say about this mill over the next few
weeks and will be spending considerable time with the staff of V
Aircraft Engines (the once-Bombardier division that is handling the
development of this baby). We've seen amazing progress in the way
we build our airplanes, the way we make them safer and the panels
we install in them... and the long-awaited, final piece of the
puzzle -- a truly new generation of powerplants, appears (finally)
to be in the offing. Stay tuned...