February 2003 - American Bonanza Society

Venture #1, known as "The Flying Egg." is still running
fine with 7 500 hours on it. It has not received
any major component replacements despite
being flown in very rigorous fashion.
induction system. This induction system was placed
atop the cylinders because the little homebuilt had a
retractable nose gear. A Venture subsequently flew the
circuit at Reno at an average of 335 knots.
Mr. Minnis conceived the idea of STCing the
engine into other applications. Even though the Venture
homebuilt project eventually ended, the Atlantic Aero
folks thought the engine would make a great conversion
product for production singles. About four years ago,
they obtained an STC for the Cessna 210.
About an hour after arriving, I got to see the
exhaust manifolds. They were as advertised, stainless
steel and curved to reduce back pressure as compared to
the stock versions. They are already STC'd for
Bonanzas. But I couldn't get too excited over exhausts
after seeing the major changes being wrought on the
little A36 sitting among the Citations and Lears.
We went about our business that weekend, but I
really wanted another look at that prototype A36. My
John Ackerman. vice president of technical services of Allantic Aero, with
the BonanzQ testbed airplane.
excuse came when some friends wanted a ride to
Greensboro to pick up some Christmas puppies. My
spouse really gave me a hard time about using a puppy
delivery as an excuse to fly somewhere. But I had my
hidden motive: I wanted to see that modification again.
I revisited Atlantic Aero on a rainy, overcast day in
December to see the completed cowls on the test
airplane. After I shot an lLS through an approaching
warm front, Mr. Ackerman again escorted me to the
Bonanza, sitting outside with new cowl and nose fitted,
but not painted. The workmanship seems excellent.
They knew that Bonanza owners value the ability
to open our double cowls and view the engine for
preflight, so they fashioned carbon fiber upper doors
similar to the stock A36. They even used the same
convenient fasteners.
To clear the tuned induction system, the spine for
cowl door hinges that runs lengthwise from firewall to
nose bowl is raised slightly higher than the stock version.
This and the redesigned carbon fiber nose give the
front of the aircraft a less tapered look. The nose is reconfigured
to decrease drag, but maximize cooling. The
upper deck of the engine compartment becomes pressurized
in flight and creates a ram air effect into the tuned
induction system, giving about one-inch increased manifold
pressure above those usually seen.
The Hartzell Super Scimitar propeller sits extended
about 3.25 inches forward of a stock position. The
engine is about the same weight as the 550 and 520.
However, this engine is certificated to produce no less
than 317 hp.
Mr. Ackerman said that this airplane had
carried three adults, including the editor of AOPA Pifo/,
plus luggage and camera equipment to Long Beach,
California. averaging 181 knots true airspeed. Since
that trip, some of the older antennaes have been
removed and he says they see 181 knots true airspeed
on a standard day. These speeds, he emphasizes, are
without retrimming the airplane, i.e. they are the product
of the engine change, prop and cowling. He also
feels that the change in configuration "pulls the nose
over," i.e. the lower nose attitude is also helping with
increased airspeed.
I asked what the true airspeeds were before the
conversion. He told me the Bonanza was 164 knots on
its "best" day. His estimate is a "fair" increase of 15-16
knots on some aircraft, and as much as 20 knots
increased airspeed on others.
The cowl configuration and upper deck induction
system relate to a manifold pressure of 21 inches at
8,000 feet altitude. There is an alternate air door that, in
the case of icing, opens automatically and draws hot air
from under the engine.
Page 7682
ABS February 2003