Jay,

When doing aerobatics, there are major gyroscopic forces applied to the
crankshaft where the propeller bolts on. (the flange)

This flange is heavy and therefore engine manufactures routinely have
"lightening" holes drilled into them to make them lighter and save
weight overall on the aircraft. Since aerobatic maneuvers cause alot of
(gyroscopic) stress in this area, cracks and / or flange failure can
occur. In order to strengthen this area, at the expense of adding
weight to the aircraft, the AEIO engines have solid flanges without any
lightening holes.

Depending on the type of aerobatics you do, and the type of propeller
you have installed on your aircraft, this becomes more critical.

For instance, in general terms, if a pilot flies "light" aerobatics with
a lightweight wooden prop, a solid flange isn't as important since low
gyroscopic stresses are imposed on the crankshaft flange. However, an
aerobatic pilot that performs maneuvers that create a large amount of
gyroscopic stress, and has a heavier, metal type prop on his plane, a
solid flange would be a must. You have probably noticed that most
airshow performers, and advanced and above competition pilots are using
solid flanges along with lightweight props such as the MT propeller.

As far as the inverted oil system goes, there are different ways to
"plumb" the Christen inverted oil system. Some methods allow better oil
flow in both directions than others. The ideal way to plumb the oil
system is so that oil can be picked up readily in all attitudes of
flight and returned back efficiently to the oil sump when upright.

This involves a whole different discussion once you have the basics of
how the Christen inverted oil system works.

Hope this helps,

BJ


Jay Moreland wrote:

What benefits does a solid flange crankshaft have? Please explain it
in a way that a complete neophyte like myself would understand. I
thought that the AEIO also has some internal holes that help the oil
move to critical areas better. Can you tell me specifically what kind
of aerobatic capabilities or safety factors this gives one, compared
with an IO-360 with a Christen inverted oil? Specifically, would heavy
inverted flight or Advanced or Unlimited flight not be advisable? If
not, why not?

I mainly would just like to learn more about these engines. Can you
give me any web or book references that would answer these types of
questions?
Jay

B. Jensen wrote:

An AEIO-360 has a solid flange crankshaft.
BJ

Jay Moreland wrote:

I need to have someone explain to me the advantages of two different
Aerobatic engines: IO-360 with Christen Inverted Oil system VS an
AEIO-360. Are there any inherent benefits of one over the other when
doing acro with negative G maneuvers? Or are they essentially the
same? Can you take any Lycoming IO model (320 or greater) and put on
a Christen system and have it work well?