REFLECTOR: From IVO

Sun Jun 27 20:32:17 CDT 2004

How about some truth in reporting?

A minor nitpick, their website says 700 horsepower, not 720.
Now, I would be very cautious about this claim, because we all know about
the history of the IVO.  However, suppose that IVO prop were mounted on a
turbine engine?  Would it take 700 horspower?  Perhaps.  Someone should ask
IVO for the engineering data on this application ... a responsible thing
every builder should do.  It appears as though you were one of the
responsible builders.  You asked if their product could be used on a TSIO520
in pusher configuration, and the response was "no".

It looks like the TSIO520 is good for 310(285 from other sources) horsepower
at 2700 RPM.  The MTV-18V electric prop weighs 45lbs and can take a max
260HP at 2800RPM.  It's not big enough for your engine.
The MTV-23 prop weighs 55lbs, and can take 350HP at 2700 RPM.

I could not find any information on the MT regarding specific operating
limitations, although it does address them, it does not say which engines
are affected.  Likewise, the IVO site does not say which engines have
operating limitations with their prop.  As a side note, I did find this
interesting: http://www.mt-propeller.com/pdf/manuals/e-118.pdf.  For
overspeed limitations their chart for piston engines start at 110% RPM
whereas the turbine engine graph starts at 120% max RPM.  So even MT
acknowleges a difference in engines.  The point I'm getting to is that it's
about power pulses and resonant vibrations being the problem, not Maximum
absolute horsepower.

The IVO weighs in at 26.7 lbs.  Almost half of the MTV-18.  Beef up the IVO
until it weighed similar to the MT, and it *may* perform equally.  But it
doesn't weigh as much, so it most likely compromises on structural integrity
at the higher torsional forces.

I feel that the MT has real engineering, and real test cell data behind it.
I saw a WWI documentary, and saw some footage from a factory and swore the
logo on the props were identical to the MT logo, but their site says they
have been in business since 1981.  I also can't help noting that they like
to blow their own horn as well with the following: "mt-propeller Entwicklung
GmbH is specialized in the development, design and manufacture of variable
and fixed pitch propellers for engines producing up to 4500 hp."  Now, I'd
like to see a piston engine at 4500HP not break a few propellers before they
get it right.

The 700HP IVO, and the 4500HP MT are most likely maximum engineering limits,
and not flying examples.  I have no information either way.

So, I'll get off my soapbox about here and say that starting a flamewar over
XXX product is rediculous.  I've seen the performance of IVO, and MT on two
Velocities.  Both Franklin, both retract, only difference is one is a 173.
Both props have performed up to now flawlessly.  Would I like an MT?  You
bet.  Would I pay for one?  No.  I would pay $5,000 for one.  That's what I
think it's worth.  I'll go with the IVO, because I've seen it work on
similar installations, and IVO blesses this combination.  In parting, one
last quote from the MT site(
http://www.mt-propeller.com/pdf/manuals/e-118.pdf ):

People who fly should recognize that various types of risks are
involved; and they should take all precautions to minimize them,
since they can not be eliminated entirely. The propeller is a vital
component of the aircraft.
...
It is essential that the propeller is always properly maintained
according to the recommended service procedures and that a
close watch is exercised to detect impending problems
before they become serious. Any grease or oil leakage,
unusual vibration, or unusual behavior during operation
should be investigated and repaired as it could be a warning
that something serious is wrong.
Gerd R. Muhlbauer
President
MT-Propeller Entwicklung GmbH

This holds true for any equipment on our aircraft.
Okay, flame away.

 Brian Michalk  <http://www.michalk.com>
Life is what you make of it ... never wish you had done something.
Aviator, experimental aircraft builder, motorcyclist, SCUBA diver
musician, home-brewer, entrepreneur and barely single

> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org]On
> Behalf Of Scott Derrick
> Sent: Sunday, June 27, 2004 8:43 AM
> To: Velocity Aircraft Owners and Builders list
> Subject: REFLECTOR: From IVO
>
>
> I sent IVO a request about their claim on their website that they made
> props for up to 720 HP.  Here's  their response.
>
> Sounds like they can't handle anything but the weenie ultra light
> motors to me.
>
>
> Dear Sir,
> We will not be putting anymore Ivoprops on Lycoming powered aircraft.
> nor Cadillac direct drive, Continental O360, O470, O520, 0540, DeltaHawk,
> Jabiru 8 cylinder, Limbach, LOM, and M14P engines due to pulses
> and harmonics.
> Regards, www.ivoprop.com
>
>  >From: "Scott Derrick" <scott at tnstaafl.net>
>  >To: <ivoprop at pacbell.net>
>  >Sent: Saturday, June 26, 2004 1:15 PM
>  >Subject: TSIO520
>  >
>  >
>  >> Do you have a prop that would work on a TSIO520, in a pusher
>  >configuration.
>  >>
>  >> thanks,
>  >>
>  >> Scott
>  >>
>
> "Those who sacrifice freedom to get security, deserve neither."
> - Benjamin Franklin
>
> _______________________________________________
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