Re: REFLECTOR: Props

["Milton Mersky" <miltonm@onramp.net>]

-----Original Message-----
From: Simon Aegerter <aegerter@dataway.ch>
To: reflector@awpi.com <reflector@awpi.com>; NMFlyer1@aol.com
<NMFlyer1@aol.com>
Date: Thursday, May 20, 1999 2:07 PM
Subject: Re: REFLECTOR: Props


>>I'm curious about props also.
>
>Here's another input: mine is a 66" MT on a Franklin 210 HP 6cyl. Pitch is
>from 41" to 100". The airframe is an Elite LW (formerly 173)
>
>>I talked to IVO while at Sun-N-Fun and
>>told him about my Chevy V-6 installation. Specifically, I asked him
whether
>>his Magnum blades would have enough bite for my (over) 300 HP V-6.
>
>Please, Kurt, do yourself a favour and forget the IVO. No matter how much
>bite the blades may have, unless it has been thouroughly re-engineered by a
>professional since I have last seen it anout a year ago, it is far from
>adequate to handle 300 hp. After inspection, I have declined to use it on
>my 210 hp.
>
>>His input
>>was to just put the biggest prop I could on there, perhaps a 72" ?
>
>Unless your reduction gear puts the prop way above the crankshaft line you
>should not be able to accomodate 72". You need at least 5, preferentially
>6" of ground clearance. Otherwise you risk to scratch the runway when you
>land with a slightly bigger angle of attack than usual. We had a guy in a
>neighboring hangar with a Cosy that had about 2.5" of clearance. He ruined
>two props (MTs!) before he learned to land it with a touch down speed of
>not under 100 kt!
>
>> I would love to use an MT prop, but find it really hard to live with the
>>cost.
>
>Well, some people have found it hard to die with a bargain. Seriously: if
>you consider the total cost of the project the incremental cost of going to
>the MT really isn't that big. What's perhaps even more compelling: since
>you have gone to the trouble to fit a 300 hp engine, you should really go
>all the way. You NEED a constant speed prop. That leaves you with a choice:
>buy an MT or steel an MT. Everything else is like buying a gallon of wine
>and carry it home in a 1 qt bottle IMHO.
>
>Sorry, if that's an expensive e-mail. <g>
>All the best
>Simon
>
>Simon Aegerter, Winterthur, Switzerland


I urge you not to consider an IVO prop.  I think IVO has a long way to go
before being able to power any engine, let alone 300 HP. Constant speed is
not only nice to have but it is a necessity for performance at either edge
of the performance envelope.

Milton Mersky
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