Having said my bit several times before I hesitate to
repeat it, but here is a short version: firstly I have a
lot of friends using the Airmaster and they are happy with
it, and it is clear to me hat it s a good propeller. I
first became interested in the Woodcomp/Kremen as it then
was, when I saw Tom Justic with a 914/Woodcomp combination
appear to significantly out climb the Europa Company
914/Airmaster during the 2000 Europa Club fly out to
Prague
I ended up buying a Woodcomp SR2000. This performed
well, but not I suspect any better than an Airmaster, and
indeed the blade characteristics wre fairly similar. There
were issues with the power of the pitch change motor
affecting the system reliability which I feel have been
largely addressed in the later SR3000 range. I changed to
an SR3000W prop when I was trying to optimise performance
with a view to flying to Australia. This has a blade twist
of around 26 degrees (compared with something of the order
of 12 degrees for the SR2000 and the Warp Drive blades),
which is what you need theoretically to fly at speeds in
the 90 to 160kt range -we were hoping to go to Australia
at 150kts cruising at 10,000ft. I did closely monitored
comparisons between my planes performance with he two
propellers. With the SR3000 the climb rate and fuel
consumption were slightly better. Top speed at various
heights was 4kts higher (equivalent to an extra 7 HP) but
most striking of all was that my cooling (which had always
been a problem) was totally transformed. I no longer
boiled if held up at the Rally waiting behind several
planes for take off, and for the first time I could do a
5min full power climb.
So my message to anyone having persiistent
problems with 914/XS cooling is to get hold of a high
twist propeller. The explanation, which barely needs
stating is that with a low twist propeller the central
part of the prop is effectively in Beta mode at any speed
over 40kts and is diverting air away from the cooling
intakes.
Regards, David Joyce, G-XSDJ
Ken Carpenter <kbcarpenter@comcast.net> wrote:
> Will add my two bits to the discussion. Have been using
>Airmaster prop with three blade warp drive for 550 hours.
> No sig problems and was able to replace one blade
>without difficulty when one blade damaged. Had a wire in
>the hub break while flying and it no sig problem. Just
>stayed at the climb rpm till got back on ground.
> Have been happy with it...though have never flown with
>any other prop.
> Ken carpenter
> N212KC. 914 mono
>
> Sent from my iPad
>
> On Jun 13, 2013, at 3:43 PM, "Bud Yerly"
><budyerly@msn.com> wrote:
>
>> Remi,
>> I am distressed that you are still having cooling
>>issues. If you did all I described in the cooling 101
>>article printed in the Europa Flyer, it should cool
>>handily.
>>
>> I can operate for 25 minutes on the ground and not hit
>>275F on a 90F day. The XS cowl is not optimal, but the
>>root width is the same with my 332 as yours.
>> The mono exit from your engine compartment is probably
>>only an inch wide, but if your ducting is sealed you
>>should be able to cool very well in Europe.
>>
>> I gave Martin my ideas for a root extension for the
>>ferrule on the WD blade, as I just don't have time to
>>make one up. It basically is an extension to the blade
>>and a riveted airfoil shape to the spinner similar to the
>>new blades on the C130J and other turboprop engine/prop
>>combinations. That will help a breeze close in to the
>>cowl, but is intended for cruise performance increase.
>>
>> Check your ducting carefully. If you did not see my
>>changes for the XS cowl, refer to my website or
>>Airmaster's website (Europa Application) for download.
>>
>> Bud Yerly
>> www.customflightcreations.com
>> ----- Original Message -----
>> From: Guerner Remi
>> To: Europa-List Digest Server
>> Sent: Tuesday, June 11, 2013 4:11 AM
>> Subject: Europa-List: Re: Woodcomp or Airmaster Prop
>>
>><air.guerner@orange.fr>
>>
>> <<<<The "extra" twist for enhancement of cowl port
>>airflow is not a
>> factor in a 912s application.>>>>>
>>
>> Hi Ira,
>> I have 630 hours on my Airmaster AP332/WarpDrive and I
>>am very happy with the reliability and performance of
>>this prop. But the cooling problem on the ground with the
>>WarpDrive blades is a big inconvenience, with any engine.
>>All Europas I know, fitted with the WarpDrive prop, fixed
>>or variable pitch, even with the 80 HP 912 have this
>>ground cooling problem as soon as they have to wait more
>>than a few minutes at the holding point in hot weather.
>>With the existing Europa XS cowl, I believe the only
>> solution would be to have wider blades at the root and
>>higher twist, as offered by Woodcomp.
>> Regards
>> Remi Guerner
>> F-PGKL, XS Monowheel, 912ULS, 1014 hours.
>> p; Features Chat, http://www.matronnbsp; via
>>the Web title=http://forums.matronics.com/
>>href="http://forums.matronics.com";>http://forums.matronics.com
>> _p; generous bsp;
>> title=http://www.matronics.com/contribution
>>href="http://www.matronics.com/contribution";>http://www.matronics.com/c================
>>
>>
>>
>>
>>
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