Yes, but your Subaru engine has such a large surfeit of power that it can
get away with such high amounts of twist whilst retaining acceptable levels
of climb (due to the excess of power). Try that on a 912 and it may all end
in tears!
Duncan McF.
----- Original Message -----
From: "GLENN CROWDER" <gcrowder2@hotmail.com>
Subject: Re: Europa-List: Propellers
>
> I gained a solid 20 mph by dumping my NSI CAP140 3 bladed electrically
> adjustable prop
> with the Warp Drive blades for a custom designed fixed pitch 3 blade on my
> 125 hp EA81 powered mono.
> Whenever I flew with the NSI, I would be constantly fiddling with with
> the
> pitch control.
> It was just adding too much workload to be fun. I really like the fixed
> pitch. It is far
> smoother than the NSI and since it is custom fitted to my engine climbs
> just
> as well.
> The WD blades were designed for a 100 mph max ultralight and have only an
> 18 degree
> twist on a 74" blade. All WD blades are cut down to length from the same
> 74" blanks. When you cut them down to 64" they have even less twist. A
> proper twist for a 150 mph plane is between 40 and 45 degrees. The WD
> blades are a good climb type blade but were never designed for higher
> speeds.
> I do have a slightly longer takeoff roll as I need some speed for the
> prop
> to start to bite but
> I fly off a 4700 ft runway so is not an issue for me.
>
> Glenn
> Golden, Colorado
> USA
>
>
>>From: grroberts3@juno.com
>>Reply-To: europa-list@matronics.com
>>To: europa-list@matronics.com
>>Subject: Re: Europa-List: Propellers
>>Date: Mon, 21 Nov 2005 19:39:56 -0700
>>
>>
>>"The Aviation Consumer" magazine did an article on just that topic in
>>August 2005. Bottom line: for aircraft under 250 HP, gains in
>>performance were subjective and variable. In general, three blades gave
>>better climb, less noise, less vibration, more ground clearance, and
>>looked sexy. Two blades produced higher cruise speed on less fuel , were
>>lighter, and were cheaper: but not always.
>>
>>I don't care to defend these conclusions, I'm merely summarizing the
>>article.
>>
>>GRoberts
>>A187
>>
>>
>>writes:
>> >
>> >
>> > Propeller Experts !!
>> >
>> > I wish to upgrade to a CS prop with full feather option, the main
>> > reason
>> > being the feathering capability. The obvious choice for many is the
>> >
>> > Airmaster AP332. Now the Woodcomp SR3000 has the same options, and I
>> > believe
>> > is a lot cheaper. In addition it has the option for a 2 or 3-bladed
>> >
>> > propeller. My question is this :
>> > What are the pros and cons between 2 and 3 blades, apart from the
>> > considerable weight saving of 4 kg. Why are we all using 3-bladed
>> > Warp
>> > Drives ? The Katana, which is a similar but much heavier aircraft
>> > uses a
>> > 2-bladed CS Hoffmann on a Rotax 912.
>> >
>> > Any ideas ?
>> >
>> > Karl
>> >
>> >
>> > =======================================
>> >
>> >
>> >
>> >
>> >
>> >
>>
>>
>
>
>
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