Today's Message Index:
----------------------
1. 03:07 AM - A2200 rpm's (ces308)
2. 03:36 AM - Re: A2200 rpm's (Richard Girard)
3. 06:44 AM - Re: A2200 rpm's (Naftali Horowitz)
4. 07:29 AM - Re: A2200 rpm's (dons701)
5. 10:04 AM - Re: A2200 rpm's (Richard Girard)
Message 1
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Hello all...
I was running a Sensenich 58-44 prop that was giving me 31-3300 on take off and
worked just fine .I put an Arrowprop 58-44 on and can only get 2650 on take off.I
have a new Sensenich coming...my question is,am I hurting the engine at all
running the Arrowprop at the lower rpm until I get my other prop??
Thanks,
chris ambrose
M3X Kolb / Jabiru A-2200 ser # 1228 141.8 hrs
N327CS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=308335#308335
Message 2
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The answer is possibly. It's like trying to start your car rolling in third
gear instead of first. The main thing you are losing is horsepower. Excess
horsepower is what makes climbing possible.
You might ask how two propellers rated as having the same pitch can have
such wildly differing performance on your aircraft. The answer is that there
is no specification about where or how that measurement is taken. One prop
make might measure the pitch at the 75% of diameter point and use the bottom
of the prop as the reference surface. Another might use the prop tip and the
chord of the propeller airfoil.
I have used this example on the Kolb forum so you might have seen it there.
Bear with me.
Several years ago, before I made the decision to go LSA, I was building a
LongEZ. I was offered a propeller made by a known maker that was reputed to
be optimized for the engine I intended to use. It had been done by Don
Bates, author of the prop optimizer program, himself. I eventually sold the
prop to a Varieze owner with the correct engine for it. He bought the prop
on condition that he be able to mount and try it first, and we agreed. While
he wasn't that impressed with the prop, it was at least as good as what he
was running so he bought it as a spare. A few months later he contacted the
props maker about having it reworked for a little more performance. Said
prop maker was the new owner of the brand and not the original carver who
had created it. When my buddy got the prop back he could tell that the
blades were a little thinner, but the new carver claimed it was still the
same pitch as before. I got a call the evening after he mounted and flew the
newly modified propeller. His Varieze, with no other modifications, just
putting on the propeller, was 40 MPH faster.
My point is that those numbers, 58 X 44 are relative, only testing and
investigation will tell you what they are relative to.
Rick Girard
On Wed, Aug 11, 2010 at 5:06 AM, ces308 <ces308@ldaco.com> wrote:
>
> Hello all...
>
> I was running a Sensenich 58-44 prop that was giving me 31-3300 on take off
> and worked just fine .I put an Arrowprop 58-44 on and can only get 2650 on
> take off.I have a new Sensenich coming...my question is,am I hurting the
> engine at all running the Arrowprop at the lower rpm until I get my other
> prop??
>
> Thanks,
>
> chris ambrose
> M3X Kolb / Jabiru A-2200 ser # 1228 141.8 hrs
> N327CS
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=308335#308335
>
>
Message 3
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Wxtra 40 mph seems exaggerated
Subject: Re: JabiruEngine-List: A2200 rpm's
From: aslsa.rng@gmail.com
The answer is possibly. It's like trying to start your car rolling in third
gear instead of first. The main thing you are losing is horsepower. Excess
horsepower is what makes climbing possible.
You might ask how two propellers rated as having the same pitch can have su
ch wildly differing performance on your aircraft. The answer is that there
is no specification about where or how that measurement is taken. One prop
make might measure the pitch at the 75% of diameter point and use the botto
m of the prop as the reference surface. Another might use the prop tip and
the chord of the propeller airfoil.
I have used this example on the Kolb forum so you might have seen it there.
Bear with me.
Several years ago=2C before I made the decision to go LSA=2C I was building
a LongEZ. I was offered a propeller made by a known maker that was reputed
to be optimized for the engine I intended to use. It had been done by Don
Bates=2C author of the prop optimizer program=2C himself. I eventually sold
the prop to a Varieze owner with the correct engine for it. He bought the
prop on condition that he be able to mount and try it first=2C and we agree
d. While he wasn't that impressed with the prop=2C it was at least as good
as what he was running so he bought it as a spare. A few months later he co
ntacted the props maker about having it reworked for a little more performa
nce. Said prop maker was the new owner of the brand and not the original ca
rver who had created it. When my buddy got the prop back he could tell that
the blades were a little thinner=2C but the new carver claimed it was stil
l the same pitch as before. I got a call the evening after he mounted and f
lew the newly modified propeller. His Varieze=2C with no other modification
s=2C just putting on the propeller=2C was 40 MPH faster.
My point is that those numbers=2C 58 X 44 are relative=2C only testing and
investigation will tell you what they are relative to.
Rick Girard
On Wed=2C Aug 11=2C 2010 at 5:06 AM=2C ces308 <ces308@ldaco.com> wrote:
Hello all...
I was running a Sensenich 58-44 prop that was giving me 31-3300 on take off
and worked just fine .I put an Arrowprop 58-44 on and can only get 2650 on
take off.I have a new Sensenich coming...my question is=2Cam I hurting the
engine at all running the Arrowprop at the lower rpm until I get my other
prop??
Thanks=2C
chris ambrose
M3X Kolb / Jabiru A-2200 ser # 1228 141.8 hrs
N327CS
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=308335#308335
-List" target="_blank">http://www.matronics.com/Navigator?JabiruEngine-Li
st
http://forums.matronics.com
le=2C List Admin.
="_blank">http://www.matronics.com/contribution
Message 4
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Hi Chris
Another consideration is the fuel rate at the new RPM. It would be interesting
to see your full throttle EGT's with the two different props. I may be wrong,
but I believe you could be running leaner at full throttle with the lower RPM
prop.
Don
--------
Zenith 701 #76120
Jabiru 2200A #2456 67 hours
Sensenich Wood 64-PJ-36 Prop
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=308362#308362
Message 5
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The pilot in question was ex military and life long pilot. I've known him
for almost 10 years and I do not doubt his report, he is a pretty careful
guy. You're free to feel as you wish, though, that's democracy.
Rick
On Wed, Aug 11, 2010 at 8:43 AM, Naftali Horowitz <naftalih@hotmail.com>wrote:
> Wxtra 40 mph seems exaggerated
>
> ------------------------------
> Date: Wed, 11 Aug 2010 05:36:13 -0500
> Subject: Re: JabiruEngine-List: A2200 rpm's
>
> From: aslsa.rng@gmail.com
> To: jabiruengine-list@matronics.com
>
>
> The answer is possibly. It's like trying to start your car rolling in third
> gear instead of first. The main thing you are losing is horsepower. Excess
> horsepower is what makes climbing possible.
> You might ask how two propellers rated as having the same pitch can have
> such wildly differing performance on your aircraft. The answer is that there
> is no specification about where or how that measurement is taken. One prop
> make might measure the pitch at the 75% of diameter point and use the bottom
> of the prop as the reference surface. Another might use the prop tip and the
> chord of the propeller airfoil.
> I have used this example on the Kolb forum so you might have seen it there.
> Bear with me.
> Several years ago, before I made the decision to go LSA, I was building a
> LongEZ. I was offered a propeller made by a known maker that was reputed to
> be optimized for the engine I intended to use. It had been done by Don
> Bates, author of the prop optimizer program, himself. I eventually sold the
> prop to a Varieze owner with the correct engine for it. He bought the prop
> on condition that he be able to mount and try it first, and we agreed. While
> he wasn't that impressed with the prop, it was at least as good as what he
> was running so he bought it as a spare. A few months later he contacted the
> props maker about having it reworked for a little more performance. Said
> prop maker was the new owner of the brand and not the original carver who
> had created it. When my buddy got the prop back he could tell that the
> blades were a little thinner, but the new carver claimed it was still the
> same pitch as before. I got a call the evening after he mounted and flew the
> newly modified propeller. His Varieze, with no other modifications, just
> putting on the propeller, was 40 MPH faster.
> My point is that those numbers, 58 X 44 are relative, only testing and
> investigation will tell you what they are relative to.
>
> Rick Girard
>
> On Wed, Aug 11, 2010 at 5:06 AM, ces308 <ces308@ldaco.com> wrote:
>
>
> Hello all...
>
> I was running a Sensenich 58-44 prop that was giving me 31-3300 on take off
> and worked just fine .I put an Arrowprop 58-44 on and can only get 2650 on
> take off.I have a new Sensenich coming...my question is,am I hurting the
> engine at all running the Arrowprop at the lower rpm until I get my other
> prop??
>
> Thanks,
>
> chris ambrose
> M3X Kolb / Jabiru A-2200 ser # 1228 141.8 hrs
> N327CS
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=308335#308335
>
>
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> -List" target="_blank">
> http://www.matronics.com/Navigator?JabiruEngine-List
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> ="_blank">http://www.matronics.com/contribution
> ==========
>
>
> *
>
> -List" target=_blank>http://www.matronics.com/Navigator?JabiruEngine-List
> ttp://forums.matronics.com
> =_blank>http://www.matronics.com/contribution
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