Today's Message Index:
----------------------
1. 05:39 AM - Re: High Thrust Line Question (George Alexander)
2. 05:47 AM - Re: Kolb-List Digest: 15 Msgs - 05/07/18 (Dennis Souder)
3. 06:09 AM - Re: High Thrust Line Question (Richard Girard)
4. 06:19 AM - Re: High Thrust Line Question (Richard Girard)
5. 04:39 PM - Re: High Thrust Line Question (Richard Pike)
6. 08:09 PM - Re: Re: High Thrust Line Question (Bill Berle)
7. 08:22 PM - Re: Re: High Thrust Line Question (John Hauck)
Message 1
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| Subject: | Re: High Thrust Line Question |
victorbravo(at)sbcglobal. wrote:
> S- N- I- P
>
> With the 3.47 gearbox I have, a three blade propeller with 62-64 inch diameter
is not enough... the engine will overspeed before I get the full amount of thrust.
>
> S- N- I- P
>
>
> Bill Berle
> S- N- I- P
>
MY FS II is equipped with R503 DCDI, a C Box 3.47 - 1, mounted in the "Up" position
and swinging a 68", 3 blade Powerfin 'F' model prop.
In a couple of hundred hours, have encountered none of the problems you identified
as potential ones.
--------
George Alexander
FS II R503
E-LSA N709FS
http://www.oh2fly.net
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=479931#479931
Attachments:
http://forums.matronics.com//files/fsii_031sm_973.jpg
Message 2
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| Subject: | RE: Kolb-List Digest: 15 Msgs - 05/07/18 |
You could keep the down box and raise the engine to whatever height might be
needed.
I think flipping the box would put the prop higher than needed - forget how
much.
You can get a wider chord prop to Absorb more power in a smaller dia. The
prop mfg could say what would work with the 3.47 box.
Just some thought based on fuzzy recollections.
Dennis
________________________________ Message 6
_____________________________________
Time: 03:23:13 PM PST US
From: Bill Berle <victorbravo@sbcglobal.net>
Subject: Kolb-List: High Thrust Line Question
Kolbers, I ran into a significant problem on my Firestar, and it may cause
me to not be able to finish the project. I hope this is not as much of a
problem as I fear.
When I bought my HKS engine I did not know to ask whether it had one type
gearbox or another. It has the 3.47 to 1 box, which will spin a large
propeller very slowly.
After reading some ot the Kolb List stories about high thrust lines and
putting the Kolb over on its nose, I realized I wanted to keep the thrust
line as low as possible for best performance and handling. However, with the
gearbox rotated to the "down" position, it limited the propeller diameter to
64 inches with a one inch tailboom clearance. With the 3.47 gearbox I have,
a three blade propeller with 62-64 inch diameter is not enough... the engine
will overspeed before I get the full amount of thrust.
Someone suggested using a four or five blade propeller, but that would
prevent the wings from folding back.
I contacted the engine distributor to ask if I could switch the gears around
to make my gearbox a 2.58 to 1 ratio,a nd you cannot do that without
changing the gearbox itself.
So I asked how much it would cost to buy a new gearbox, andit is way too
high for me to consider doing right now. Maybe when I win the lottery.
Someone else suggested that I turn the gearbox around facing "up", which
would allow a much larger propeller. My first reaction was "Oh goodness no,
that will raise the thrust line too high, and it will cause the airplane to
nose over on takeoff, I'll run out of elevator control, etc. etc...."
But then I realized that was an assumption rather than a known fact. Before
I gave up on the project, perhaps I can move the gearbox upwards and not
have problems...
but how far?
So I would like to ask the experienced Kolbers: JUST EXACTLY HOW HIGH can
the thrust line be on a Kolb Firestar 2 before it creates
safety/handling/nose-over problems? Can the center of the propeller be 34
inches above the tailboom...36
inches...38 inches...40 inches????
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit
entities
Message 3
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| Subject: | Re: High Thrust Line Question |
Don't bother wasting your time calling Darryl. He'll tell you that the
gearbox won't work, blah, blah, blah. Horse exhaust. He told me that the 4
to 1 gearbox I run with a 582 was all wrong. Funny thing though, when I had
a 582 in the shop with a 2.57 gearbox I started swapping props between the
two. I had to put about 20 minutes (yeah, 1/3 of a degree) more pitch on
the 4 to 1 engine. Otherwise, performance was the same. For what it's
worth, the R3350's of the B29 turned the prop at a bit over 900 rpm.
Suggest you leave the gearbox in the up position and put the short side up
on the front engine mount and put the rear mounts long side up.
Don't know if it will transfer from the Mk III but the lower prop rpm
allows me to run a rudder trim tab that's about 1/3 the size of the factory
recommended tab and the total deflection angle is only about 5 degrees. I
need a tiny amount of right rudder on takeoff and a bit of left rudder in
cruise.
As for running a four or five blade prop, I have run a three blade Warp and
a four blade Power Fin on my HKS. No difference when set right. I even
stripped the Power Fin back to two blades. It vibrated a bit more and made
virtually no difference so I put the other two blades back in.
If you think your thrust line is high, look at the pics. Travis told me the
factory set this engine up for the fourth owner of the PFH (plane from
hell) who just had to have an "E" gearbox.
Your HKS will power your Firestar just fine, your prop will work just fine.
I set my HKS so that the prop tops out at 6000 rpm on climb out.
Rick
On Mon, May 7, 2018 at 9:46 PM, Bill Berle <victorbravo@sbcglobal.net>
wrote:
>
> With the propeller shaft in the SAME "down" position, the 3.47 gearbox I
> have will make the propeller turn at 1671 RPM at theax. coninuous power o
f
> 5800 engine RPM. At "cruise" RPM it will turn even slower. With the 2.58
> gearbox that I suspect you have, your propeller will turn almost 2250 at
> 5800 engine RPM.
>
> So with those numbers, in order to get the same thrust (and absorb the
> same 60 horsepower and torque from the HKS) I would need a whole lot more
> propeller blade area than you would need. Usually you can just put on a 4
> blade prop or 5 blade, and that will do the trick. But with a Kolb you
> can't do it and still fold the wings.
>
> Putting on a much wider chord propeller blade (a paddle prop that looks
> like a T-28 warbird) could work, but again in this case the prop blades
> would hit the rear of the wing when folded.
>
> HKS says the gearbox will take almost $2000 to buy, plus some special
> tools they would rent me, and however much time from a qualified mechanic
> familiar with these engines. Plus the use of a hydraulic shop press. That
> is not gonna work in my current situation, and so I briefly considered
> selling everything I had, engine, airframe, etc. and starting over with
> another option. But now I have myself calmed down a little and am not
> throwing wrenches across the shop cursing :)
>
> So before I do anything rash, I want to figure out whether the "up"
> position of the gearbox is a minor problem or a huge problem. I know that
> "down" is the preference, but that cannot happen because I have the wrong
> gearbox.
>
> I will be HAPPY to call Warp Drive and ask them, he may have some magic
> wand that the other prop manufacturers don't have.
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
>
> --------------------------------------------
> On Mon, 5/7/18, Larry Cottrell <lcottrell1020@gmail.com> wrote:
>
> Subject: Re: Kolb-List: High Thrust Line Question
> To: "kolb-list@matronics.com" <kolb-list@matronics.com>
> Date: Monday, May 7, 2018, 5:45 PM
>
> I don't know for
> sure what gear box, but whatever, the location of the
> propeller shaft shouldn't change. Why don't you call
> Daryl at Warp and tell him what you have and what he
> recommends. John turned me on to him and he hasn't done
> me or anyone that I know of,
> wrong.Larry
> On Mon, May 7, 2018 at
> 5:02 PM, Bill Berle <victorbravo@sbcglobal.net>
> wrote:
> Bill Berle <victorbravo@sbcglobal.net>
>
>
> On Mon, 5/7/18, Larry Cottrell <lcottrell1020@gmail.com>
> wrote:
>
>
> I'm swinging a 66 inch Warp with the gear box in
> the down position.
>
>
> With the 3.47 to 1 gearbox????
>
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Message 4
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| Subject: | Re: High Thrust Line Question |
PS, the other benefit of lower prop rpm is that your airplane will be a
whole lot more quiet. My neighbors told me they could hear the 2.57 gearbox
engine all the way around the pattern, but the 4.00 gearbox was below
hearing level when the plane was on downwind.
Rick
On Tue, May 8, 2018 at 8:08 AM, Richard Girard <aslsa.rng@gmail.com> wrote:
> Don't bother wasting your time calling Darryl. He'll tell you that the
> gearbox won't work, blah, blah, blah. Horse exhaust. He told me that the
4
> to 1 gearbox I run with a 582 was all wrong. Funny thing though, when I h
ad
> a 582 in the shop with a 2.57 gearbox I started swapping props between th
e
> two. I had to put about 20 minutes (yeah, 1/3 of a degree) more pitch on
> the 4 to 1 engine. Otherwise, performance was the same. For what it's
> worth, the R3350's of the B29 turned the prop at a bit over 900 rpm.
> Suggest you leave the gearbox in the up position and put the short side u
p
> on the front engine mount and put the rear mounts long side up.
> Don't know if it will transfer from the Mk III but the lower prop rpm
> allows me to run a rudder trim tab that's about 1/3 the size of the facto
ry
> recommended tab and the total deflection angle is only about 5 degrees. I
> need a tiny amount of right rudder on takeoff and a bit of left rudder in
> cruise.
> As for running a four or five blade prop, I have run a three blade Warp
> and a four blade Power Fin on my HKS. No difference when set right. I eve
n
> stripped the Power Fin back to two blades. It vibrated a bit more and mad
e
> virtually no difference so I put the other two blades back in.
> If you think your thrust line is high, look at the pics. Travis told me
> the factory set this engine up for the fourth owner of the PFH (plane fro
m
> hell) who just had to have an "E" gearbox.
> Your HKS will power your Firestar just fine, your prop will work just fin
e.
> I set my HKS so that the prop tops out at 6000 rpm on climb out.
>
> Rick
>
> On Mon, May 7, 2018 at 9:46 PM, Bill Berle <victorbravo@sbcglobal.net>
> wrote:
>
>>
>> With the propeller shaft in the SAME "down" position, the 3.47 gearbox I
>> have will make the propeller turn at 1671 RPM at theax. coninuous power
of
>> 5800 engine RPM. At "cruise" RPM it will turn even slower. With the 2.58
>> gearbox that I suspect you have, your propeller will turn almost 2250 at
>> 5800 engine RPM.
>>
>> So with those numbers, in order to get the same thrust (and absorb the
>> same 60 horsepower and torque from the HKS) I would need a whole lot mor
e
>> propeller blade area than you would need. Usually you can just put on a
4
>> blade prop or 5 blade, and that will do the trick. But with a Kolb you
>> can't do it and still fold the wings.
>>
>> Putting on a much wider chord propeller blade (a paddle prop that looks
>> like a T-28 warbird) could work, but again in this case the prop blades
>> would hit the rear of the wing when folded.
>>
>> HKS says the gearbox will take almost $2000 to buy, plus some special
>> tools they would rent me, and however much time from a qualified mechani
c
>> familiar with these engines. Plus the use of a hydraulic shop press. Tha
t
>> is not gonna work in my current situation, and so I briefly considered
>> selling everything I had, engine, airframe, etc. and starting over with
>> another option. But now I have myself calmed down a little and am not
>> throwing wrenches across the shop cursing :)
>>
>> So before I do anything rash, I want to figure out whether the "up"
>> position of the gearbox is a minor problem or a huge problem. I know tha
t
>> "down" is the preference, but that cannot happen because I have the wron
g
>> gearbox.
>>
>> I will be HAPPY to call Warp Drive and ask them, he may have some magic
>> wand that the other prop manufacturers don't have.
>>
>> Bill Berle
>> www.ezflaphandle.com - safety & performance upgrade for light aircraft
>> www.grantstar.net - winning proposals for non-profit and
>> for-profit entities
>>
>> --------------------------------------------
>> On Mon, 5/7/18, Larry Cottrell <lcottrell1020@gmail.com> wrote:
>>
>> Subject: Re: Kolb-List: High Thrust Line Question
>> To: "kolb-list@matronics.com" <kolb-list@matronics.com>
>> Date: Monday, May 7, 2018, 5:45 PM
>>
>> I don't know for
>> sure what gear box, but whatever, the location of the
>> propeller shaft shouldn't change. Why don't you call
>> Daryl at Warp and tell him what you have and what he
>> recommends. John turned me on to him and he hasn't done
>> me or anyone that I know of,
>> wrong.Larry
>> On Mon, May 7, 2018 at
>> 5:02 PM, Bill Berle <victorbravo@sbcglobal.net>
>> wrote:
>> Bill Berle <victorbravo@sbcglobal.net>
>>
>>
>>
>> On Mon, 5/7/18, Larry Cottrell <lcottrell1020@gmail.com>
>> wrote:
>>
>>
>>
>> I'm swinging a 66 inch Warp with the gear box in
>> the down position.
>>
>>
>>
>> With the 3.47 to 1 gearbox????
>>
>> ==== ===================
=========== =
>>
>> -List" rel="noreferrer"
>> target="_blank">http://www.matronics.com/
>> Navigator?Kolb-List
>>
>> ==== ===================
=========== =
>>
>> FORUMS -
>>
>> eferrer"
>> target="_blank">http://forums.matronics.com
>>
>> ==== ===================
=========== =
>>
>> WIKI -
>>
>> errer"
>> target="_blank">http://wiki.matronics.com
>>
>> ==== ===================
=========== =
>>
>> b Site -
>>
>> -Matt Dralle, List Admin.
>>
>> rel="noreferrer"
>> target="_blank">http://www.matronics.com/
>> contribution
>>
>> ==== ===================
=========== =
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>> --
>> The
>> older I get, the less tolerant I am of those who are
>> intolerant of others.
>> If you forward this email, or any part of
>> it, please remove my email address before sending.
>>
>>
>>
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===========
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===========
>>
>>
>>
>>
>
>
> --
> =9CBlessed are the cracked, for they shall let in the light.
=9D Groucho Marx
> <http://www.goodreads.com/author/show/43244.Groucho_Marx>
>
>
--
=9CBlessed are the cracked, for they shall let in the light.=9D
Groucho Marx
<http://www.goodreads.com/author/show/43244.Groucho_Marx>
Message 5
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| Subject: | Re: High Thrust Line Question |
Bill; notice the extent to which Rick raised his engine. (Great pictures) Maybe
you can leave the gearbox down and raise the engine up?
--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=479963#479963
Message 6
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| Subject: | Re: High Thrust Line Question |
Everybody THANK YOU for taking time for this discussion.
I spoke to the Kolb factory today by phone, and went out to the local UL flying
field to see an HKS engine run.
Duane and Bryan at Kolb were asked one specific question by me: What is the maximum
number of inches allowable or advisable between the center of the propeller
and the top of the tailboom?
Bryan said that 36 inches is about standard for a "normal" Firestar, and he would
not want to fly an airplane with that distance raised to 39 or 40 inches.
I went back to my hangar and measured, and the distance on my Firestar would be
over 40 or 41 inches if I turned the gearbox upward. So if the Kolb factory owner
says 40 inches is too high, I can only be humble and assume that I wouldn't
want to fly it at 40 inches either. If any of the highly experienced Kolbers
on this forum are flying with their thrust line 40 inches above the tailboom,
I REALLY would like to know about it pronto.
As big of an ego as I have had a few times in my life, and as much as I think of
myself as a reasonably skilled pilot, I don't need to be a test pilot here
and try to push any envelope at this early stage. So if I can ask the Kolb ilst
a favor... if any of you are flying a Firestar with the engine thrust line 39
or 40 or 41 incvhes above the tailboom please post this on the list and let
me know ifyou have any issues with the handling, pitch-over, etc.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Tue, 5/8/18, Richard Pike <thegreybaron@charter.net> wrote:
Subject: Kolb-List: Re: High Thrust Line Question
To: kolb-list@matronics.com
Date: Tuesday, May 8, 2018, 4:38 PM
Pike" <thegreybaron@charter.net>
Bill; notice the extent to which Rick
raised his engine. (Great pictures) Maybe you can leave the
gearbox down and raise the engine up?
--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
Forgiving is tough, being forgiven is
wonderful, and God's grace really is amazing.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=479963#479963
The Kolb-List Email Forum -
Navigator to browse
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Message 7
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| Subject: | Re: High Thrust Line Question |
I am certainly not an aeronautical engineer by any means, but I realize that the
higher the thrust line the more power it takes to fly. That long arm/lever
is doing a good job of pushing the nose down, the elevators are working hard to
keep the nose up, and that all takes power. Eventually the high thrust line
would probably consume the aircraft.
I mentioned a day or so ago a major difference from flying my mkIII with an 80
hp and then making my first takeoff with the 100 hp. It wouldn't break ground
until I came back on the power. In a short time muscle memory took care of that
little problem, but it was a good demonstration to me how much a high thrust
line consumes power.
Some things work and some don't.
john h
mkIII
Titus, Alabama
-----Original Message-----
From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Bill Berle
Sent: Tuesday, May 08, 2018 10:08 PM
Subject: Re: Kolb-List: Re: High Thrust Line Question
Everybody THANK YOU for taking time for this discussion.
I spoke to the Kolb factory today by phone, and went out to the local UL flying
field to see an HKS engine run.
Duane and Bryan at Kolb were asked one specific question by me: What is the maximum
number of inches allowable or advisable between the center of the propeller
and the top of the tailboom?
Bryan said that 36 inches is about standard for a "normal" Firestar, and he would
not want to fly an airplane with that distance raised to 39 or 40 inches.
I went back to my hangar and measured, and the distance on my Firestar would be
over 40 or 41 inches if I turned the gearbox upward. So if the Kolb factory owner
says 40 inches is too high, I can only be humble and assume that I wouldn't
want to fly it at 40 inches either. If any of the highly experienced Kolbers
on this forum are flying with their thrust line 40 inches above the tailboom,
I REALLY would like to know about it pronto.
As big of an ego as I have had a few times in my life, and as much as I think of
myself as a reasonably skilled pilot, I don't need to be a test pilot here
and try to push any envelope at this early stage. So if I can ask the Kolb ilst
a favor... if any of you are flying a Firestar with the engine thrust line 39
or 40 or 41 incvhes above the tailboom please post this on the list and let
me know ifyou have any issues with the handling, pitch-over, etc.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Tue, 5/8/18, Richard Pike <thegreybaron@charter.net> wrote:
Subject: Kolb-List: Re: High Thrust Line Question
To: kolb-list@matronics.com
Date: Tuesday, May 8, 2018, 4:38 PM
Pike" <thegreybaron@charter.net>
Bill; notice the extent to which Rick
raised his engine. (Great pictures) Maybe you can leave the
gearbox down and raise the engine up?
--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
Forgiving is tough, being forgiven is
wonderful, and God's grace really is amazing.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=479963#479963
The Kolb-List Email Forum -
Navigator to browse
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7-Day Browse, Chat, FAQ,
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