Today's Message Index:
----------------------
1. 01:23 AM - Re: Firestar/HKS Engine Test Run (Bill Berle)
2. 06:01 AM - Re: Firestar/HKS Engine Test Run (Gary Aman)
3. 06:22 AM - Re: Firestar/HKS Engine Test Run (Charlie England)
4. 08:40 AM - Re: Firestar/HKS Engine Test Run (John Hauck)
5. 08:44 AM - Re: Firestar/HKS Engine Test Run (John Hauck)
6. 08:44 AM - Re: Firestar/HKS Engine Test Run (John Hauck)
7. 10:02 AM - Re: Firestar/HKS Engine Test Run (Charlie England)
Message 1
INDEX | Back to Main INDEX |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Firestar/HKS Engine Test Run |
Thank you guys again for putting your brains on this :)
A year ago I had contacted Jerry Olenik at Green Sky (RIP Jerry), and he gave
me a rough number of "something about 24 inches" between the exhaust flange and
the merge. That is what we built. I had actually sent HKS Japan an e-mail and
got no reply whatsoever (not even a rejection to my request for info). That
was disappointing, and not 100% professional on their part.
The exhaust has a "restraining collar" bolted to the bolt that holds the tailboom
tube to the fuselage at the back of the cage. This restraint is like a giant
Adel clamp, except it has 1/8" gap around the exhaust pipe. The concept (per
my aero engineer) is to prevent the exhaust from moving much or get into the
prop, but to allow it to move a little so it can adjust itself in the muffler
due to movement and heat expansion. This restraint is well below the flex joint,
but before the pipe bends around the tailboom towards the muffler.
I have made arrangements to borrow a prop balancer, to at least eliminate that
as the culprit. I'm also going to re-pitch the prop, at the same time as checking
the runout. As mentioned, there's no runout adjustment on this prop, so it
may be moot.
One other possibility for the runout is that as the prop blades pass near the exhaust
and the rear of the cage, there is a "dead spot" or eddy current of air
that allows that blade to see a little different in-flow or out-flow, resulting
in THAT blade making a little less or more thrust at that instant, causing
an aerodynamic fore-aft vibration (as opposed to a mass balance problem).
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Wed, 7/4/18, Richard Girard <aslsa.rng@gmail.com> wrote:
Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
To: "kolb-list@matronics.com" <kolb-list@matronics.com>
Date: Wednesday, July 4, 2018, 9:34 PM
Bill, I've been
flying in front of an HKS on my trike for 11 years. It does
not shake as you describe yours. Even when I first flew it
with the carbs significantly out of synch it was smooth. The
only shaking it does is on shutdown. Since you've
already synched the carbs it should run like a sewing
machine. Sorry I can't tell you anything more than your
engine is not running properly.I looked up the info I
got from the HKS group.
"Jim
Carruthers fabricated the exhaust system for my HKS when he
did the install on my Avid. We contacted HKS in Japan
about exhaust system requirements and received a reply back
from an HKS engineer. He said the headers need to merge at
500mm for proper scavenging and the length after the
merge was not critical though he noted that installations
with excessively long pipes after the merge had experienced
rough idling issues. As far as individual headers with no
merge, there was an HKS on a Skyraider at OshKosh years ago
that had independent headers going to super trapp mufflers.
They had a difficult time getting the engine to run well and
it was way off on power. Jim routed my exhaust tubes to
merge as close to 500mm as room would allow in the cowling
and my engine runs fantastic. Right after the merge he
rolled a simple muffler can with no baffles and its pretty
quiet."
Hope this
helps,Rick
On Wed, Jul 4, 2018 at
9:43 PM, George Helton <gdhelton@gmail.com>
wrote:
George Helton <gdhelton@gmail.com>
I put vgs on my Firestar a year ago. I did the bottom of
horizontal stabilizers and the wings. They work well.
George H.
Firestar FS100, Hirth 2702
14GDH
Mesick, Michigan
gdhelton@gmail.com
Sent from my iPhone
> On Jul 4,
2018, at 6:34 PM, Bill Berle <victorbravo@sbcglobal.net>
wrote:
>
>
> Thank you all for your input and opinions... I
appreciate it.
>
> All that brightly colored junk lashed to the boom tube
is the big tow strap that we used to tie the airplane to the
Jeep. The tow strap looked big enough to lift a Sherman tank
!
>
> The 4" diameter silver tube under the tailboom is
that Swiss Muffler I was talking about. Put it in the
"woulda - coulda - shoulda worked" category.
Regardless, I do need some sort of muffler, and this one
actually works about as good as the stock HKS system, it
just doesn't make a "wow!" difference like I
thought it would.
>
> It is the tallest Kolb I've ever seen too... that
was the big plan all along, to get the wing angle up high .
Nothing was custom-built or scientifically researched about
it... it's just a set of taller steel gear legs from the
Kolb Slingshot, with 21 inch Desser bush tires. I'm
not a tall guy by any means but I can get in and out OK. The
trick is backing my butt up to the fuselage side, stepping
on the tire, and hoisting myself up onto the side of the
cockpit (longeron). It is a little easier than it looks. I
WAS wondering if I was going to have to have a one rung rope
ladder or step stool or toe strap or something to get in.
Turns out I don't need it.
>
> Using the bottom of the wing as the reference, the
airplane sits up at an 18 degree angle of attack (deck angle
actually) when on the wheels. It's even a little more
when it's on those roller skates that I use to move it
in and out of the hangar.
>
> I will indeed check the propeller runout when I
re-pitch it. It may be a moot point, there is apparently no
adjustment that I can make to it. I do not believe the
crankshaft is bent, and there is no visible damage to the
propeller hub.
>
> In my own defense, the wing pins were only in
temporarily, to get the wings out of the way of the
propeller. The aircraft was NOT going to fly or even taxi on
that day.
>
> I hope I'm not going to get any one upset or
annoyed, but I have purchased a set of vortex generators for
it, and those are going on ASAP. The VG's have now
been shown to work well on the Kolb wing design, and several
of the more experienced Kolbers seem to agree that they work
as advertised. Because I have such a high grorund angle on
mine, I would guess that my airplane would be even more
prone to stalling on landing, doing the "Kolb
Quit" maneuver. In order to get a 3 point landing I
will probably have to pull the stick farther back than with
other Kolbs, and wait a little longer before the tail comes
all the way down. Which would put me at greater risk of
that stall/drop. So the VG's will hopefully give me a
little more margin while I am learning how to fly the
airplane.
>
> Bill Berle
>
>
> ------------------------------ --------------
> On Wed, 7/4/18, Charlie England <ceengland7@gmail.com>
wrote:
>
> Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
> To: kolb-list@matronics.com
> Date: Wednesday, July 4, 2018, 2:42 PM
>
> Hey Bill,
> in that HBA link, you mentioned 1/2" of runout on
the
> prop. Did you check blade runout prior to engine start?
That
> much runout by itself could shake the engine off the
plane.
> A prop is a prop, UL or not, and if it isn't
running
> true, with exactly the same pitch on all blades,
you're
> going to get vibration.
> Charlie
> On Wed, Jul 4, 2018 at 4:15
> PM, George Helton <gdhelton@gmail.com>
> wrote:
> Well
> Bill, I guess you should have learned a valuable
lesson
> about not only Kolbs but any aircraft. If you install a
pin,
> safety it, period. If you put a bolt in, put nut on it
and
> safety it. As far as the vibration goes, youve got a
wide
> range on your idle setting. Dont worry about the rpm
so
> much as finding at sweet spot where it runs
> smoothest. Is all that stuff youve got lashed to
> the boom tube the muffler youve been telling us
about?
> Whew, sometimes our best ideas an efforts just dont
seem
> to work out. Ive been there before. I think thats
the
> tallest Kolb Ive ever seen. Im on the short side
so
> Id need a ladder just to get into the cockpit. Good
> luck! George H.Firestar FS100, Hirth
> 270214GDH Mesick,
> Michigan gdhelton@gmail.com
>
> Sent
> from my iPhone
> On Jul 4, 2018, at
> 3:03 PM, Rick Neilsen <neilsenrm@gmail.com>
> wrote:
>
> Bill
> I'm sure Larry will chime with
> his HKS knowledge.
> You need to get over that airplane
> vs Ultralight thing. Vibrations are bad news. My
redrive VW
> runs smoother at cruise RPMs than any GA airplane I
have
> ever flown.
> Most airplane engines have RPMs
> that you stay away from or pass through quickly. The
HKS is
> known for its smoothness. I have to believe that what
you
> have experienced is torsional resonance. Take the prop
off
> and it will likely run smooth a silk. The higher the
> compression and fewer the cylinders the harder it is
to
> tame. Geared engines are more prone to this issue but
some
> direct drive/prop engines have issues also.
Internal
> combustion engines will slow down on compression stroke
and
> speed up on ignition stroke. A prop wants to turn a
constant
> RPM. When a prop is subjected to these drastic changes
in
> RPM (resonance) the prop blades will whip around and
do
> nasty things and sometimes worse. All reduction drive
> engines have some form of dampening device to reduce
this
> resonance but will likely not work sufficiently at all
RPMs
> (normally have more issues at idle RPMs). It is also
> possible that engine/prop combination will not
> work.
> Worth what you paid for
> it.
> Rick NeilsenRedrive VW Powered
> MKIIIC
> On Wed, Jul
> 4, 2018 at 1:20 PM Bill Berle <victorbravo@sbcglobal.net>
> wrote:
> Greetings
> Kolbers,
>
>
>
> Yesterday we finally were able to test run the HKS
engine
> installation on my Firestar 2. The HKS engine started
right
> up and ran, but it needed carburetor adjustment. I had
a
> friend there who has experience with the HKS engine,
and he
> was kind enough to adjust the carburetors using a dual
> vacuum gauge.
>
>
>
> The one big issue I had was that the engine vibration
was
> far far more than I was ever used to seeing on an
aircraft.
> Part of this is that I'm "an airplane
guy"
> instead of "an ultralight guy", Part of it is
that
> the HKS is an opposed 2 cylinder engine with a very
high
> compression ratio (11 to 1). But part of this is also
that
> it did shake and vibrate a LOT, and I started thinking
about
> how things tend to get loose and rattle apart in a
high
> vibration environment.
>
>
>
> The one thing that really worried me is that around
idle
> speed something became resonant and the wing struts
started
> to vibrate up and down in the middle, maybe half an
inch up
> and hald an inch down versus a straight line. Aluminum
does
> NOT like this kind of vibration! Neither do fasteners.
After
> about two minutes we shut the engine down, and someone
foun
> the wing strut attachment pin (the short clevis pin) on
the
> ground next to the airplane. I had put the pin in place
from
> above without the safety pin )ground runs only). The
> vibration backed the pin completely out!
>
>
>
> Does anyone else have this kind of wing strut vibration
with
> the Kolb?
>
>
>
> Photos of the test run and adjustment wre posted here,
> scroll halfway down the page to to post # 952
>
>
>
> http://www.homebuiltairplanes.
> com/forums/showthread.php?t
28504&page=64&p=433039#
> post433039
>
>
>
> Bill Berle
>
> www.ezflaphandle.com
> - safety & performance upgrade for light aircraft
>
> www.grantstar.net
> - winning proposals for non-profit and
for-profit
> entities
>
>
>
>
>
>
==== ============================== =
-List" rel="noreferrer"
target="_blank">http://www.matronics.com/Navig
ator?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/contr
ibution
==== ============================== =
--
Blessed
are the cracked, for they shall let in the light. Groucho
Marx
Message 2
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Firestar/HKS Engine Test Run |
just as an aside on your exhaust system,any exhaust that exits near the
tube will travel along it and be drawn into the rear of the tube and
blow into the cockpit like someone is back there with a leaf blower.I
had to fashion a foam rubber plug to seal off the air flow up the tube,
6=9D thick with slits for the cables.The vg=99s are the way
to go, even with my MK3C short spring steel gear legs,the tail wheel
touches down first when I=99m solo.
G.Aman MK3C Jabiru 2200A 1060hrs
> On Jul 5, 2018, at 4:23 AM, Bill Berle <victorbravo@sbcglobal.net>
wrote:
>
<mailto:victorbravo@sbcglobal.net>>
>
> Thank you guys again for putting your brains on this :)
>
> A year ago I had contacted Jerry Olenik at Green Sky (RIP Jerry), and
he gave me a rough number of "something about 24 inches" between the
exhaust flange and the merge. That is what we built. I had actually sent
HKS Japan an e-mail and got no reply whatsoever (not even a rejection to
my request for info). That was disappointing, and not 100% professional
on their part.
>
> The exhaust has a "restraining collar" bolted to the bolt that holds
the tailboom tube to the fuselage at the back of the cage. This
restraint is like a giant Adel clamp, except it has 1/8" gap around the
exhaust pipe. The concept (per my aero engineer) is to prevent the
exhaust from moving much or get into the prop, but to allow it to move a
little so it can adjust itself in the muffler due to movement and heat
expansion. This restraint is well below the flex joint, but before the
pipe bends around the tailboom towards the muffler.
>
> I have made arrangements to borrow a prop balancer, to at least
eliminate that as the culprit. I'm also going to re-pitch the prop, at
the same time as checking the runout. As mentioned, there's no runout
adjustment on this prop, so it may be moot.
>
> One other possibility for the runout is that as the prop blades pass
near the exhaust and the rear of the cage, there is a "dead spot" or
eddy current of air that allows that blade to see a little different
in-flow or out-flow, resulting in THAT blade making a little less or
more thrust at that instant, causing an aerodynamic fore-aft vibration
(as opposed to a mass balance problem).
>
>
> Bill Berle
> www.ezflaphandle.com <http://www.ezflaphandle.com/> - safety &
performance upgrade for light aircraft
> www.grantstar.net <http://www.grantstar.net/> - winning
proposals for non-profit and for-profit entities
>
> --------------------------------------------
> On Wed, 7/4/18, Richard Girard <aslsa.rng@gmail.com
<mailto:aslsa.rng@gmail.com>> wrote:
>
> Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
> To: "kolb-list@matronics.com <mailto:kolb-list@matronics.com>"
<kolb-list@matronics.com <mailto:kolb-list@matronics.com>>
> Date: Wednesday, July 4, 2018, 9:34 PM
>
> Bill, I've been
> flying in front of an HKS on my trike for 11 years. It does
> not shake as you describe yours. Even when I first flew it
> with the carbs significantly out of synch it was smooth. The
> only shaking it does is on shutdown. Since you've
> already synched the carbs it should run like a sewing
> machine. Sorry I can't tell you anything more than your
> engine is not running properly.I looked up the info I
> got from the HKS group.
> " Jim
> Carruthers fabricated the exhaust system for my HKS when he
> did the install on my Avid. We contacted HKS in Japan
> about exhaust system requirements and received a reply back
> from an HKS engineer. He said the headers need to merge at
> 500mm for proper scavenging and the length after the
> merge was not critical though he noted that installations
> with excessively long pipes after the merge had experienced
> rough idling issues. As far as individual headers with no
> merge, there was an HKS on a Skyraider at OshKosh years ago
> that had independent headers going to super trapp mufflers.
> They had a difficult time getting the engine to run well and
> it was way off on power. Jim routed my exhaust tubes to
> merge as close to 500mm as room would allow in the cowling
> and my engine runs fantastic. Right after the merge he
> rolled a simple muffler can with no baffles and its pretty
> quiet."
> Hope this
> helps,Rick
>
>
>
>
>
> On Wed, Jul 4, 2018 at
> 9:43 PM, George Helton <gdhelton@gmail.com
<mailto:gdhelton@gmail.com>>
> wrote:
> George Helton <gdhelton@gmail.com <mailto:gdhelton@gmail.com>>
>
>
>
> I put vg=99s on my Firestar a year ago. I did the bottom of
> horizontal stabilizers and the wings. They work well.
>
> George H.
>
> Firestar FS100, Hirth 2702
>
> 14GDH
>
> Mesick, Michigan
>
> gdhelton@gmail.com <mailto:gdhelton@gmail.com>
>
>
>
> Sent from my iPhone
>
>
>
>> On Jul 4,
> 2018, at 6:34 PM, Bill Berle <victorbravo@sbcglobal.net
<mailto:victorbravo@sbcglobal.net>>
> wrote:
>
>>
>
<victorbravo@sbcglobal.net>
>
>>
>
>> Thank you all for your input and opinions... I
> appreciate it.
>
>>
>
>> All that brightly colored junk lashed to the boom tube
> is the big tow strap that we used to tie the airplane to the
> Jeep. The tow strap looked big enough to lift a Sherman tank
> !
>
>>
>
>> The 4" diameter silver tube under the tailboom is
> that Swiss Muffler I was talking about. Put it in the
> "woulda - coulda - shoulda worked" category.
> Regardless, I do need some sort of muffler, and this one
> actually works about as good as the stock HKS system, it
> just doesn't make a "wow!" difference like I
> thought it would.
>
>>
>
>> It is the tallest Kolb I've ever seen too... that
> was the big plan all along, to get the wing angle up high .
> Nothing was custom-built or scientifically researched about
> it... it's just a set of taller steel gear legs from the
> Kolb Slingshot, with 21 inch Desser bush tires. I'm
> not a tall guy by any means but I can get in and out OK. The
> trick is backing my butt up to the fuselage side, stepping
> on the tire, and hoisting myself up onto the side of the
> cockpit (longeron). It is a little easier than it looks. I
> WAS wondering if I was going to have to have a one rung rope
> ladder or step stool or toe strap or something to get in.
> Turns out I don't need it.
>
>>
>
>> Using the bottom of the wing as the reference, the
> airplane sits up at an 18 degree angle of attack (deck angle
> actually) when on the wheels. It's even a little more
> when it's on those roller skates that I use to move it
> in and out of the hangar.
>
>>
>
>> I will indeed check the propeller runout when I
> re-pitch it. It may be a moot point, there is apparently no
> adjustment that I can make to it. I do not believe the
> crankshaft is bent, and there is no visible damage to the
> propeller hub.
>
>>
>
>> In my own defense, the wing pins were only in
> temporarily, to get the wings out of the way of the
> propeller. The aircraft was NOT going to fly or even taxi on
> that day.
>
>>
>
>> I hope I'm not going to get any one upset or
> annoyed, but I have purchased a set of vortex generators for
> it, and those are going on ASAP. The VG's have now
> been shown to work well on the Kolb wing design, and several
> of the more experienced Kolbers seem to agree that they work
> as advertised. Because I have such a high grorund angle on
> mine, I would guess that my airplane would be even more
> prone to stalling on landing, doing the "Kolb
> Quit" maneuver. In order to get a 3 point landing I
> will probably have to pull the stick farther back than with
> other Kolbs, and wait a little longer before the tail comes
> all the way down. Which would put me at greater risk of
> that stall/drop. So the VG's will hopefully give me a
> little more margin while I am learning how to fly the
> airplane.
>
>>
>
>> Bill Berle
>
>>
>
>>
>
>> ------------------------------ --------------
>
>> On Wed, 7/4/18, Charlie England <ceengland7@gmail.com>
> wrote:
>
>>
>
>> Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
>
>> To: kolb-list@matronics.com
>
>> Date: Wednesday, July 4, 2018, 2:42 PM
>
>>
>
>> Hey Bill,
>
>> in that HBA link, you mentioned 1/2" of runout on
> the
>
>> prop. Did you check blade runout prior to engine start?
> That
>
>> much runout by itself could shake the engine off the
> plane.
>
>> A prop is a prop, UL or not, and if it isn't
> running
>
>> true, with exactly the same pitch on all blades,
> you're
>
>> going to get vibration.
>
>> Charlie
>
>> On Wed, Jul 4, 2018 at 4:15
>
>> PM, George Helton <gdhelton@gmail.com>
>
>> wrote:
>
>> Well
>
>> Bill, I guess you should have learned a valuable
> lesson
>
>> about not only Kolbs but any aircraft. If you install a
> pin,
>
>> safety it, period. If you put a bolt in, put nut on it
> and
>
>> safety it. As far as the vibration goes, you=99ve got a
> wide
>
>> range on your idle setting. Don=99t worry about the rpm
> so
>
>> much as finding at sweet spot where it runs
>
>> smoothest. Is all that stuff you=99ve got lashed to
>
>> the boom tube the muffler you=99ve been telling us
> about?
>
>> Whew, sometimes our best ideas an efforts just don=99t
> seem
>
>> to work out. I=99ve been there before. I think that=99s
> the
>
>> tallest Kolb I=99ve ever seen. I=99m on the short side
> so
>
>> I=99d need a ladder just to get into the cockpit. Good
>
>> luck! George H.Firestar FS100, Hirth
>
>> 270214GDH Mesick,
>
>> Michigan gdhelton@gmail.com
>
>>
>
>> Sent
>
>> from my iPhone
>
>> On Jul 4, 2018, at
>
>> 3:03 PM, Rick Neilsen <neilsenrm@gmail.com>
>
>> wrote:
>
>>
>
>> Bill
>
>> I'm sure Larry will chime with
>
>> his HKS knowledge.
>
>> You need to get over that airplane
>
>> vs Ultralight thing. Vibrations are bad news. My
> redrive VW
>
>> runs smoother at cruise RPMs than any GA airplane I
> have
>
>> ever flown.
>
>> Most airplane engines have RPMs
>
>> that you stay away from or pass through quickly. The
> HKS is
>
>> known for its smoothness. I have to believe that what
> you
>
>> have experienced is torsional resonance. Take the prop
> off
>
>> and it will likely run smooth a silk. The higher the
>
>> compression and fewer the cylinders the harder it is
> to
>
>> tame. Geared engines are more prone to this issue but
> some
>
>> direct drive/prop engines have issues also.
> Internal
>
>> combustion engines will slow down on compression stroke
> and
>
>> speed up on ignition stroke. A prop wants to turn a
> constant
>
>> RPM. When a prop is subjected to these drastic changes
> in
>
>> RPM (resonance) the prop blades will whip around and
> do
>
>> nasty things and sometimes worse. All reduction drive
>
>> engines have some form of dampening device to reduce
> this
>
>> resonance but will likely not work sufficiently at all
> RPMs
>
>> (normally have more issues at idle RPMs). It is also
>
>> possible that engine/prop combination will not
>
>> work.
>
>> Worth what you paid for
>
>> it.
>
>> Rick NeilsenRedrive VW Powered
>
>> MKIIIC
>
>> On Wed, Jul
>
>> 4, 2018 at 1:20 PM Bill Berle <victorbravo@sbcglobal.net>
>
>> wrote:
>
>> Greetings
>
>> Kolbers,
>
>>
>
>>
>
>>
>
>> Yesterday we finally were able to test run the HKS
> engine
>
>> installation on my Firestar 2. The HKS engine started
> right
>
>> up and ran, but it needed carburetor adjustment. I had
> a
>
>> friend there who has experience with the HKS engine,
> and he
>
>> was kind enough to adjust the carburetors using a dual
>
>> vacuum gauge.
>
>>
>
>>
>
>>
>
>> The one big issue I had was that the engine vibration
> was
>
>> far far more than I was ever used to seeing on an
> aircraft.
>
>> Part of this is that I'm "an airplane
> guy"
>
>> instead of "an ultralight guy", Part of it is
> that
>
>> the HKS is an opposed 2 cylinder engine with a very
> high
>
>> compression ratio (11 to 1). But part of this is also
> that
>
>> it did shake and vibrate a LOT, and I started thinking
> about
>
>> how things tend to get loose and rattle apart in a
> high
>
>> vibration environment.
>
>>
>
>>
>
>>
>
>> The one thing that really worried me is that around
> idle
>
>> speed something became resonant and the wing struts
> started
>
>> to vibrate up and down in the middle, maybe half an
> inch up
>
>> and hald an inch down versus a straight line. Aluminum
> does
>
>> NOT like this kind of vibration! Neither do fasteners.
> After
>
>> about two minutes we shut the engine down, and someone
> foun
>
>> the wing strut attachment pin (the short clevis pin) on
> the
>
>> ground next to the airplane. I had put the pin in place
> from
>
>> above without the safety pin )ground runs only). The
>
>> vibration backed the pin completely out!
>
>>
>
>>
>
>>
>
>> Does anyone else have this kind of wing strut vibration
> with
>
>> the Kolb?
>
>>
>
>>
>
>>
>
>> Photos of the test run and adjustment wre posted here,
>
>> scroll halfway down the page to to post # 952
>
>>
>
>>
>
>>
>
>> http://www.homebuiltairplanes.
>
>> com/forums/showthread.php?t
> 28504&page=64&p=433039#
>
>> post433039
>
>>
>
>>
>
>>
>
>> Bill Berle
>
>>
>
>> www.ezflaphandle.com
>
>
>> - safety & performance upgrade for light aircraft
>
>>
>
>> www.grantstar.net
>
>> - winning proposals for non-profit and
> for-profit
>
>> entities
>
>>
>
>>
>
>>
>
>>
>
>>
>
>>
>
>
>
> ==== ====================
========== =
>
> -List" rel="noreferrer"
> target="_blank">http://www.matronics.com/Navig
<http://www.matronics.com/Navig>
> ator?Kolb-List
>
> ==== ====================
========== =
>
> FORUMS -
>
> eferrer"
> target="_blank">http://forums.matronics.com
<http://forums.matronics.com/>
>
> ==== ====================
========== =
>
> WIKI -
>
> errer"
> target="_blank">http://wiki.matronics.com
<http://wiki.matronics.com/>
>
> ==== ====================
========== =
>
> b Site -
>
> -Matt Dralle, List Admin.
>
> rel="noreferrer"
> target="_blank">http://www.matronics.com/contr
<http://www.matronics.com/contr>
> ibution
>
> ==== ====================
========== =
>
>
>
>
>
>
>
>
>
>
> --
> =9CBlessed
> are the cracked, for they shall let in the light.=9D Groucho
> Marx
>
>
>
Message 3
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Firestar/HKS Engine Test Run |
I've not had a runout adjustment feature on any prop I've ever used, but
with heavier homebuilts running Lycs & Conts, the SOP is to measure
tracking, and shim between the engine's prop flange and the prop's mating
surface to get equal tracking. Often, a strip of typing paper around the
bolt circle arc on one side is enough to move the tip close to 1/8". I
don't recall your prop brand/model, but if you're seeing 1/2" of static
runout on a prop with a machined hub and blades made in molds, you could
have either a defective prop, or a bent flange. On the other hand, if it's
just out that much while running, it could just be balance, or unequal
pitch among the blades, or slight runout made worse by running the engine.
Static balance of the prop is a good first step, and relatively easy to do.
Dynamic balance is better if you can beg/borrow a balancer, but if static
balance and tracking are not right, the dynamic balancer may not be able to
help you.
Pusher props do see weird airflow; that's one reason fast pushers (VariEze,
etc) don't have quite the speed gains over tractor designs that the
calculations would suggest. But I've never heard of it causing such drastic
prop oscillations.
Charlie
On Thu, Jul 5, 2018 at 3:23 AM, Bill Berle <victorbravo@sbcglobal.net>
wrote:
>
> Thank you guys again for putting your brains on this :)
>
> A year ago I had contacted Jerry Olenik at Green Sky (RIP Jerry), and he
> gave me a rough number of "something about 24 inches" between the exhaust
> flange and the merge. That is what we built. I had actually sent HKS Japan
> an e-mail and got no reply whatsoever (not even a rejection to my request
> for info). That was disappointing, and not 100% professional on their part.
>
> The exhaust has a "restraining collar" bolted to the bolt that holds the
> tailboom tube to the fuselage at the back of the cage. This restraint is
> like a giant Adel clamp, except it has 1/8" gap around the exhaust pipe.
> The concept (per my aero engineer) is to prevent the exhaust from moving
> much or get into the prop, but to allow it to move a little so it can
> adjust itself in the muffler due to movement and heat expansion. This
> restraint is well below the flex joint, but before the pipe bends around
> the tailboom towards the muffler.
>
> I have made arrangements to borrow a prop balancer, to at least eliminate
> that as the culprit. I'm also going to re-pitch the prop, at the same time
> as checking the runout. As mentioned, there's no runout adjustment on this
> prop, so it may be moot.
>
> One other possibility for the runout is that as the prop blades pass near
> the exhaust and the rear of the cage, there is a "dead spot" or eddy
> current of air that allows that blade to see a little different in-flow or
> out-flow, resulting in THAT blade making a little less or more thrust at
> that instant, causing an aerodynamic fore-aft vibration (as opposed to a
> mass balance problem).
>
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
>
> --------------------------------------------
> On Wed, 7/4/18, Richard Girard <aslsa.rng@gmail.com> wrote:
>
> Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
> To: "kolb-list@matronics.com" <kolb-list@matronics.com>
> Date: Wednesday, July 4, 2018, 9:34 PM
>
> Bill, I've been
> flying in front of an HKS on my trike for 11 years. It does
> not shake as you describe yours. Even when I first flew it
> with the carbs significantly out of synch it was smooth. The
> only shaking it does is on shutdown. Since you've
> already synched the carbs it should run like a sewing
> machine. Sorry I can't tell you anything more than your
> engine is not running properly.I looked up the info I
> got from the HKS group.
> " Jim
> Carruthers fabricated the exhaust system for my HKS when he
> did the install on my Avid. We contacted HKS in Japan
> about exhaust system requirements and received a reply back
> from an HKS engineer. He said the headers need to merge at
> 500mm for proper scavenging and the length after the
> merge was not critical though he noted that installations
> with excessively long pipes after the merge had experienced
> rough idling issues. As far as individual headers with no
> merge, there was an HKS on a Skyraider at OshKosh years ago
> that had independent headers going to super trapp mufflers.
> They had a difficult time getting the engine to run well and
> it was way off on power. Jim routed my exhaust tubes to
> merge as close to 500mm as room would allow in the cowling
> and my engine runs fantastic. Right after the merge he
> rolled a simple muffler can with no baffles and its pretty
> quiet."
> Hope this
> helps,Rick
>
Message 4
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Firestar/HKS Engine Test Run |
Bill/Kolbers:
Just a guess. Your exhaust system design is probably causing the
vibration and the engine mounts are not able to absorb them, thus
transmitting then to the airframe. With what little I know of your
Kolb, I=99d say it is a combination of unconventional exhaust and
engine mounts.
My philosophy is KISS (keep it simple stupid). Your exhaust system goes
way beyond KISS.
If it can be disconnected at the =9CY=9D it might be a good
idea to do that. Then test the engine isolated from all that exhaust
plumbing.
I believe everyone has given you good advice.
I=99m guessing you are trying to silence the HKS with the fancy
exhaust. I think you must remember that the prop makes much more noise
than the engine. So...when it is all over and done, when your engine is
silenced, you still have to contend with the whiny prop noise, a trade
more of ultralights.
I doubt the exhaust pipe in front of the prop is creating enough dead
space to cause rough running. Kolbs have a lot more in front of the
prop than just a small exhaust pipe.
Just my early morning thoughts. Take it for what it is worth.
High speed, low drag! ;-)
John h
Atlanta, GA
-----Original Message-----
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Bill Berle
Sent: Thursday, July 5, 2018 3:24 AM.
Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
<mailto:victorbravo@sbcglobal.net> victorbravo@sbcglobal.net>
Thank you guys again for putting your brains on this :)
A year ago I had contacted Jerry Olenik at Green Sky (RIP Jerry), and
he gave me a rough number of "something about 24 inches" between the
exhaust flange and the merge. That is what we built. I had actually sent
HKS Japan an e-mail and got no reply whatsoever (not even a rejection to
my request for info). That was disappointing, and not 100% professional
on their part.
The exhaust has a "restraining collar" bolted to the bolt that holds the
tailboom tube to the fuselage at the back of the cage. This restraint is
like a giant Adel clamp, except it has 1/8" gap around the exhaust pipe.
The concept (per my aero engineer) is to prevent the exhaust from moving
much or get into the prop, but to allow it to move a little so it can
adjust itself in the muffler due to movement and heat expansion. This
restraint is well below the flex joint, but before the pipe bends around
the tailboom towards the muffler.
I have made arrangements to borrow a prop balancer, to at least
eliminate that as the culprit. I'm also going to re-pitch the prop, at
the same time as checking the runout. As mentioned, there's no runout
adjustment on this prop, so it may be moot.
One other possibility for the runout is that as the prop blades pass
near the exhaust and the rear of the cage, there is a "dead spot" or
eddy current of air that allows that blade to see a little different
in-flow or out-flow, resulting in THAT blade making a little less or
more thrust at that instant, causing an aerodynamic fore-aft vibration
(as opposed to a mass balance problem).
Bill Berle
<http://www.ezflaphandle.com> www.ezflaphandle.com - safety &
performance upgrade for light aircraft <http://www.grantstar.net>
www.grantstar.net - winning proposals for non-profit and
for-profit entities
--------------------------------------------
On Wed, 7/4/18, Richard Girard < <mailto:aslsa.rng@gmail.com>
aslsa.rng@gmail.com> wrote:
Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
<mailto:kolb-list@matronics.com> kolb-list@matronics.com>
Bill, I've been
flying in front of an HKS on my trike for 11 years. It does not shake
as you describe yours. Even when I first flew it with the carbs
significantly out of synch it was smooth. The only shaking it does is
on shutdown. Since you've already synched the carbs it should run like
a sewing machine. Sorry I can't tell you anything more than your
engine is not running properly.I looked up the info I got from the HKS
group.
" Jim
Carruthers fabricated the exhaust system for my HKS when he did the
install on my Avid. We contacted HKS in Japan about exhaust system
requirements and received a reply back from an HKS engineer. He said
the headers need to merge at 500mm for proper scavenging and the length
after the merge was not critical though he noted that installations
with excessively long pipes after the merge had experienced rough
idling issues. As far as individual headers with no merge, there was an
HKS on a Skyraider at OshKosh years ago that had independent headers
going to super trapp mufflers.
They had a difficult time getting the engine to run well and it was way
off on power. Jim routed my exhaust tubes to merge as close to 500mm as
room would allow in the cowling and my engine runs fantastic. Right
after the merge he rolled a simple muffler can with no baffles and its
pretty quiet."
Hope this
helps,Rick
On Wed, Jul 4, 2018 at
9:43 PM, George Helton < <mailto:gdhelton@gmail.com> gdhelton@gmail.com>
wrote:
George Helton < <mailto:gdhelton@gmail.com> gdhelton@gmail.com>
I put vg=99s on my Firestar a year ago. I did the bottom of
horizontal stabilizers and the wings. They work well.
George H.
Firestar FS100, Hirth 2702
14GDH
Mesick, Michigan
<mailto:gdhelton@gmail.com> gdhelton@gmail.com
Sent from my iPhone
> On Jul 4,
2018, at 6:34 PM, Bill Berle < <mailto:victorbravo@sbcglobal.net>
victorbravo@sbcglobal.net>
wrote:
>
<mailto:victorbravo@sbcglobal.net> victorbravo@sbcglobal.net>
>
> Thank you all for your input and opinions... I appreciate it.
>
> All that brightly colored junk lashed to the boom tube is the big
tow strap that we used to tie the airplane to the Jeep. The tow strap
looked big enough to lift a Sherman tank !
>
> The 4" diameter silver tube under the tailboom is that Swiss Muffler
I was talking about. Put it in the "woulda - coulda - shoulda worked"
category.
Regardless, I do need some sort of muffler, and this one actually works
about as good as the stock HKS system, it just doesn't make a "wow!"
difference like I thought it would.
>
> It is the tallest Kolb I've ever seen too... that was the big plan
all along, to get the wing angle up high .
Nothing was custom-built or scientifically researched about it... it's
just a set of taller steel gear legs from the Kolb Slingshot, with 21
inch Desser bush tires. I'm not a tall guy by any means but I can get
in and out OK. The trick is backing my butt up to the fuselage side,
stepping on the tire, and hoisting myself up onto the side of the
cockpit (longeron). It is a little easier than it looks. I WAS
wondering if I was going to have to have a one rung rope ladder or step
stool or toe strap or something to get in.
Turns out I don't need it.
>
> Using the bottom of the wing as the reference, the airplane sits up
at an 18 degree angle of attack (deck angle
actually) when on the wheels. It's even a little more when it's on
those roller skates that I use to move it in and out of the hangar.
>
> I will indeed check the propeller runout when I re-pitch it. It may
be a moot point, there is apparently no adjustment that I can make to
it. I do not believe the crankshaft is bent, and there is no visible
damage to the propeller hub.
>
> In my own defense, the wing pins were only in temporarily, to get
the wings out of the way of the propeller. The aircraft was NOT going
to fly or even taxi on that day.
>
> I hope I'm not going to get any one upset or annoyed, but I have
purchased a set of vortex generators for it, and those are going on
ASAP. The VG's have now been shown to work well on the Kolb wing
design, and several of the more experienced Kolbers seem to agree that
they work as advertised. Because I have such a high grorund angle on
mine, I would guess that my airplane would be even more prone to
stalling on landing, doing the "Kolb Quit" maneuver. In order to get a
3 point landing I will probably have to pull the stick farther back
than with other Kolbs, and wait a little longer before the tail comes
all the way down. Which would put me at greater risk of that
stall/drop. So the VG's will hopefully give me a little more margin
while I am learning how to fly the airplane.
>
> Bill Berle
>
>
> ------------------------------ --------------
> On Wed, 7/4/18, Charlie England < <mailto:ceengland7@gmail.com>
ceengland7@gmail.com>
wrote:
>
> Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
> To: <mailto:kolb-list@matronics.com> kolb-list@matronics.com
> Date: Wednesday, July 4, 2018, 2:42 PM
>
> Hey Bill,
> in that HBA link, you mentioned 1/2" of runout on the
> prop. Did you check blade runout prior to engine start?
That
> much runout by itself could shake the engine off the plane.
> A prop is a prop, UL or not, and if it isn't running
> true, with exactly the same pitch on all blades, you're
> going to get vibration.
> Charlie
> On Wed, Jul 4, 2018 at 4:15
> PM, George Helton < <mailto:gdhelton@gmail.com> gdhelton@gmail.com>
> wrote:
> Well
> Bill, I guess you should have learned a valuable lesson
> about not only Kolbs but any aircraft. If you install a pin,
> safety it, period. If you put a bolt in, put nut on it and
> safety it. As far as the vibration goes, you=99ve got a wide
> range on your idle setting. Don=99t worry about the rpm so
> much as finding at sweet spot where it runs
> smoothest. Is all that stuff you=99ve got lashed to
> the boom tube the muffler you=99ve been telling us about?
> Whew, sometimes our best ideas an efforts just don=99t seem
> to work out. I=99ve been there before. I think that=99s
the
> tallest Kolb I=99ve ever seen. I=99m on the short side
so
> I=99d need a ladder just to get into the cockpit. Good
> luck! George H.Firestar FS100, Hirth
> 270214GDH Mesick,
> Michigan <mailto:gdhelton@gmail.com> gdhelton@gmail.com
>
> Sent
> from my iPhone
> On Jul 4, 2018, at
> 3:03 PM, Rick Neilsen < <mailto:neilsenrm@gmail.com>
neilsenrm@gmail.com>
> wrote:
>
> Bill
> I'm sure Larry will chime with
> his HKS knowledge.
> You need to get over that airplane
> vs Ultralight thing. Vibrations are bad news. My redrive VW
> runs smoother at cruise RPMs than any GA airplane I have
> ever flown.
> Most airplane engines have RPMs
> that you stay away from or pass through quickly. The HKS is
> known for its smoothness. I have to believe that what you
> have experienced is torsional resonance. Take the prop off
> and it will likely run smooth a silk. The higher the
> compression and fewer the cylinders the harder it is to
> tame. Geared engines are more prone to this issue but some
> direct drive/prop engines have issues also.
Internal
> combustion engines will slow down on compression stroke and
> speed up on ignition stroke. A prop wants to turn a constant
> RPM. When a prop is subjected to these drastic changes in
> RPM (resonance) the prop blades will whip around and do
> nasty things and sometimes worse. All reduction drive
> engines have some form of dampening device to reduce this
> resonance but will likely not work sufficiently at all RPMs
> (normally have more issues at idle RPMs). It is also
> possible that engine/prop combination will not
> work.
> Worth what you paid for
> it.
> Rick NeilsenRedrive VW Powered
> MKIIIC
> On Wed, Jul
> 4, 2018 at 1:20 PM Bill Berle < <mailto:victorbravo@sbcglobal.net>
victorbravo@sbcglobal.net>
> wrote:
> Greetings
> Kolbers,
>
>
>
> Yesterday we finally were able to test run the HKS engine
> installation on my Firestar 2. The HKS engine started right
> up and ran, but it needed carburetor adjustment. I had a
> friend there who has experience with the HKS engine, and he
> was kind enough to adjust the carburetors using a dual
> vacuum gauge.
>
>
>
> The one big issue I had was that the engine vibration was
> far far more than I was ever used to seeing on an aircraft.
> Part of this is that I'm "an airplane guy"
> instead of "an ultralight guy", Part of it is that
> the HKS is an opposed 2 cylinder engine with a very high
> compression ratio (11 to 1). But part of this is also that
> it did shake and vibrate a LOT, and I started thinking about
> how things tend to get loose and rattle apart in a high
> vibration environment.
>
>
>
> The one thing that really worried me is that around idle
> speed something became resonant and the wing struts started
> to vibrate up and down in the middle, maybe half an inch up
> and hald an inch down versus a straight line. Aluminum does
> NOT like this kind of vibration! Neither do fasteners.
After
> about two minutes we shut the engine down, and someone foun
> the wing strut attachment pin (the short clevis pin) on the
> ground next to the airplane. I had put the pin in place from
> above without the safety pin )ground runs only). The
> vibration backed the pin completely out!
>
>
>
> Does anyone else have this kind of wing strut vibration with
> the Kolb?
>
>
>
> Photos of the test run and adjustment wre posted here,
> scroll halfway down the page to to post # 952
>
>
>
> <http://www.homebuiltairplanes> http://www.homebuiltairplanes.
> com/forums/showthread.php?t
28504&page=64&p=433039#
> post433039
>
>
>
> Bill Berle
>
> <http://www.ezflaphandle.com> www.ezflaphandle.com
> - safety & performance upgrade for light aircraft
>
> <http://www.grantstar.net> www.grantstar.net
> - winning proposals for non-profit and for-profit
> entities
>
>
>
>
>
>
====
===== =
-List" rel="noreferrer"
target="_blank"> <http://www.matronics.com/Navig>
http://www.matronics.com/Navig
ator?Kolb-List
====
===== =
FORUMS -
eferrer"
target="_blank"> <http://forums.matronics.com>
http://forums.matronics.com
====
===== =
WIKI -
errer"
target="_blank"> <http://wiki.matronics.com> http://wiki.matronics.com
====
===== =
b Site -
-Matt Dralle, List Admin.
rel="noreferrer"
target="_blank"> <http://www.matronics.com/contr>
http://www.matronics.com/contr
ibution
====
===== =
--
=9CBlessed
are the cracked, for they shall let in the light.=9D Groucho
Marx
http://www.matronics.com/Navigator?Kolb-List
http://www.matronics.com/contribution
Message 5
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Firestar/HKS Engine Test Run |
Gary:
Good info and remainder on carbon monoxide. You are absolutely correct,
the tail boom is a leaf blower directed into the cockpit.
Don=99t take a chance on CO2 poisoning.
John h
Atlanta, GA
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Gary Aman
Sent: Thursday, July 5, 2018 8:01 AM
Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
just as an aside on your exhaust system,any exhaust that exits near the
tube will travel along it and be drawn into the rear of the tube and
blow into the cockpit like someone is back there with a leaf blower.I
had to fashion a foam rubber plug to seal off the air flow up the tube,
6=9D thick with slits for the cables.The vg=99s are the way
to go, even with my MK3C short spring steel gear legs,the tail wheel
touches down first when I=99m solo.
G.Aman MK3C Jabiru 2200A 1060hrs
On Jul 5, 2018, at 4:23 AM, Bill Berle <victorbravo@sbcglobal.net>
wrote:
<mailto:victorbravo@sbcglobal.net> victorbravo@sbcglobal.net>
Thank you guys again for putting your brains on this :)
A year ago I had contacted Jerry Olenik at Green Sky (RIP Jerry), and
he gave me a rough number of "something about 24 inches" between the
exhaust flange and the merge. That is what we built. I had actually sent
HKS Japan an e-mail and got no reply whatsoever (not even a rejection to
my request for info). That was disappointing, and not 100% professional
on their part.
The exhaust has a "restraining collar" bolted to the bolt that holds the
tailboom tube to the fuselage at the back of the cage. This restraint is
like a giant Adel clamp, except it has 1/8" gap around the exhaust pipe.
The concept (per my aero engineer) is to prevent the exhaust from moving
much or get into the prop, but to allow it to move a little so it can
adjust itself in the muffler due to movement and heat expansion. This
restraint is well below the flex joint, but before the pipe bends around
the tailboom towards the muffler.
I have made arrangements to borrow a prop balancer, to at least
eliminate that as the culprit. I'm also going to re-pitch the prop, at
the same time as checking the runout. As mentioned, there's no runout
adjustment on this prop, so it may be moot.
One other possibility for the runout is that as the prop blades pass
near the exhaust and the rear of the cage, there is a "dead spot" or
eddy current of air that allows that blade to see a little different
in-flow or out-flow, resulting in THAT blade making a little less or
more thrust at that instant, causing an aerodynamic fore-aft vibration
(as opposed to a mass balance problem).
Bill Berle
<http://www.ezflaphandle.com/> www.ezflaphandle.com - safety &
performance upgrade for light aircraft
<http://www.grantstar.net/> www.grantstar.net - winning
proposals for non-profit and for-profit entities
--------------------------------------------
On Wed, 7/4/18, Richard Girard < <mailto:aslsa.rng@gmail.com>
aslsa.rng@gmail.com> wrote:
Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
<mailto:kolb-list@matronics.com> kolb-list@matronics.com>
Bill, I've been
flying in front of an HKS on my trike for 11 years. It does
not shake as you describe yours. Even when I first flew it
with the carbs significantly out of synch it was smooth. The
only shaking it does is on shutdown. Since you've
already synched the carbs it should run like a sewing
machine. Sorry I can't tell you anything more than your
engine is not running properly.I looked up the info I
got from the HKS group.
" Jim
Carruthers fabricated the exhaust system for my HKS when he
did the install on my Avid. We contacted HKS in Japan
about exhaust system requirements and received a reply back
from an HKS engineer. He said the headers need to merge at
500mm for proper scavenging and the length after the
merge was not critical though he noted that installations
with excessively long pipes after the merge had experienced
rough idling issues. As far as individual headers with no
merge, there was an HKS on a Skyraider at OshKosh years ago
that had independent headers going to super trapp mufflers.
They had a difficult time getting the engine to run well and
it was way off on power. Jim routed my exhaust tubes to
merge as close to 500mm as room would allow in the cowling
and my engine runs fantastic. Right after the merge he
rolled a simple muffler can with no baffles and its pretty
quiet."
Hope this
helps,Rick
On Wed, Jul 4, 2018 at
9:43 PM, George Helton < <mailto:gdhelton@gmail.com> gdhelton@gmail.com>
wrote:
George Helton < <mailto:gdhelton@gmail.com> gdhelton@gmail.com>
I put vg=99s on my Firestar a year ago. I did the bottom of
horizontal stabilizers and the wings. They work well.
George H.
Firestar FS100, Hirth 2702
14GDH
Mesick, Michigan
<mailto:gdhelton@gmail.com> gdhelton@gmail.com
Sent from my iPhone
On Jul 4,
2018, at 6:34 PM, Bill Berle < <mailto:victorbravo@sbcglobal.net>
victorbravo@sbcglobal.net>
wrote:
Thank you all for your input and opinions... I
appreciate it.
All that brightly colored junk lashed to the boom tube
is the big tow strap that we used to tie the airplane to the
Jeep. The tow strap looked big enough to lift a Sherman tank
!
The 4" diameter silver tube under the tailboom is
that Swiss Muffler I was talking about. Put it in the
"woulda - coulda - shoulda worked" category.
Regardless, I do need some sort of muffler, and this one
actually works about as good as the stock HKS system, it
just doesn't make a "wow!" difference like I
thought it would.
It is the tallest Kolb I've ever seen too... that
was the big plan all along, to get the wing angle up high .
Nothing was custom-built or scientifically researched about
it... it's just a set of taller steel gear legs from the
Kolb Slingshot, with 21 inch Desser bush tires. I'm
not a tall guy by any means but I can get in and out OK. The
trick is backing my butt up to the fuselage side, stepping
on the tire, and hoisting myself up onto the side of the
cockpit (longeron). It is a little easier than it looks. I
WAS wondering if I was going to have to have a one rung rope
ladder or step stool or toe strap or something to get in.
Turns out I don't need it.
Using the bottom of the wing as the reference, the
airplane sits up at an 18 degree angle of attack (deck angle
actually) when on the wheels. It's even a little more
when it's on those roller skates that I use to move it
in and out of the hangar.
I will indeed check the propeller runout when I
re-pitch it. It may be a moot point, there is apparently no
adjustment that I can make to it. I do not believe the
crankshaft is bent, and there is no visible damage to the
propeller hub.
In my own defense, the wing pins were only in
temporarily, to get the wings out of the way of the
propeller. The aircraft was NOT going to fly or even taxi on
that day.
I hope I'm not going to get any one upset or
annoyed, but I have purchased a set of vortex generators for
it, and those are going on ASAP. The VG's have now
been shown to work well on the Kolb wing design, and several
of the more experienced Kolbers seem to agree that they work
as advertised. Because I have such a high grorund angle on
mine, I would guess that my airplane would be even more
prone to stalling on landing, doing the "Kolb
Quit" maneuver. In order to get a 3 point landing I
will probably have to pull the stick farther back than with
other Kolbs, and wait a little longer before the tail comes
all the way down. Which would put me at greater risk of
that stall/drop. So the VG's will hopefully give me a
little more margin while I am learning how to fly the
airplane.
Bill Berle
------------------------------ --------------
On Wed, 7/4/18, Charlie England <ceengland7@gmail.com>
wrote:
Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
Hey Bill,
in that HBA link, you mentioned 1/2" of runout on
the
prop. Did you check blade runout prior to engine start?
That
much runout by itself could shake the engine off the
plane.
A prop is a prop, UL or not, and if it isn't
running
true, with exactly the same pitch on all blades,
you're
going to get vibration.
Charlie
On Wed, Jul 4, 2018 at 4:15
PM, George Helton <gdhelton@gmail.com>
wrote:
Well
Bill, I guess you should have learned a valuable
lesson
about not only Kolbs but any aircraft. If you install a
pin,
safety it, period. If you put a bolt in, put nut on it
and
safety it. As far as the vibration goes, you=99ve got a
wide
range on your idle setting. Don=99t worry about the rpm
so
much as finding at sweet spot where it runs
smoothest. Is all that stuff you=99ve got lashed to
the boom tube the muffler you=99ve been telling us
about?
Whew, sometimes our best ideas an efforts just don=99t
seem
to work out. I=99ve been there before. I think that=99s
the
tallest Kolb I=99ve ever seen. I=99m on the short side
so
I=99d need a ladder just to get into the cockpit. Good
luck! George H.Firestar FS100, Hirth
270214GDH Mesick,
Michigan gdhelton@gmail.com
Sent
from my iPhone
On Jul 4, 2018, at
3:03 PM, Rick Neilsen <neilsenrm@gmail.com>
wrote:
Bill
I'm sure Larry will chime with
his HKS knowledge.
You need to get over that airplane
vs Ultralight thing. Vibrations are bad news. My
redrive VW
runs smoother at cruise RPMs than any GA airplane I
have
ever flown.
Most airplane engines have RPMs
that you stay away from or pass through quickly. The
HKS is
known for its smoothness. I have to believe that what
you
have experienced is torsional resonance. Take the prop
off
and it will likely run smooth a silk. The higher the
compression and fewer the cylinders the harder it is
to
tame. Geared engines are more prone to this issue but
some
direct drive/prop engines have issues also.
Internal
combustion engines will slow down on compression stroke
and
speed up on ignition stroke. A prop wants to turn a
constant
RPM. When a prop is subjected to these drastic changes
in
RPM (resonance) the prop blades will whip around and
do
nasty things and sometimes worse. All reduction drive
engines have some form of dampening device to reduce
this
resonance but will likely not work sufficiently at all
RPMs
(normally have more issues at idle RPMs). It is also
possible that engine/prop combination will not
work.
Worth what you paid for
it.
Rick NeilsenRedrive VW Powered
MKIIIC
On Wed, Jul
4, 2018 at 1:20 PM Bill Berle <victorbravo@sbcglobal.net>
wrote:
Greetings
Kolbers,
Yesterday we finally were able to test run the HKS
engine
installation on my Firestar 2. The HKS engine started
right
up and ran, but it needed carburetor adjustment. I had
a
friend there who has experience with the HKS engine,
and he
was kind enough to adjust the carburetors using a dual
vacuum gauge.
The one big issue I had was that the engine vibration
was
far far more than I was ever used to seeing on an
aircraft.
Part of this is that I'm "an airplane
guy"
instead of "an ultralight guy", Part of it is
that
the HKS is an opposed 2 cylinder engine with a very
high
compression ratio (11 to 1). But part of this is also
that
it did shake and vibrate a LOT, and I started thinking
about
how things tend to get loose and rattle apart in a
high
vibration environment.
The one thing that really worried me is that around
idle
speed something became resonant and the wing struts
started
to vibrate up and down in the middle, maybe half an
inch up
and hald an inch down versus a straight line. Aluminum
does
NOT like this kind of vibration! Neither do fasteners.
After
about two minutes we shut the engine down, and someone
foun
the wing strut attachment pin (the short clevis pin) on
the
ground next to the airplane. I had put the pin in place
from
above without the safety pin )ground runs only). The
vibration backed the pin completely out!
Does anyone else have this kind of wing strut vibration
with
the Kolb?
Photos of the test run and adjustment wre posted here,
scroll halfway down the page to to post # 952
http://www.homebuiltairplanes.
com/forums/showthread.php?t
28504&page=64&p=433039#
post433039
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and
for-profit
entities
==== ===== =
-List" rel="noreferrer"
target="_blank"> <http://www.matronics.com/Navig>
http://www.matronics.com/Navig
ator?Kolb-List
====
===== =
FORUMS -
eferrer"
target="_blank"> <http://forums.matronics.com/>
http://forums.matronics.com
====
===== =
WIKI -
errer"
target="_blank"> <http://wiki.matronics.com/>
http://wiki.matronics.com
====
===== =
b Site -
-Matt Dralle, List Admin.
rel="noreferrer"
target="_blank"> <http://www.matronics.com/contr>
http://www.matronics.com/contr
ibution
====
===== =
--
=9CBlessed
are the cracked, for they shall let in the light.=9D Groucho
Marx
http://www.matronics.com/Navigator?Kolb-List
http://forums.matronics.com
http://wiki.matronics.com
http://www.matronics.com/contribution
Message 6
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Firestar/HKS Engine Test Run |
Charlie:
Used track wooden props on my US and FS with bond paper shims.
Never needed to shim the WARP Drive props. They seem to be true or
within 1/16=9D when they come from the factory.
John h
Atlanta, GA
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Charlie
England
Sent: Thursday, July 5, 2018 8:13 AM
Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
I've not had a runout adjustment feature on any prop I've ever used, but
with heavier homebuilts running Lycs & Conts, the SOP is to measure
tracking, and shim between the engine's prop flange and the prop's
mating surface to get equal tracking. Often, a strip of typing paper
around the bolt circle arc on one side is enough to move the tip close
to 1/8". I don't recall your prop bran witd/model, but if you're seeing
1/2" of static runout on a prop with a machined hub and blades made in
molds, you could have either a defective prop, or a bent flange. On the
other hand, if it's just out that much while running, it could just be
balance, or unequal pitch among the blades, or slight runout made worse
by running the engine.
Static balance of the prop is a good first step, and relatively easy to
do. Dynamic balance is better if you can beg/borrow a balancer, but if
static balance and tracking are not right, the dynamic balancer may not
be able to help you.
Pusher props do see weird airflow; that's one reason fast pushers
(VariEze, etc) don't have quite the speed gains over tractor designs
that the calculations would suggest. But I've never heard of it causing
such drastic prop oscillations.
Charlie
On Thu, Jul 5, 2018 at 3:23 AM, Bill Berle <victorbravo@sbcglobal.net>
wrote:
Thank you guys again for putting your brains on this :)
A year ago I had contacted Jerry Olenik at Green Sky (RIP Jerry), and
he gave me a rough number of "something about 24 inches" between the
exhaust flange and the merge. That is what we built. I had actually sent
HKS Japan an e-mail and got no reply whatsoever (not even a rejection to
my request for info). That was disappointing, and not 100% professional
on their part.
The exhaust has a "restraining collar" bolted to the bolt that holds the
tailboom tube to the fuselage at the back of the cage. This restraint is
like a giant Adel clamp, except it has 1/8" gap around the exhaust pipe.
The concept (per my aero engineer) is to prevent the exhaust from moving
much or get into the prop, but to allow it to move a little so it can
adjust itself in the muffler due to movement and heat expansion. This
restraint is well below the flex joint, but before the pipe bends around
the tailboom towards the muffler.
I have made arrangements to borrow a prop balancer, to at least
eliminate that as the culprit. I'm also going to re-pitch the prop, at
the same time as checking the runout. As mentioned, there's no runout
adjustment on this prop, so it may be moot.
One other possibility for the runout is that as the prop blades pass
near the exhaust and the rear of the cage, there is a "dead spot" or
eddy current of air that allows that blade to see a little different
in-flow or out-flow, resulting in THAT blade making a little less or
more thrust at that instant, causing an aerodynamic fore-aft vibration
(as opposed to a mass balance problem).
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and
for-profit entities
--------------------------------------------
On Wed, 7/4/18, Richard Girard <aslsa.rng@gmail.com> wrote:
Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
To: "kolb-list@matronics.com" <kolb-list@matronics.com>
Date: Wednesday, July 4, 2018, 9:34 PM
Bill, I've been
flying in front of an HKS on my trike for 11 years. It does
not shake as you describe yours. Even when I first flew it
with the carbs significantly out of synch it was smooth. The
only shaking it does is on shutdown. Since you've
already synched the carbs it should run like a sewing
machine. Sorry I can't tell you anything more than your
engine is not running properly.I looked up the info I
got from the HKS group.
" Jim
Carruthers fabricated the exhaust system for my HKS when he
did the install on my Avid. We contacted HKS in Japan
about exhaust system requirements and received a reply back
from an HKS engineer. He said the headers need to merge at
500mm for proper scavenging and the length after the
merge was not critical though he noted that installations
with excessively long pipes after the merge had experienced
rough idling issues. As far as individual headers with no
merge, there was an HKS on a Skyraider at OshKosh years ago
that had independent headers going to super trapp mufflers.
They had a difficult time getting the engine to run well and
it was way off on power. Jim routed my exhaust tubes to
merge as close to 500mm as room would allow in the cowling
and my engine runs fantastic. Right after the merge he
rolled a simple muffler can with no baffles and its pretty
quiet."
Hope this
helps,Rick
Message 7
INDEX | Back to Main INDEX |
PREVIOUS | Skip to PREVIOUS Message |
NEXT | Skip to NEXT Message |
LIST | Reply to LIST Regarding this Message |
SENDER | Reply to SENDER Regarding this Message |
|
Subject: | Re: Firestar/HKS Engine Test Run |
I agree; there's no reason for a Warp Drive or similar design with 'made
in a mold' blades and a machined hub to have any runout, unless it's
defective, or the drive's prop flange is bent.
Charlie
On 7/5/2018 10:44 AM, John Hauck wrote:
>
> Charlie:
>
> Used track wooden props on my US and FS with bond paper shims.
>
> Never needed to shim the WARP Drive props. They seem to be true or
> within 1/16 when they come from the factory.
>
> John h
>
> Atlanta, GA
>
> *From:*owner-kolb-list-server@matronics.com
> [mailto:owner-kolb-list-server@matronics.com] *On Behalf Of *Charlie
> England
> *Sent:* Thursday, July 5, 2018 8:13 AM
> *To:* kolb-list@matronics.com
> *Subject:* Re: Kolb-List: Firestar/HKS Engine Test Run
>
> I've not had a runout adjustment feature on any prop I've ever used,
> but with heavier homebuilts running Lycs & Conts, the SOP is to
> measure tracking, and shim between the engine's prop flange and the
> prop's mating surface to get equal tracking. Often, a strip of typing
> paper around the bolt circle arc on one side is enough to move the tip
> close to 1/8". I don't recall your prop branwitd/model, but if you're
> seeing 1/2" of static runout on a prop with a machined hub and blades
> made in molds, you could have either a defective prop, or a bent
> flange. On the other hand, if it's just out that much while running,
> it could just be balance, or unequal pitch among the blades, or slight
> runout made worse by running the engine.
>
> Static balance of the prop is a good first step, and relatively easy
> to do. Dynamic balance is better if you can beg/borrow a balancer, but
> if static balance and tracking are not right, the dynamic balancer may
> not be able to help you.
>
> Pusher props do see weird airflow; that's one reason fast pushers
> (VariEze, etc) don't have quite the speed gains over tractor designs
> that the calculations would suggest. But I've never heard of it
> causing such drastic prop oscillations.
>
> Charlie
>
> On Thu, Jul 5, 2018 at 3:23 AM, Bill Berle <victorbravo@sbcglobal.net
> <mailto:victorbravo@sbcglobal.net>> wrote:
>
> <mailto:victorbravo@sbcglobal.net>>
>
> Thank you guys again for putting your brains on this :)
>
> A year ago I had contacted Jerry Olenik at Green Sky (RIP Jerry), and
> he gave me a rough number of "something about 24 inches" between the
> exhaust flange and the merge. That is what we built. I had actually
> sent HKS Japan an e-mail and got no reply whatsoever (not even a
> rejection to my request for info). That was disappointing, and not
> 100% professional on their part.
>
> The exhaust has a "restraining collar" bolted to the bolt that holds
> the tailboom tube to the fuselage at the back of the cage. This
> restraint is like a giant Adel clamp, except it has 1/8" gap around
> the exhaust pipe. The concept (per my aero engineer) is to prevent the
> exhaust from moving much or get into the prop, but to allow it to move
> a little so it can adjust itself in the muffler due to movement and
> heat expansion. This restraint is well below the flex joint, but
> before the pipe bends around the tailboom towards the muffler.
>
> I have made arrangements to borrow a prop balancer, to at least
> eliminate that as the culprit. I'm also going to re-pitch the prop, at
> the same time as checking the runout. As mentioned, there's no runout
> adjustment on this prop, so it may be moot.
>
> One other possibility for the runout is that as the prop blades pass
> near the exhaust and the rear of the cage, there is a "dead spot" or
> eddy current of air that allows that blade to see a little different
> in-flow or out-flow, resulting in THAT blade making a little less or
> more thrust at that instant, causing an aerodynamic fore-aft vibration
> (as opposed to a mass balance problem).
>
>
> Bill Berle
> www.ezflaphandle.com <http://www.ezflaphandle.com> - safety &
> performance upgrade for light aircraft
> www.grantstar.net <http://www.grantstar.net> - winning proposals
> for non-profit and for-profit entities
>
> --------------------------------------------
> On Wed, 7/4/18, Richard Girard <aslsa.rng@gmail.com
> <mailto:aslsa.rng@gmail.com>> wrote:
>
> Subject: Re: Kolb-List: Firestar/HKS Engine Test Run
> To: "kolb-list@matronics.com <mailto:kolb-list@matronics.com>"
> <kolb-list@matronics.com <mailto:kolb-list@matronics.com>>
> Date: Wednesday, July 4, 2018, 9:34 PM
>
> Bill, I've been
> flying in front of an HKS on my trike for 11 years. It does
> not shake as you describe yours. Even when I first flew it
> with the carbs significantly out of synch it was smooth. The
> only shaking it does is on shutdown. Since you've
> already synched the carbs it should run like a sewing
> machine. Sorry I can't tell you anything more than your
> engine is not running properly.I looked up the info I
> got from the HKS group.
> "Jim
> Carruthers fabricated the exhaust system for my HKS when he
> did the install on my Avid. We contacted HKS in Japan
> about exhaust system requirements and received a reply back
> from an HKS engineer. He said the headers need to merge at
> 500mm for proper scavenging and the length after the
> merge was not critical though he noted that installations
> with excessively long pipes after the merge had experienced
> rough idling issues. As far as individual headers with no
> merge, there was an HKS on a Skyraider at OshKosh years ago
> that had independent headers going to super trapp mufflers.
> They had a difficult time getting the engine to run well and
> it was way off on power. Jim routed my exhaust tubes to
> merge as close to 500mm as room would allow in the cowling
> and my engine runs fantastic. Right after the merge he
> rolled a simple muffler can with no baffles and its pretty
> quiet."
> Hope this
> helps,Rick
>
---
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|