Today's Message Index:
----------------------
1. 04:43 AM - N58SG Sold (Watkinsdw)
2. 04:45 AM - Re: N58SG Sold (Watkinsdw)
3. 05:53 AM - Re: Firefly/447 RPM question (west1m)
4. 07:50 AM - Re: Re: Firefly/447 RPM question (Rick Neilsen)
5. 08:06 AM - Re: Re: Firefly/447 RPM question (John Hauck)
6. 09:02 AM - Re: Re: Firefly/447 RPM question (Stuart Harner)
7. 09:13 AM - Re: Re: Firefly/447 RPM question (Herb)
8. 09:25 AM - Re: Re: Firefly/447 RPM question (Stuart Harner)
9. 10:22 AM - Re: Re: Firefly/447 RPM question (John Hauck)
10. 11:45 AM - Re: Re: Firefly/447 RPM question (Stuart Harner)
11. 12:42 PM - Re: Re: Firefly/447 RPM question (Gary Aman)
12. 07:54 PM - Re: Firefly/447 RPM question (Richard Pike)
13. 08:27 PM - Re: Re: Firefly/447 RPM question (John Hauck)
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 |
|
Hi, Gang,
After a great visit with the Kolb folks and John Hauck at S&F, I returned to Pompano,
and met with a real gentleman who flew down from Minnesota to look at my
Steven Green MK III. He bought her on the spot, after a test flight with me
at 190, him at 220 and 10 gallons of fuel. She flew great, and sweetly, as is
her style, when I'm lucky!
He has a 2005 Firestar with a recently rebuilt 503 that he will be selling. If
anyone is in the market, contact me off-list, and I'll give you his contact info.
Thanks for the community over the years. I'll still be listening in, but I'm out
of the ownership business for now.
Dave Watkins
Mark III Classic
Pompano Beach, FL
954-608-5423
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441364#441364
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 |
|
Oops, meant to say, "Landed Sweetly!"
Should have previewed before posting...
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441365#441365
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: Firefly/447 RPM question |
I just started flying my Firefly. It was running very hot 1200+ ish.
66' 30 pitch wooden prop. the prop is a bit under pitched as I can over rev it.
However, I saw a chart in Leading edge catalog that shows a 155 main jet for a
447 with a silencer or a 165 jet with out. I only have a K&N type filter.
I switched to a 162 jet and a moved the needle to the middle rich position and
problem solved, low 1000 temps. I will likely put the needle back to the middle
lean position.
--------
West1m
Hastings, MN
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441368#441368
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: | Re: Firefly/447 RPM question |
I read an article a few years back from the guy that developed the EGT
system. He said that he was against the idea that there be any number
markings on the gage. The only information that was important is that the
pilot can see quickly that the engine has been leaned too much. The result
is a much quicker swing of the EGT than the CHT when leaning in flight.
That is also how it is explained during my private pilot training.
So all this talk about adjusting the prop to get a specific EGT number just
sounds funny. I fail to understand how a engine is better when the heat of
the exhaust is captured more by the engine.
By all means get the prop loading right. Make sure the CHT temps are in
line and the spark plugs read correctly (these are the important things).
Again the EGT will tell you quickly when you have leaned the mixture too
much.
As always worth what you paid of it.
Rick Neilsen
Redrive VW Powered MKIIIC
On Mon, Apr 27, 2015 at 8:53 AM, west1m <west1m@hotmail.com> wrote:
>
> I just started flying my Firefly. It was running very hot 1200+ ish.
> 66' 30 pitch wooden prop. the prop is a bit under pitched as I can over
> rev it.
> However, I saw a chart in Leading edge catalog that shows a 155 main jet
> for a 447 with a silencer or a 165 jet with out. I only have a K&N type
> filter.
> I switched to a 162 jet and a moved the needle to the middle rich
> position and problem solved, low 1000 temps. I will likely put the needle
> back to the middle lean position.
>
> --------
> West1m
> Hastings, MN
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=441368#441368
>
>
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: | Re: Firefly/447 RPM question |
Aluminum melts at 1221F. Rotax two stroke EGT redline is 1200. That's
close to the melting point. Instruments are not precision. A tiny hot
spot will melt a speck of the piston ring groove, enough to cause rings
to stick and blow by, then seizure.
I am a fan of the four stroke. They aren't as critical to tune as the
two stroke. They run well for me right out of the box. Prop loading is
not critical.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Rick Neilsen
Sent: Monday, April 27, 2015 9:50 AM
Subject: Re: Kolb-List: Re: Firefly/447 RPM question
I read an article a few years back from the guy that developed the EGT
system. He said that he was against the idea that there be any number
markings on the gage. The only information that was important is that
the pilot can see quickly that the engine has been leaned too much. The
result is a much quicker swing of the EGT than the CHT when leaning in
flight. That is also how it is explained during my private pilot
training.
So all this talk about adjusting the prop to get a specific EGT number
just sounds funny. I fail to understand how a engine is better when the
heat of the exhaust is captured more by the engine.
By all means get the prop loading right. Make sure the CHT temps are in
line and the spark plugs read correctly (these are the important
things). Again the EGT will tell you quickly when you have leaned the
mixture too much.
As always worth what you paid of it.
Rick Neilsen
Redrive VW Powered MKIIIC
On Mon, Apr 27, 2015 at 8:53 AM, west1m <west1m@hotmail.com> wrote:
I just started flying my Firefly. It was running very hot 1200+ ish.
66' 30 pitch wooden prop. the prop is a bit under pitched as I can over
rev it.
However, I saw a chart in Leading edge catalog that shows a 155 main
jet for a 447 with a silencer or a 165 jet with out. I only have a K&N
type filter.
I switched to a 162 jet and a moved the needle to the middle rich
position and problem solved, low 1000 temps. I will likely put the
needle back to the middle lean position.
--------
West1m
Hastings, MN
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441368#441368
-List" target="_blank">http://www.matronics.com/Navigator?Kolb-List
FORUMS -
_blank">http://forums.matronics.com
b Site -
-Matt Dralle, List Admin.
target="_blank">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: | Re: Firefly/447 RPM question |
Not knowing a great deal about 2 stroke engines, I think the EGT limits
are to keep the exhaust ports from burning out. EGT is an indication of
whether or not the combustion is taking place mostly in the cylinder or
if it is spilling out into the exhaust. A charge of gas that is still
burning when the piston goes past the exhaust port would kind of act
like a cutting torch on the edges of the port.
On my 447 the only leaning is done with the clip on the needle (or
swapping needles and or jets). You can make the mixture more rich by
adding =9Cchoke=9D, which is what I have done on a couple of
occasions. Of course, the ideal is to get the engine to operate
properly though the entire RPM range so you don=99t have to fiddle
with things like the enricher while in the landing circuit.
I don=99t have anything against using the enricher when needed,
and indeed that may be the best solution for me. Maybe it will become
part of my descent and landing procedure. Kind of like adding carb heat
and going full rich when flying my old Cherokee. If that becomes the
case, I may relocate the enricher lever to be down by the throttle so I
am not reaching around blindly for a lever I can=99t see.
>From what I can gather, prop loading/engine mixtures is more sensitive
on little two strokes like the 447 and changes quite readily with temp
and altitude. Trying to fly in 3 seasons may cause me to have to adjust
things several times a year.
In any case, weather forecast is for flying conditions tomorrow.
Hopefully they are right this time, I am anxious to get back up and do
some more experimenting.
Stuart
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Rick Neilsen
Sent: Monday, April 27, 2015 9:50 AM
Subject: Re: Kolb-List: Re: Firefly/447 RPM question
I read an article a few years back from the guy that developed the EGT
system. He said that he was against the idea that there be any number
markings on the gage. The only information that was important is that
the pilot can see quickly that the engine has been leaned too much. The
result is a much quicker swing of the EGT than the CHT when leaning in
flight. That is also how it is explained during my private pilot
training.
So all this talk about adjusting the prop to get a specific EGT number
just sounds funny. I fail to understand how a engine is better when the
heat of the exhaust is captured more by the engine.
By all means get the prop loading right. Make sure the CHT temps are in
line and the spark plugs read correctly (these are the important
things). Again the EGT will tell you quickly when you have leaned the
mixture too much.
As always worth what you paid of it.
Rick Neilsen
Redrive VW Powered MKIIIC
On Mon, Apr 27, 2015 at 8:53 AM, west1m <west1m@hotmail.com> wrote:
I just started flying my Firefly. It was running very hot 1200+ ish.
66' 30 pitch wooden prop. the prop is a bit under pitched as I can over
rev it.
However, I saw a chart in Leading edge catalog that shows a 155 main
jet for a 447 with a silencer or a 165 jet with out. I only have a K&N
type filter.
I switched to a 162 jet and a moved the needle to the middle rich
position and problem solved, low 1000 temps. I will likely put the
needle back to the middle lean position.
--------
West1m
Hastings, MN
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441368#441368
-List" target="_blank">http://www.matronics.com/Navigator?Kolb-List
FORUMS -
_blank">http://forums.matronics.com
b Site -
-Matt Dralle, List Admin.
target="_blank">http://www.matronics.com/contribution
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: Firefly/447 RPM question |
remember also...Stuart...the engine is on the main jet from somewhere
beyond 65 to 75 % throttle opening...before that you are on the needle
jet and needle..... Herb
On 04/27/2015 11:02 AM, Stuart Harner wrote:
>
> Not knowing a great deal about 2 stroke engines, I think the EGT
> limits are to keep the exhaust ports from burning out. EGT is an
> indication of whether or not the combustion is taking place mostly in
> the cylinder or if it is spilling out into the exhaust. A charge of
> gas that is still burning when the piston goes past the exhaust port
> would kind of act like a cutting torch on the edges of the port.
>
> On my 447 the only leaning is done with the clip on the needle (or
> swapping needles and or jets). You can make the mixture more rich by
> adding choke, which is what I have done on a couple of occasions.
> Of course, the ideal is to get the engine to operate properly though
> the entire RPM range so you dont have to fiddle with things like the
> enricher while in the landing circuit.
>
> I dont have anything against using the enricher when needed, and
> indeed that may be the best solution for me. Maybe it will become
> part of my descent and landing procedure. Kind of like adding carb
> heat and going full rich when flying my old Cherokee. If that becomes
> the case, I may relocate the enricher lever to be down by the throttle
> so I am not reaching around blindly for a lever I cant see.
>
> From what I can gather, prop loading/engine mixtures is more sensitive
> on little two strokes like the 447 and changes quite readily with temp
> and altitude. Trying to fly in 3 seasons may cause me to have to
> adjust things several times a year.
>
> In any case, weather forecast is for flying conditions tomorrow.
> Hopefully they are right this time, I am anxious to get back up and do
> some more experimenting.
>
> Stuart
>
> *From:*owner-kolb-list-server@matronics.com
> [mailto:owner-kolb-list-server@matronics.com] *On Behalf Of *Rick Neilsen
> *Sent:* Monday, April 27, 2015 9:50 AM
> *To:* kolb-list@matronics.com
> *Subject:* Re: Kolb-List: Re: Firefly/447 RPM question
>
> I read an article a few years back from the guy that developed the EGT
> system. He said that he was against the idea that there be any number
> markings on the gage. The only information that was important is that
> the pilot can see quickly that the engine has been leaned too much.
> The result is a much quicker swing of the EGT than the CHT when
> leaning in flight. That is also how it is explained during my private
> pilot training.
>
> So all this talk about adjusting the prop to get a specific EGT number
> just sounds funny. I fail to understand how a engine is better when
> the heat of the exhaust is captured more by the engine.
>
> By all means get the prop loading right. Make sure the CHT temps are
> in line and the spark plugs read correctly (these are the important
> things). Again the EGT will tell you quickly when you have leaned the
> mixture too much.
>
> As always worth what you paid of it.
>
> Rick Neilsen
>
> Redrive VW Powered MKIIIC
>
> On Mon, Apr 27, 2015 at 8:53 AM, west1m <west1m@hotmail.com
> <mailto:west1m@hotmail.com>> wrote:
>
> <mailto:west1m@hotmail.com>>
>
> I just started flying my Firefly. It was running very hot 1200+ ish.
> 66' 30 pitch wooden prop. the prop is a bit under pitched as I can
> over rev it.
> However, I saw a chart in Leading edge catalog that shows a 155 main
> jet for a 447 with a silencer or a 165 jet with out. I only have a K&N
> type filter.
> I switched to a 162 jet and a moved the needle to the middle rich
> position and problem solved, low 1000 temps. I will likely put the
> needle back to the middle lean position.
>
> --------
> West1m
> Hastings, MN
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=441368#441368
>
>
> ==========
> -List" target="_blank">http://www.matronics.com/Navigator?Kolb-List
> ==========
> FORUMS -
> _blank">http://forums.matronics.com
> ==========
> b Site -
> -Matt Dralle, List Admin.
> target="_blank">http://www.matronics.com/contribution
> ==========
>
>
> * *
> * *
> **
> **
> **
> **
> **
> *http://www.matronics.com/Navigator?Kolb-List*
> **
> **
> *http://forums.matronics.com*
> **
> **
> **
> **
> *http://www.matronics.com/contribution*
> **
> * *
> *
>
>
> *
Message 8
| 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: Firefly/447 RPM question |
Absolutely. I am shooting for high 1100=99s EGT and mid
300=99s for CHT. I think the 2 stroke is a fine line dance between
shock cooling and burning up. Carefully monitored and well maintained
the little Rotax would seem to be capable of going beyond what the
factory says it will, but make any mistakes and you are looking for a
place to land!
The Rotax guy from LEAF told us at OSH that 1250=C2=B0 was the absolute
top red line limit. Since my manual has no listing for max EGT, I will
defer to the factory certified guy. Consequently, I have my EIS limit
set to 1225=C2=B0.
If I could find a viable 4 stroke to put on a Firefly and keep it Part
103, I would buy it in a heartbeat.
Of course, 2 HP from every cubic inch of displacement on .01 GPH is
every pilots wet dream, right? Now where did I leave that box of
di-lithium crystals and that bottle of anti-matter?
Anyway, I think there may be a future in electric motors for the
Firefly. They are getting close to having reliable long lasing
batteries. The motors and controllers already exist. If you can get a
battery that will run a 30 HP motor for an hour with some left in
reserve that does not cost $45K and weigh 100#, we will be in business.
Stuart
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of John Hauck
Sent: Monday, April 27, 2015 10:06 AM
Subject: RE: Kolb-List: Re: Firefly/447 RPM question
Aluminum melts at 1221F. Rotax two stroke EGT redline is 1200. That's
close to the melting point. Instruments are not precision. A tiny hot
spot will melt a speck of the piston ring groove, enough to cause rings
to stick and blow by, then seizure.
I am a fan of the four stroke. They aren't as critical to tune as the
two stroke. They run well for me right out of the box. Prop loading is
not critical.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Rick Neilsen
Sent: Monday, April 27, 2015 9:50 AM
Subject: Re: Kolb-List: Re: Firefly/447 RPM question
I read an article a few years back from the guy that developed the EGT
system. He said that he was against the idea that there be any number
markings on the gage. The only information that was important is that
the pilot can see quickly that the engine has been leaned too much. The
result is a much quicker swing of the EGT than the CHT when leaning in
flight. That is also how it is explained during my private pilot
training.
So all this talk about adjusting the prop to get a specific EGT number
just sounds funny. I fail to understand how a engine is better when the
heat of the exhaust is captured more by the engine.
By all means get the prop loading right. Make sure the CHT temps are in
line and the spark plugs read correctly (these are the important
things). Again the EGT will tell you quickly when you have leaned the
mixture too much.
As always worth what you paid of it.
Rick Neilsen
Redrive VW Powered MKIIIC
On Mon, Apr 27, 2015 at 8:53 AM, west1m <west1m@hotmail.com> wrote:
I just started flying my Firefly. It was running very hot 1200+ ish.
66' 30 pitch wooden prop. the prop is a bit under pitched as I can over
rev it.
However, I saw a chart in Leading edge catalog that shows a 155 main
jet for a 447 with a silencer or a 165 jet with out. I only have a K&N
type filter.
I switched to a 162 jet and a moved the needle to the middle rich
position and problem solved, low 1000 temps. I will likely put the
needle back to the middle lean position.
--------
West1m
Hastings, MN
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441368#441368
-List" target="_blank">http://www.matronics.com/Navigator?Kolb-List
FORUMS -
_blank">http://forums.matronics.com
b Site -
-Matt Dralle, List Admin.
target="_blank">http://www.matronics.com/contribution
- The Kolb-List Email Forum -
--> http://www.matronics.com/Navigator?Kolb-List
- MATRONICS WEB FORUMS -
--> http://forums.matronics.com
- List Contribution Web Site -
Thank you for your generous support!
-Matt Dralle, List Admin.
--> http://www.matronics.com/contribution
Message 9
| 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: Firefly/447 RPM question |
I don't seem to be able to copy the page out of the two stroke manual,
but MAX EGT is 1200F. Normal EGT is 860F to 1000F. That is on page
10-1.
MAX CHT is 500F. Normal is 374-446F.
Seems to me if you operate the 447 at 1200F and have your warning light
set at 1225F, you will be well over the red line before you know it. I
cannot remember how far downstream the EGT probe is located, but it is a
significant distance from the edge of the exhaust port. Seems to me, as
an uneducated hobbyist, the exhaust will be cooler at the probe.
Again, ultralight instruments are far from precision instruments.
I did pretty good with my two stroke engines flying them as they were
set up at the factory. The idea is to prop to the engine, not tune the
engine to the prop. Most two stroke engine failures are the result of
operators chasing their tail, trying to reinvent the wheel.
Here's the URL for the Rotax Two Stroke Manual. I assume it is the
current version:
http://www.rotax-aircraft-engines.com/portaldata/5/dokus/d04495.pdf
The above is my opinion only.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Stuart Harner
Sent: Monday, April 27, 2015 11:24 AM
Subject: RE: Kolb-List: Re: Firefly/447 RPM question
Absolutely. I am shooting for high 1100=99s EGT and mid
300=99s for CHT. I think the 2 stroke is a fine line dance between
shock cooling and burning up. Carefully monitored and well maintained
the little Rotax would seem to be capable of going beyond what the
factory says it will, but make any mistakes and you are looking for a
place to land!
The Rotax guy from LEAF told us at OSH that 1250=C2=B0 was the absolute
top red line limit. Since my manual has no listing for max EGT, I will
defer to the factory certified guy. Consequently, I have my EIS limit
set to 1225=C2=B0.
If I could find a viable 4 stroke to put on a Firefly and keep it Part
103, I would buy it in a heartbeat.
Of course, 2 HP from every cubic inch of displacement on .01 GPH is
every pilots wet dream, right? Now where did I leave that box of
di-lithium crystals and that bottle of anti-matter?
Anyway, I think there may be a future in electric motors for the
Firefly. They are getting close to having reliable long lasing
batteries. The motors and controllers already exist. If you can get a
battery that will run a 30 HP motor for an hour with some left in
reserve that does not cost $45K and weigh 100#, we will be in business.
Stuart
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of John Hauck
Sent: Monday, April 27, 2015 10:06 AM
Subject: RE: Kolb-List: Re: Firefly/447 RPM question
Aluminum melts at 1221F. Rotax two stroke EGT redline is 1200. That's
close to the melting point. Instruments are not precision. A tiny hot
spot will melt a speck of the piston ring groove, enough to cause rings
to stick and blow by, then seizure.
I am a fan of the four stroke. They aren't as critical to tune as the
two stroke. They run well for me right out of the box. Prop loading is
not critical.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Rick Neilsen
Sent: Monday, April 27, 2015 9:50 AM
Subject: Re: Kolb-List: Re: Firefly/447 RPM question
I read an article a few years back from the guy that developed the EGT
system. He said that he was against the idea that there be any number
markings on the gage. The only information that was important is that
the pilot can see quickly that the engine has been leaned too much. The
result is a much quicker swing of the EGT than the CHT when leaning in
flight. That is also how it is explained during my private pilot
training.
So all this talk about adjusting the prop to get a specific EGT number
just sounds funny. I fail to understand how a engine is better when the
heat of the exhaust is captured more by the engine.
By all means get the prop loading right. Make sure the CHT temps are in
line and the spark plugs read correctly (these are the important
things). Again the EGT will tell you quickly when you have leaned the
mixture too much.
As always worth what you paid of it.
Rick Neilsen
Redrive VW Powered MKIIIC
On Mon, Apr 27, 2015 at 8:53 AM, west1m <west1m@hotmail.com> wrote:
I just started flying my Firefly. It was running very hot 1200+ ish.
66' 30 pitch wooden prop. the prop is a bit under pitched as I can over
rev it.
However, I saw a chart in Leading edge catalog that shows a 155 main
jet for a 447 with a silencer or a 165 jet with out. I only have a K&N
type filter.
I switched to a 162 jet and a moved the needle to the middle rich
position and problem solved, low 1000 temps. I will likely put the
needle back to the middle lean position.
--------
West1m
Hastings, MN
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441368#441368
-List" target="_blank">http://www.matronics.com/Navigator?Kolb-List
FORUMS -
_blank">http://forums.matronics.com
b Site -
-Matt Dralle, List Admin.
target="_blank">http://www.matronics.com/contribution
- The Kolb-List Email Forum -
--> http://www.matronics.com/Navigator?Kolb-List
- MATRONICS WEB FORUMS -
--> http://forums.matronics.com
- List Contribution Web Site -
Thank you for your generous support!
-Matt Dralle, List Admin.
--> http://www.matronics.com/contribution
http://www.matronics.com/Navigator?Kolb-List
http://forums.matronics.com
http://www.matronics.com/contribution
Message 10
| 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: Firefly/447 RPM question |
Ah-Ha! Good find John. Thanks for the link.
My manual is older, and has this info:
I will be downloading and using the new version from here on out. EIS
limits will be adjusted down to 1200=C2=B0. It is also interesting to
see that it is acceptable to be in the high 800=99s in normal
operation. My understanding was that it should be at least 1000=C2=B0.
Strange, I had asked this question at OSH specifically since it was not
in my manual. Based on the higher CHT temps, the slightly higher
1250=C2=B0 EGT seemed to be in line that the 447 ran slightly hotter
than the 503. HMM, makes me wonder about other things said
there
Most of the time I am seeing 1150 =93 1190, but on a couple of
occasions I have seen it spike into the 1200+ range, which I quickly got
out of by changing throttle settings or adding =9Cchoke=9D.
While I don=99t think any damage was done, there certainly is no
reason to push destructive temperatures.
The probe bosses were welded in by Rotax. I don=99t remember the
dimensions off the top of my head, but I did measure to see that they
matched the instructions of where to drill if there were no bosses.
If memory serves me the hot spot may well be farther downstream than the
port opening itself. From welding class days the hot spot of the flame
is not at the tip but at the point of the lighter blue flame in the
middle. Since I can=99t see inside the exhaust, I can only imagine
that this MAY be the case.
I am going to read this updated version to see what other changes there
were. That may shed more light on what steps to take next.
The learning curve never ends.
Thanks,
Stuart
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of John Hauck
Sent: Monday, April 27, 2015 12:22 PM
Subject: RE: Kolb-List: Re: Firefly/447 RPM question
I don't seem to be able to copy the page out of the two stroke manual,
but MAX EGT is 1200F. Normal EGT is 860F to 1000F. That is on page
10-1.
MAX CHT is 500F. Normal is 374-446F.
Seems to me if you operate the 447 at 1200F and have your warning light
set at 1225F, you will be well over the red line before you know it. I
cannot remember how far downstream the EGT probe is located, but it is a
significant distance from the edge of the exhaust port. Seems to me, as
an uneducated hobbyist, the exhaust will be cooler at the probe.
Again, ultralight instruments are far from precision instruments.
I did pretty good with my two stroke engines flying them as they were
set up at the factory. The idea is to prop to the engine, not tune the
engine to the prop. Most two stroke engine failures are the result of
operators chasing their tail, trying to reinvent the wheel.
Here's the URL for the Rotax Two Stroke Manual. I assume it is the
current version:
http://www.rotax-aircraft-engines.com/portaldata/5/dokus/d04495.pdf
The above is my opinion only.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Stuart Harner
Sent: Monday, April 27, 2015 11:24 AM
Subject: RE: Kolb-List: Re: Firefly/447 RPM question
Absolutely. I am shooting for high 1100=99s EGT and mid
300=99s for CHT. I think the 2 stroke is a fine line dance between
shock cooling and burning up. Carefully monitored and well maintained
the little Rotax would seem to be capable of going beyond what the
factory says it will, but make any mistakes and you are looking for a
place to land!
The Rotax guy from LEAF told us at OSH that 1250=C2=B0 was the absolute
top red line limit. Since my manual has no listing for max EGT, I will
defer to the factory certified guy. Consequently, I have my EIS limit
set to 1225=C2=B0.
If I could find a viable 4 stroke to put on a Firefly and keep it Part
103, I would buy it in a heartbeat.
Of course, 2 HP from every cubic inch of displacement on .01 GPH is
every pilots wet dream, right? Now where did I leave that box of
di-lithium crystals and that bottle of anti-matter?
Anyway, I think there may be a future in electric motors for the
Firefly. They are getting close to having reliable long lasing
batteries. The motors and controllers already exist. If you can get a
battery that will run a 30 HP motor for an hour with some left in
reserve that does not cost $45K and weigh 100#, we will be in business.
Stuart
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of John Hauck
Sent: Monday, April 27, 2015 10:06 AM
Subject: RE: Kolb-List: Re: Firefly/447 RPM question
Aluminum melts at 1221F. Rotax two stroke EGT redline is 1200. That's
close to the melting point. Instruments are not precision. A tiny hot
spot will melt a speck of the piston ring groove, enough to cause rings
to stick and blow by, then seizure.
I am a fan of the four stroke. They aren't as critical to tune as the
two stroke. They run well for me right out of the box. Prop loading is
not critical.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Rick Neilsen
Sent: Monday, April 27, 2015 9:50 AM
Subject: Re: Kolb-List: Re: Firefly/447 RPM question
I read an article a few years back from the guy that developed the EGT
system. He said that he was against the idea that there be any number
markings on the gage. The only information that was important is that
the pilot can see quickly that the engine has been leaned too much. The
result is a much quicker swing of the EGT than the CHT when leaning in
flight. That is also how it is explained during my private pilot
training.
So all this talk about adjusting the prop to get a specific EGT number
just sounds funny. I fail to understand how a engine is better when the
heat of the exhaust is captured more by the engine.
By all means get the prop loading right. Make sure the CHT temps are in
line and the spark plugs read correctly (these are the important
things). Again the EGT will tell you quickly when you have leaned the
mixture too much.
As always worth what you paid of it.
Rick Neilsen
Redrive VW Powered MKIIIC
On Mon, Apr 27, 2015 at 8:53 AM, west1m <west1m@hotmail.com> wrote:
I just started flying my Firefly. It was running very hot 1200+ ish.
66' 30 pitch wooden prop. the prop is a bit under pitched as I can over
rev it.
However, I saw a chart in Leading edge catalog that shows a 155 main
jet for a 447 with a silencer or a 165 jet with out. I only have a K&N
type filter.
I switched to a 162 jet and a moved the needle to the middle rich
position and problem solved, low 1000 temps. I will likely put the
needle back to the middle lean position.
--------
West1m
Hastings, MN
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441368#441368
-List" target="_blank">http://www.matronics.com/Navigator?Kolb-List
FORUMS -
_blank">http://forums.matronics.com
b Site -
-Matt Dralle, List Admin.
target="_blank">http://www.matronics.com/contribution
- The Kolb-List Email Forum -
--> http://www.matronics.com/Navigator?Kolb-List
- MATRONICS WEB FORUMS -
--> http://forums.matronics.com
- List Contribution Web Site -
Thank you for your generous support!
-Matt Dralle, List Admin.
--> http://www.matronics.com/contribution
http://www.matronics.com/Navigator?Kolb-List
http://forums.matronics.com
http://www.matronics.com/contribution
- The Kolb-List Email Forum -
--> http://www.matronics.com/Navigator?Kolb-List
- MATRONICS WEB FORUMS -
--> http://forums.matronics.com
- List Contribution Web Site -
Thank you for your generous support!
-Matt Dralle, List Admin.
--> http://www.matronics.com/contribution
Message 11
| 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: Firefly/447 RPM question |
Rick,
I agree with you on 4 stroke engines.But I always considered cht , on a 2 stroke
to be a indication more of load than mixture.If i was under propped it was like
running in second gear, lots of revs but not much load.no load makes the 2
stroke lean out which ups the egt but keeps the head cooler.In my opinion,you
need to prop the engine for the operating rpm then adjust the mixture for the
amount of load at that rpm.My 503 ,prop set for 6100, on takeoff gave about 1000
degrees at full throttle climb out and less than 1200 at 5500 cruise.But the
firestar was so clean the throttle was around half open at that rpm.At 5700
the egts got close to 1200 and 75 mph cruise but the head temps were always well
under the limits
G.Aman 750 hrs on the Firestar 503 dcdi oil injected
-----Original Message-----
From: Rick Neilsen <neilsenrm@gmail.com>
Sent: Mon, Apr 27, 2015 10:50 am
Subject: Re: Kolb-List: Re: Firefly/447 RPM question
I read an article a few years back from the guy that developed the EGT system.
He said that he was against the idea that there be any number markings on the
gage. The only information that was important is that the pilot can see quickly
that the engine has been leaned too much. The result is a much quicker swing
of the EGT than the CHT when leaning in flight. That is also how it is explained
during my private pilot training.
So all this talk about adjusting the prop to get a specific EGT number just sounds
funny. I fail to understand how a engine is better when the heat of the exhaust
is captured more by the engine.
By all means get the prop loading right. Make sure the CHT temps are in line and
the spark plugs read correctly (these are the important things). Again the EGT
will tell you quickly when you have leaned the mixture too much.
As always worth what you paid of it.
Rick Neilsen
Redrive VW Powered MKIIIC
On Mon, Apr 27, 2015 at 8:53 AM, west1m <west1m@hotmail.com> wrote:
I just started flying my Firefly. It was running very hot 1200+ ish.
66' 30 pitch wooden prop. the prop is a bit under pitched as I can over rev it.
However, I saw a chart in Leading edge catalog that shows a 155 main jet for
a 447 with a silencer or a 165 jet with out. I only have a K&N type filter.
I switched to a 162 jet and a moved the needle to the middle rich position and
problem solved, low 1000 temps. I will likely put the needle back to the middle
lean position.
--------
West1m
Hastings, MN
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441368#441368
===========
-List" target="_blank">http://www.matronics.com/Navigator?Kolb-List
===========
FORUMS -
_blank">http://forums.matronics.com
===========
b Site -
-Matt Dralle, List Admin.
target="_blank">http://www.matronics.com/contribution
===========
Message 12
| 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: Firefly/447 RPM question |
[quote="John Hauck"]
The idea is to prop to the engine, not tune the engine to the prop. Most two stroke
engine failures are the result of operators chasing their tail, trying to
reinvent the wheel.
john h
mkIII
Titus, Alabama
[quote]
This. Jet it the way the book says, and then fiddle with the prop pitch until the
numbers are happy. Did a 150 hour carbon cleanout of the 582 top end last week,
flew Friday, climbout turning 6300, EGT 1,000. Cruising at 5,300 to 5,600
rpm gave consistent matching EGT's of 1050 to 1100. No problem with high EGT's
on descent because you adjust the throttle a bit and they stay around 1000.
Checked the plugs after landing, they are a medium brown.
Hope to fly again tomorrow with a passenger, will give an update and maybe a photo
of the plugs. The plugs verify if the temperatures are acceptable, and if
the EGT is close to accurate. From then on, the EGT gauge is mostly to warn you
anomalies.
--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
There are two kinds of people: those who say to God, 'Thy will be done,' and those
to whom God says, 'All right, then, have it your way.'
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441420#441420
Message 13
| 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: Firefly/447 RPM question |
Shouldn't the plug check be done at the power setting that you want to
check, e.g., cruise, WOT, etc?
If the plugs are checked after landing and taxi back to the hanger, does
that not give you an indication for low speed, low power settings?
john h
mkIII
Titus, Alabama
-----Original Message-----
From: owner-kolb-list-server@matronics.com
[mailto:owner-kolb-list-server@matronics.com] On Behalf Of Richard Pike
Sent: Monday, April 27, 2015 9:54 PM
Subject: Kolb-List: Re: Firefly/447 RPM question
--> <thegreybaron@charter.net>
[quote="John Hauck"]
The idea is to prop to the engine, not tune the engine to the prop. Most
two stroke engine failures are the result of operators chasing their tail,
trying to reinvent the wheel.
john h
mkIII
Titus, Alabama
[quote]
This. Jet it the way the book says, and then fiddle with the prop pitch
until the numbers are happy. Did a 150 hour carbon cleanout of the 582 top
end last week, flew Friday, climbout turning 6300, EGT 1,000. Cruising at
5,300 to 5,600 rpm gave consistent matching EGT's of 1050 to 1100. No
problem with high EGT's on descent because you adjust the throttle a bit and
they stay around 1000. Checked the plugs after landing, they are a medium
brown.
Hope to fly again tomorrow with a passenger, will give an update and maybe a
photo of the plugs. The plugs verify if the temperatures are acceptable, and
if the EGT is close to accurate. From then on, the EGT gauge is mostly to
warn you anomalies.
--------
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
There are two kinds of people: those who say to God, 'Thy will be done,' and
those to whom God says, 'All right, then, have it your way.'
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=441420#441420
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! --
|