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		| jaydub 
 
 
 Joined: 07 Jan 2020
 Posts: 74
 
 
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				|  Posted: Wed Jul 12, 2023 2:31 pm    Post subject: prop recommendations for 447 on firestar or firefly |   |  
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				| I have a 68" Ivoprop ground adjustable that came with my 447 (both used)for my Firestar. Does anyone know what the recommended prop diameter/pitch is for the 447 powered firestar or firefly? I have flown with Ivoprops in the past and never cared for them (it seems the flex/coning gives them a lot of "slip" making them very inefficient, but I could be wrong). Every ultralight in the 90's I flew with an ivo burned a lot more fuel than the fixed 60x38 or 60x40 wood props and took longer in takeoff  as well as cruised slower (my own observations but that was all with CGS Hawks flying 447s and not Kolbs). Since wood props are just as or more expensive these days as to a composite, I'm wondering what the wisdom is these days for a prop? What wood prop came with the 447 firestars or fireflies of yore? What are the recommended composite props these days?
 I had an unmarked (brand) 60x40 wood prop that gave me 60 mph cruise in a Hawk burning 1.5 gallons an hour consistently. Before that I had a 60x38 Culver (made in PA) that burned closer to 1.8 gal/hr cruising at 60. I still have the 60x40 but long story short, it's split from hitting a green jolly rancher candy and that ruined it so it hangs on my living room wall. I wish I knew the brand as I'd buy one in a heartbeat but my guess it was a Tennessee prop.
 
 Thanks,
 Jay
 
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		| stuart(at)harnerfarm.net Guest
 
 
 
 
 
 
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				|  Posted: Wed Jul 12, 2023 3:20 pm    Post subject: prop recommendations for 447 on firestar or firefly |   |  
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				| My Firefly has a 60" 3 blade Warp Drive on the 447 with a 2.58:1 "B" box.
 Smooth, quiet and powerful, but I don't get much better than 4 G/Hr.
 4800 to 5000 engine RPM will push the Firefly ~65 MPH.
 
 The 3 blade makes it fit in the camper/hangar nicely.
 On 7/12/23 17:31, Jay Dub wrote:
 
  	  | Quote: |  	  | 
 I have a 68" Ivoprop ground adjustable that came with my 447 (both used)for my Firestar. Does anyone know what the recommended prop diameter/pitch is for the 447 powered firestar or firefly? I have flown with Ivoprops in the past and never cared for them (it seems the flex/coning gives them a lot of "slip" making them very inefficient, but I could be wrong). Every ultralight in the 90's I flew with an ivo burned a lot more fuel than the fixed 60x38 or 60x40 wood props and took longer in takeoff  as well as cruised slower (my own observations but that was all with CGS Hawks flying 447s and not Kolbs). Since wood props are just as or more expensive these days as to a composite, I'm wondering what the wisdom is these days for a prop? What wood prop came with the 447 firestars or fireflies of yore? What are the recommended composite props these days?
 
 I had an unmarked (brand) 60x40 wood prop that gave me 60 mph cruise in a Hawk burning 1.5 gallons an hour consistently. Before that I had a 60x38 Culver (made in PA) that burned closer to 1.8 gal/hr cruising at 60. I still have the 60x40 but long story short, it's split from hitting a green jolly rancher candy and that ruined it so it hangs on my living room wall. I wish I knew the brand as I'd buy one in a heartbeat but my guess it was a Tennessee prop.
 
 Thanks,
 Jay
 
 
 
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		| lcottrell 
 
  
 Joined: 29 May 2006
 Posts: 1494
 Location: Jordan Valley, Or
 
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				|  Posted: Wed Jul 12, 2023 3:41 pm    Post subject: prop recommendations for 447 on firestar or firefly |   |  
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				| It's been a while since I used a 447, but the rule of thumb was to
maintain at least an inch of clearance between the end and the tail
 boom. I used a warp drive after my wooden prop and an IVO. They are
 indestructible, and a great prop.
 
 Since the hangar is just outside my door, I decided to measure it. The
 prop is tip to tip- 66 inches with a 2 1/2 extender. This prop has
 been on a 447, a 503 and now on a HKS. John Hauck recommended it to
 me, and I concur that it is a great prop.
 Larry
 
 On Wed, Jul 12, 2023 at 4:34 PM Jay Dub <bearhawk(at)gmx.com> wrote:
 
  	  | Quote: |  	  | 
 
 I have a 68" Ivoprop ground adjustable that came with my 447 (both used)for my Firestar. Does anyone know what the recommended prop diameter/pitch is for the 447 powered firestar or firefly? I have flown with Ivoprops in the past and never cared for them (it seems the flex/coning gives them a lot of "slip" making them very inefficient, but I could be wrong). Every ultralight in the 90's I flew with an ivo burned a lot more fuel than the fixed 60x38 or 60x40 wood props and took longer in takeoff  as well as cruised slower (my own observations but that was all with CGS Hawks flying 447s and not Kolbs). Since wood props are just as or more expensive these days as to a composite, I'm wondering what the wisdom is these days for a prop? What wood prop came with the 447 firestars or fireflies of yore? What are the recommended composite props these days?
 
 I had an unmarked (brand) 60x40 wood prop that gave me 60 mph cruise in a Hawk burning 1.5 gallons an hour consistently. Before that I had a 60x38 Culver (made in PA) that burned closer to 1.8 gal/hr cruising at 60. I still have the 60x40 but long story short, it's split from hitting a green jolly rancher candy and that ruined it so it hangs on my living room wall. I wish I knew the brand as I'd buy one in a heartbeat but my guess it was a Tennessee prop.
 
 Thanks,
 Jay
 
 
 
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 --
 The older I get, the less tolerant I am of those who are intolerant of others.
 
 If you forward this email, or any part of it, please remove my email
 address before sending.
 
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		| gdhelton(at)gmail.com Guest
 
 
 
 
 
 
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				|  Posted: Wed Jul 12, 2023 3:41 pm    Post subject: prop recommendations for 447 on firestar or firefly |   |  
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				| Sent from my iPhone
 
  	  | Quote: |  	  | On Jul 12, 2023, at 7:30 PM, Stuart Harner <stuart(at)harnerfarm.net> wrote: 
 
 
 My Firefly has a 60" 3 blade Warp Drive on the 447 with a 2.58:1 "B" box.
 
 Smooth, quiet and powerful, but I don't get much better than 4 G/Hr. 4800 to 5000 engine RPM will push the Firefly ~65 MPH.
 
 The 3 blade makes it fit in the camper/hangar nicely.
 
 
 > On 7/12/23 17:31, Jay Dub wrote:
 >
 >
 > I have a 68" Ivoprop ground adjustable that came with my 447 (both used)for my Firestar. Does anyone know what the recommended prop diameter/pitch is for the 447 powered firestar or firefly? I have flown with Ivoprops in the past and never cared for them (it seems the flex/coning gives them a lot of "slip" making them very inefficient, but I could be wrong). Every ultralight in the 90's I flew with an ivo burned a lot more fuel than the fixed 60x38 or 60x40 wood props and took longer in takeoff  as well as cruised slower (my own observations but that was all with CGS Hawks flying 447s and not Kolbs). Since wood props are just as or more expensive these days as to a composite, I'm wondering what the wisdom is these days for a prop? What wood prop came with the 447 firestars or fireflies of yore? What are the recommended composite props these days?
 >  I had an unmarked (brand) 60x40 wood prop that gave me 60 mph cruise in a Hawk burning 1.5 gallons an hour consistently. Before that I had a 60x38 Culver (made in PA) that burned closer to 1.8 gal/hr cruising at 60. I still have the 60x40 but long story short, it's split from hitting a green jolly rancher candy and that ruined it so it hangs on my living room wall. I wish I knew the brand as I'd buy one in a heartbeat but my guess it was a Tennessee prop.
 >
 > Thanks,
 > Jay
 >
 >
 >
 >
 
 
 
 
 | 
 
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		| tkrolfe(at)toast.net Guest
 
 
 
 
 
 
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				|  Posted: Thu Jul 13, 2023 9:00 am    Post subject: prop recommendations for 447 on firestar or firefly |   |  
				| 
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				| Wow! 4Gal per hour is extreme.  I have a 66" two blade IVO on my Firefly 
after having replaced the Tennessee 66" prop many years ago.   447 B box
 and have consistently gotten a rate of 2 gal per hour from both.
 Reaching 65 mph at 5000 rpm means your probably over pitched.  My friend
 who has a FireStar II with a 503 and a 68" two blade IVO gets a little
 over 2 gal per hour on his.  We generally cruise at 4800 rpm.  For what
 it's worth.
 On 7/12/2023 7:12 PM, Stuart Harner wrote:
 
  	  | Quote: |  	  | 
 My Firefly has a 60" 3 blade Warp Drive on the 447 with a 2.58:1 "B" box.
 
 Smooth, quiet and powerful, but I don't get much better than 4 G/Hr.
 4800 to 5000 engine RPM will push the Firefly ~65 MPH.
 
 The 3 blade makes it fit in the camper/hangar nicely.
 On 7/12/23 17:31, Jay Dub wrote:
 >
 >
 > I have a 68" Ivoprop ground adjustable that came with my 447 (both
 > used)for my Firestar. Does anyone know what the recommended prop
 > diameter/pitch is for the 447 powered firestar or firefly? I have
 > flown with Ivoprops in the past and never cared for them (it seems
 > the flex/coning gives them a lot of "slip" making them very
 > inefficient, but I could be wrong). Every ultralight in the 90's I
 > flew with an ivo burned a lot more fuel than the fixed 60x38 or 60x40
 > wood props and took longer in takeoff  as well as cruised slower (my
 > own observations but that was all with CGS Hawks flying 447s and not
 > Kolbs). Since wood props are just as or more expensive these days as
 > to a composite, I'm wondering what the wisdom is these days for a
 > prop? What wood prop came with the 447 firestars or fireflies of
 > yore? What are the recommended composite props these days?
 >   I had an unmarked (brand) 60x40 wood prop that gave me 60 mph
 > cruise in a Hawk burning 1.5 gallons an hour consistently. Before
 > that I had a 60x38 Culver (made in PA) that burned closer to 1.8
 > gal/hr cruising at 60. I still have the 60x40 but long story short,
 > it's split from hitting a green jolly rancher candy and that ruined
 > it so it hangs on my living room wall. I wish I knew the brand as I'd
 > buy one in a heartbeat but my guess it was a Tennessee prop.
 >
 > Thanks,
 > Jay
 >
 >
 
 
 | 
 
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		| stuart(at)harnerfarm.net Guest
 
 
 
 
 
 
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				|  Posted: Thu Jul 13, 2023 10:03 am    Post subject: prop recommendations for 447 on firestar or firefly |   |  
				| 
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				| Now that I think about it, I may have mis-spoke about the RPM. It has 
been many years since I last flew so I went back and looked at the charts.
 
 I think cruise ~65 takes abut 5800 RPM and I was using 4800 for powered
 descents. My Firefly really likes 63 MPH indicated. It will easily go
 way faster than that but anything above 65 and you can feel it protesting.
 
 I do remember that I followed the book for initial pitch set up. Full
 throttle while tied down should produce "x" RPM. I remember adjusting
 the pitch a few times to get this dialed in. After that it was off to
 flying but I never had an opportunity to do any really good pattern work
 or more tuning on the engine. Just too much traffic at the local
 "little" airport. I would take off and get the heck away from there just
 to go flying, then run the gauntlet through the traffic going every
 which direction to try and land without being run over. Only got about
 15 hours in the air before I gave up.
 
 Looking at the Rotax chart for the 447 it says fuel consumption is
 supposed to be 4 GPH at 5500 RPM. I never figured it could be anything
 much less than maybe 3.5 GPH.
 
 Oh well,
 
 Stuart
 
 On 7/13/23 11:59, Terry Frantz wrote:
 
  	  | Quote: |  	  | 
 Wow! 4Gal per hour is extreme.  I have a 66" two blade IVO on my
 Firefly after having replaced the Tennessee 66" prop many years ago.
 447 B box and have consistently gotten a rate of 2 gal per hour from
 both.  Reaching 65 mph at 5000 rpm means your probably over pitched.
 My friend who has a FireStar II with a 503 and a 68" two blade IVO
 gets a little over 2 gal per hour on his.  We generally cruise at 4800
 rpm.  For what it's worth.
 On 7/12/2023 7:12 PM, Stuart Harner wrote:
 >
 >
 > My Firefly has a 60" 3 blade Warp Drive on the 447 with a 2.58:1 "B"
 > box.
 >
 > Smooth, quiet and powerful, but I don't get much better than 4 G/Hr.
 > 4800 to 5000 engine RPM will push the Firefly ~65 MPH.
 >
 > The 3 blade makes it fit in the camper/hangar nicely.
 > On 7/12/23 17:31, Jay Dub wrote:
 >>
 >>
 >> I have a 68" Ivoprop ground adjustable that came with my 447 (both
 >> used)for my Firestar. Does anyone know what the recommended prop
 >> diameter/pitch is for the 447 powered firestar or firefly? I have
 >> flown with Ivoprops in the past and never cared for them (it seems
 >> the flex/coning gives them a lot of "slip" making them very
 >> inefficient, but I could be wrong). Every ultralight in the 90's I
 >> flew with an ivo burned a lot more fuel than the fixed 60x38 or
 >> 60x40 wood props and took longer in takeoff  as well as cruised
 >> slower (my own observations but that was all with CGS Hawks flying
 >> 447s and not Kolbs). Since wood props are just as or more expensive
 >> these days as to a composite, I'm wondering what the wisdom is these
 >> days for a prop? What wood prop came with the 447 firestars or
 >> fireflies of yore? What are the recommended composite props these days?
 >>   I had an unmarked (brand) 60x40 wood prop that gave me 60 mph
 >> cruise in a Hawk burning 1.5 gallons an hour consistently. Before
 >> that I had a 60x38 Culver (made in PA) that burned closer to 1.8
 >> gal/hr cruising at 60. I still have the 60x40 but long story short,
 >> it's split from hitting a green jolly rancher candy and that ruined
 >> it so it hangs on my living room wall. I wish I knew the brand as
 >> I'd buy one in a heartbeat but my guess it was a Tennessee prop.
 >>
 >> Thanks,
 >> Jay
 >>
 >>
 >>
 >>
 >
 
 
 
 | 
 
 | |  |  | - The Matronics Kolb-List Email Forum - |  |  |  | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:http://www.matronics.com/Navigator?Kolb-List
 
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		| jaydub 
 
 
 Joined: 07 Jan 2020
 Posts: 74
 
 
 | 
			
				|  Posted: Mon Jul 17, 2023 3:19 pm    Post subject: prop recommendations for 447 on firestar or firefly |   |  
				| 
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				| Thanks for the info on props. I'm still wondering what the dia/pitch of wood props were for Firestars when they used wood props in the 80's and 90's?
 I did call Kolb and talked with Tom this morning. He said they are recommending the Ivoprop, Powerfin, or the Ultraprop II. They recommend 62-64" dia 2 or 3 blade.
 
 My Ivo can be cut down from 68" to 64" according to Ivo so I might just do that.
 
 Jay
 
 Sent: Thursday, July 13, 2023 at 12:03 PM
 From: "Stuart Harner" <stuart(at)harnerfarm.net>
 To: kolb-list(at)matronics.com
 Subject: Re: prop recommendations for 447 on firestar or firefly
 
 
 Now that I think about it, I may have mis-spoke about the RPM. It has
 been many years since I last flew so I went back and looked at the charts.
 
 I think cruise ~65 takes abut 5800 RPM and I was using 4800 for powered
 descents. My Firefly really likes 63 MPH indicated. It will easily go
 way faster than that but anything above 65 and you can feel it protesting.
 
 I do remember that I followed the book for initial pitch set up. Full
 throttle while tied down should produce "x" RPM. I remember adjusting
 the pitch a few times to get this dialed in. After that it was off to
 flying but I never had an opportunity to do any really good pattern work
 or more tuning on the engine. Just too much traffic at the local
 "little" airport. I would take off and get the heck away from there just
 to go flying, then run the gauntlet through the traffic going every
 which direction to try and land without being run over. Only got about
 15 hours in the air before I gave up.
 
 Looking at the Rotax chart for the 447 it says fuel consumption is
 supposed to be 4 GPH at 5500 RPM. I never figured it could be anything
 much less than maybe 3.5 GPH.
 
 Oh well,
 
 Stuart
 
 On 7/13/23 11:59, Terry Frantz wrote:
 
  	  | Quote: |  	  | 
 Wow! 4Gal per hour is extreme.  I have a 66" two blade IVO on my
 Firefly after having replaced the Tennessee 66" prop many years ago.
 447 B box and have consistently gotten a rate of 2 gal per hour from
 both.  Reaching 65 mph at 5000 rpm means your probably over pitched.
 My friend who has a FireStar II with a 503 and a 68" two blade IVO
 gets a little over 2 gal per hour on his.  We generally cruise at 4800
 rpm.  For what it's worth.
 On 7/12/2023 7:12 PM, Stuart Harner wrote:
 >
 >
 > My Firefly has a 60" 3 blade Warp Drive on the 447 with a 2.58:1 "B"
 > box.
 >
 > Smooth, quiet and powerful, but I don't get much better than 4 G/Hr.
 > 4800 to 5000 engine RPM will push the Firefly ~65 MPH.
 >
 > The 3 blade makes it fit in the camper/hangar nicely.
 > On 7/12/23 17:31, Jay Dub wrote:
 >>
 >>
 >> I have a 68" Ivoprop ground adjustable that came with my 447 (both
 >> used)for my Firestar. Does anyone know what the recommended prop
 >> diameter/pitch is for the 447 powered firestar or firefly? I have
 >> flown with Ivoprops in the past and never cared for them (it seems
 >> the flex/coning gives them a lot of "slip" making them very
 >> inefficient, but I could be wrong). Every ultralight in the 90's I
 >> flew with an ivo burned a lot more fuel than the fixed 60x38 or
 >> 60x40 wood props and took longer in takeoff  as well as cruised
 >> slower (my own observations but that was all with CGS Hawks flying
 >> 447s and not Kolbs). Since wood props are just as or more expensive
 >> these days as to a composite, I'm wondering what the wisdom is these
 >> days for a prop? What wood prop came with the 447 firestars or
 >> fireflies of yore? What are the recommended composite props these days?
 >>   I had an unmarked (brand) 60x40 wood prop that gave me 60 mph
 >> cruise in a Hawk burning 1.5 gallons an hour consistently. Before
 >> that I had a 60x38 Culver (made in PA) that burned closer to 1.8
 >> gal/hr cruising at 60. I still have the 60x40 but long story short,
 >> it's split from hitting a green jolly rancher candy and that ruined
 >> it so it hangs on my living room wall. I wish I knew the brand as
 >> I'd buy one in a heartbeat but my guess it was a Tennessee prop.
 >>
 >> Thanks,
 >> Jay
 >>
 >>
 >>
 >>
 >
 
 
 
 | 
 
 
 
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