---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Wed 07/12/23: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 03:31 PM - prop recommendations for 447 on firestar or firefly (Jay Dub) 2. 04:20 PM - Re: prop recommendations for 447 on firestar or firefly (Stuart Harner) 3. 04:41 PM - Re: prop recommendations for 447 on firestar or firefly (Larry Cottrell) 4. 04:41 PM - Re: prop recommendations for 447 on firestar or firefly (George Helton) ________________________________ Message 1 _____________________________________ Time: 03:31:50 PM PST US From: Jay Dub Subject: Kolb-List: prop recommendations for 447 on firestar or firefly 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/coninggives 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 ________________________________ Message 2 _____________________________________ Time: 04:20:47 PM PST US Subject: Re: Kolb-List: prop recommendations for 447 on firestar or firefly From: Stuart Harner 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/coninggives 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 > > ________________________________ Message 3 _____________________________________ Time: 04:41:09 PM PST US From: Larry Cottrell Subject: Re: Kolb-List: prop recommendations for 447 on firestar or firefly 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 4:34PM 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 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. ________________________________ Message 4 _____________________________________ Time: 04:41:41 PM PST US From: George Helton Subject: Re: Kolb-List: prop recommendations for 447 on firestar or firefly Sent from my iPhone > On Jul 12, 2023, at 7:30 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 >> >> >> >> > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kolb-list Browse Digests http://www.matronics.com/digest/kolb-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.