---------------------------------------------------------- Kitfox-List Digest Archive --- Total Messages Posted Fri 05/27/11: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:44 AM - Prop settings (rtmarshall) 2. 01:58 PM - Re: Prop settings (Roger Lee) 3. 06:40 PM - Re: Prop settings (Av8r3400) 4. 06:56 PM - Re: Re: Prop settings (rtmarshall) 5. 06:59 PM - Re: Re: Prop settings (rtmarshall) 6. 07:51 PM - Exclusively For You (Marco Menezes) 7. 09:22 PM - Re: Exclusively For You (Ted Palamarek) ________________________________ Message 1 _____________________________________ Time: 07:44:47 AM PST US From: "rtmarshall" Subject: Kitfox-List: Prop settings Hello Kitfox flyers, we are seeking info and opinions on what pitch you set your GSC three blade props(912) for most all around use. Thanks to all for your help. Toodie and Bob ________________________________ Message 2 _____________________________________ Time: 01:58:05 PM PST US Subject: Kitfox-List: Re: Prop settings From: "Roger Lee" Hi Toodie and Bob, There is no hard and fast answer for a pitch, for each aircraft has it's own drag and flight characteristics. But there is a very easy way to arrive at an answer for any plane and any prop. If someone has the same type plane and same prop they can get you close, but you may still need to dial it in for your plane. You need to balance your climb, cruise and fuel with this ground adjustable prop and you don't usually want it to be too far set for climb (flatter pitch) or too much toward cruise (courser pitch). Going either way too far defeats your best all around performance. The Rotax was built and has a specific range of rpms to run within. You need to set the prop to a pitch to achieve 5500-5550 RPM at wide open throttle (WOT). When you set the prop to get this rpm everything else in the middle will take care of itself. You are better off to cruise at 5000-5300 rpm after your prop is pitched at 5500. This setting for a fground adjustable prop will give you the best all around performance for climb, cruise and fuel economy. (While I'm thinking about it set the idle rpm to 1700-1800) Now how to get your prop setup. Tie the plane down. You want enough pitch in your prop to get close to a 5100-5200 static run at WOT. Once you have the static done that only gets you in the ballpark it's time to test fly it and check for rpm and this is where you can get a real pitch number for your individual plane. Each brand of plane and each home built can and will be a little different in prop pitch to achieve the same WOT rpm. So as you test fly your plane run it up to WOT for about 30-45 seconds. See if you are in that 5500-5550 rpm area. A couple rpm either way is no big deal. If your engine rpm tops out at lets say 5400 rpm at WOT then remove another 1/2 degree from the pitch to flatten it a tad more. If you are running 5600 then add about 1/2 degree. That is all there is to dialing in your specific plane to a good all around rpm for the Rotax 912. Here is a picture of what you can use to get good accurate prop pitch settings and uniformity. Here is another picture of a good prop and wheel balancer from Marc Parnes. -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Repair Center Home 520-574-1080 TRY HOME FIRST Cell 520-349-7056 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=341228#341228 Attachments: http://forums.matronics.com//files/img_1144_250.jpg http://forums.matronics.com//files/img_1143_870.jpg ________________________________ Message 3 _____________________________________ Time: 06:40:47 PM PST US Subject: Kitfox-List: Re: Prop settings From: "Av8r3400" Another important thing to note on a 912 is that you must have a minimum of 5200 rpm at full power. Less rpm than that and you are getting too high of cylinder pressure and risk blowing seals. -------- Thanks, Av8r3400 Kitfox Model IV-1200 W/912UL & IVO Kitfox Model IV-1050 W/912UL & Warp Read this topic online here: http://forums.matronics.com/viewtopic.php?p=341246#341246 ________________________________ Message 4 _____________________________________ Time: 06:56:01 PM PST US From: "rtmarshall" Subject: Re: Kitfox-List: Re: Prop settings Thanks Roger, for your extensive explanation of the pitch/RPM. This info is a keeper for future reference. Very informative and helpful, we truly appreciate your time and kindness in answering our question. Haven't flown it yet.....so the anticipation is mounting! But need to address the issues at hand. Toodie and Bob -------------------------------------------------- From: "Roger Lee" Sent: Friday, May 27, 2011 1:55 PM Subject: Kitfox-List: Re: Prop settings Hi Toodie and Bob, There is no hard and fast answer for a pitch, for each aircraft has it's own drag and flight characteristics. But there is a very easy way to arrive at an answer for any plane and any prop. If someone has the same type plane and same prop they can get you close, but you may still need to dial it in for your plane. You need to balance your climb, cruise and fuel with this ground adjustable prop and you don't usually want it to be too far set for climb (flatter pitch) or too much toward cruise (courser pitch). Going either way too far defeats your best all around performance. The Rotax was built and has a specific range of rpms to run within. You need to set the prop to a pitch to achieve 5500-5550 RPM at wide open throttle (WOT). When you set the prop to get this rpm everything else in the middle will take care of itself. You are better off to cruise at 5000-5300 rpm after your prop is pitched at 5500. This setting for a fground adjustable prop will give you the best all arou! nd performance for climb, cruise and fuel economy. (While I'm thinking about it set the idle rpm to 1700-1800) Now how to get your prop setup. Tie the plane down. You want enough pitch in your prop to get close to a 5100-5200 static run at WOT. Once you have the static done that only gets you in the ballpark it's time to test fly it and check for rpm and this is where you can get a real pitch number for your individual plane. Each brand of plane and each home built can and will be a little different in prop pitch to achieve the same WOT rpm. So as you test fly your plane run it up to WOT for about 30-45 seconds. See if you are in that 5500-5550 rpm area. A couple rpm either way is no big deal. If your engine rpm tops out at lets say 5400 rpm at WOT then remove another 1/2 degree from the pitch to flatten it a tad more. If you are running 5600 then add about 1/2 degree. That is all there is to dialing in your specific plane to a good all around rpm for the Rotax 912. Here is a picture of what you can use to get good accurate prop pitch settings and uniformity. Here is another picture of a good prop and wheel balancer from Marc Parnes. -------- Roger Lee Tucson, Az. Light Sport Repairman - Maintenance Rated Rotax Repair Center Home 520-574-1080 TRY HOME FIRST Cell 520-349-7056 Read this topic online here: http://forums.matronics.com/viewtopic.php?p=341228#341228 Attachments: http://forums.matronics.com//files/img_1144_250.jpg http://forums.matronics.com//files/img_1143_870.jpg ________________________________ Message 5 _____________________________________ Time: 06:59:02 PM PST US From: "rtmarshall" Subject: Re: Kitfox-List: Re: Prop settings Thanks AV8R3400, much appreciated as we are in the steep learning curve and this is such valuable information. Toodie and Bob -------------------------------------------------- From: "Av8r3400" Sent: Friday, May 27, 2011 6:37 PM Subject: Kitfox-List: Re: Prop settings Another important thing to note on a 912 is that you must have a minimum of 5200 rpm at full power. Less rpm than that and you are getting too high of cylinder pressure and risk blowing seals. -------- Thanks, Av8r3400 Kitfox Model IV-1200 W/912UL & IVO Kitfox Model IV-1050 W/912UL & Warp Read this topic online here: http://forums.matronics.com/viewtopic.php?p=341246#341246 ________________________________ Message 6 _____________________________________ Time: 07:51:58 PM PST US From: Marco Menezes Subject: Kitfox-List: Exclusively For You I've found an amazing offer http://goo.gl/r3EEi Enjoy it! ________________________________ Message 7 _____________________________________ Time: 09:22:01 PM PST US From: "Ted Palamarek" Subject: RE: Kitfox-List: Exclusively For You Marco I think you have a virus in your computer and it is spewing out a bunch of ads. Ted Palamarek Edmonton, Ab -----Original Message----- From: owner-kitfox-list-server@matronics.com [mailto:owner-kitfox-list-server@matronics.com] On Behalf Of Marco Menezes Sent: Friday, May 27, 2011 8:49 PM Subject: Kitfox-List: Exclusively For You I've found an amazing offer http://goo.gl/r3EEi Enjoy it! ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kitfox-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kitfox-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/kitfox-list Browse Digests http://www.matronics.com/digest/kitfox-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.