From: krnet-bounces@mylist.net To: John Bouyea Subject: KRnet Digest, Vol 347, Issue 237 Date: 6/17/2005 11:54:30 AM Send KRnet mailing list submissions to krnet@mylist.net To subscribe or unsubscribe via the World Wide Web, visit http://mylist.net/listinfo/krnet or, via email, send a message with subject or body 'help' to krnet-request@mylist.net You can reach the person managing the list at krnet-owner@mylist.net When replying, please edit your Subject line so it is more specific than "Re: Contents of KRnet digest..." Today's Topics: 1. Glide ratios and other such things.... (IFLYKRS@aol.com) 2. Re: glide rato.. (Kenneth B. Jones) 3. Re: glide rato.. (Kenneth B. Jones) 4. Re: RE: what a day (Mark Langford) 5. Re: what a day./ glide rato.. (Mark Langford) 6. Re: glide rato.. (Dennis Mingear) 7. Re: glide rato.. (Dennis Mingear) 8. Re: Glide ratios and other such things.... (Dennis Mingear) 9. Re:Prop extensions. (paulwasp@webtv.net) 10. Re: Re:Prop extensions. (Mark Langford) 11. RE: glide rato.. (Golden, Kevin) 12. Re: Re:Prop extensions. (Dan Heath) 13. Re: Re:Prop extensions. (Orma) 14. Re: Re:Prop extensions. (Orma) 15. RE: glide rato.. (Richard Green) 16. Gilbert Duty Engines. (Dan Heath) 17. Re: glide rato.. (Mark Langford) ---------------------------------------------------------------------- Message: 1 Date: Fri, 17 Jun 2005 01:35:14 EDT From: IFLYKRS@aol.com Subject: KR> Glide ratios and other such things.... To: krnet@mylist.net Message-ID: Content-Type: text/plain; charset="US-ASCII" The only real test on glide ratios that I have done brings me to conclude that my plane at 90 mph best glide (assumed) gives me about 2.5 miles for every 1000 feet of altitude lost. Im not sure of the actual ratio but I try to fly a minimum of 5000 AGL when possible - usually higher - on long cross country flights to always give me the best possible margins of safety and performance. I can normally land at an airport anywhere along most routes I take when properly planned. Sometimes weather interfers but then I change my routing to a less direct route and fly airport to airport. When I fly around here I have made notes on my charts and waypoints in my GPS as to where all the private strips are at. Many are not on charts and I have found many that help me make more direct paths- especially when I fly southeast of Valdosta I can choose to fly 35 minutes over swamp with no landing strips in sight or take a slightly less direct route and add only 3 minutes but be in gliding distance of an airport (private and paved) during the entire route. I prefer the longer route as it causes less of a "pucker" factor. This sound very different in an airplane when flying over water or snake infested swamps. I will also fly above broken and scattered layers on long cross country flights rather than fly low. Jusr be careful not to fly over solid layers where you run out of options to descend. The use of GPS is nice during these flights. At 9,000 - 14000 the air is cool, usually calm and more stable. I would sacrifice speed due to headwind for a higher altitude anytime. The KR is efficient enough to allow this and a few minutes extra is a small sacrifice for safety. Ive done many flights above 9000 and enjoy it. This airplane climb very fast and will do even better with the turbo (in progress). All this is a just a reminder that flying can be hazardous to ones health - plan and think accordingly. An engine rebuild is a small price to pay when considering the cost of your life and the loss and effects on family and friends. I fly for fun and for business. I plan to do so as long as I can. It is something I enjoy and I enjoy sharing it with my friends. Im not scared to fly though it has given my a scare a time or two, but no more than driving at night and scaring myself when I doze off for a split second. I sometimes see pilots who are overconfident of a "production" aircraft and engine and dont fly accordingly. I myself have looked back and wondered why I flew so low in a 150 on a cross country flight and realized that I assumed nothing could go wrong yet give myself more margins with my plane that I built myself. The 150 was a rental I knew little about, its damage history, repairs, did the last pilot not mention a problem, maintenance...and so forth. Yet many times I hopped in and flew with confidence, and now I believe it to be overconfidence. Airplanes are mechanical things and they DO break. We just have to learn to fly preemtively and build to the best of our ability. Dont be scared to build - get help when needed - build with safety in mind and learn from those of us who have broken things or made poor choices. I think all of us have invaluable build and flight information that can inspire and motivate others and ourselves to enjoy the wonder of flight. So Mark Langford - he will get his engine fixed, do the repairs and tweaking and be back in the air soon - KUDOS to him And Bob Lester - recuperating from his back injury - doing well - and he is in the process of building new main spars fand engine for his plane to get him airborne again - KUDOS to him as well - KUDOS to all who pick up the pieces and go on. You are inspirational to us all and make us proud to be in the KR family. Bill and N41768 ------------------------------ Message: 2 Date: Fri, 17 Jun 2005 07:32:48 -0400 From: "Kenneth B. Jones" Subject: Re: KR> glide rato.. To: "KRnet" Message-ID: <017801c57330$4a603290$647ba8c0@oemcomputer> Perhaps the stopped prop is less drag because it's stalled. Below is data taken from my flight test. My idle setting was about 800 to 900 rpm, a little high, at the time. Speeds are indicated knots. My plane stalls at about 50 knots indicated so I didn't check the glide below 60 kts. Surely the ratio will start back the other way before it stalls. I have a KR-2 with Diehl wings, 3 blade Warp drive taper blade 58" prop set at 19.5 degrees at the tip, A65, empty weight is 623 lbs., full fuel is 14 gal and I weigh about 180. Glide Speed Descent Distance Glide kts ft/min NM/1000 ft. Ratio 60 400 2.50 15.18 65 442.5 2.45 12.93 70 525 2.22 11.73 75 625 2.00 10.56 80 750 1.78 9.39 85 800 1.77 9.35 90 900 1.67 8.80 95 1100 1.44 7.60 100 1500 1.11 5.87 BTW, Bill's 2.5 miles per 1000 ft altitude is a glide ratio of 13.2 : 1 (if I calculated correctly). Ken Jones, kenbjones@cinci.rr.com Sharonville, OH N5834, aka The Porkopolis Flying Pig ----- Original Message ----- From: "Barry Kruyssen" To: "KRnet" Sent: Thursday, June 16, 2005 6:31 PM Subject: Re: KR> what a day./ glide rato.. > > ----- Original Message ----- From: larry flesner I doubt if a stopped > propeller is going to triple that number > > A stopped prop actually produces less drag, don't know the reason but > have > tried it in self launch gliders (without feathering the prop) both idling > engine and stoped, there is noticeably less drag when the prop was > stopped. Also it is better for the prop to stop vertically so any > vortices from the prop don't upset the air flow over the wing, so I'm told > but I couldn't tell the difference :-) > > regards > Barry Kruyssen ------------------------------ Message: 3 Date: Fri, 17 Jun 2005 07:45:17 -0400 From: "Kenneth B. Jones" Subject: Re: KR> glide rato.. To: "KRnet" Message-ID: <017e01c57332$08745d50$647ba8c0@oemcomputer> Maybe this table will be easier to read. ----- Original Message ----- From: "Kenneth B. Jones" To: "KRnet" Sent: Friday, June 17, 2005 7:32 AM Subject: Re: KR> glide rato.. > Perhaps the stopped prop is less drag because it's stalled. > > Below is data taken from my flight test. My idle setting was about > 800 to > 900 rpm, a little high, at the time. Speeds are indicated knots. My > plane stalls at about 50 knots indicated so I didn't check the glide below > 60 kts. Surely the ratio will start back the other way before it stalls. > I have a KR-2 with Diehl wings, 3 blade Warp drive taper blade 58" prop > set at 19.5 degrees at the tip, A65, empty weight is 623 lbs., full fuel > is 14 gal and I weigh about 180. > > Glide > Speed Descent Distance Glide > kts ft/min NM/1000 ft. Ratio > 60 400 2.50 15.18 > 65 442.5 2.45 12.93 > 70 525 2.22 11.73 > 75 625 2.00 10.56 > 80 750 1.78 9.39 > 85 800 1.77 9.35 > 90 900 1.67 8.80 > 95 1100 1.44 7.60 > 100 1500 1.11 5.87 > > > BTW, Bill's 2.5 miles per 1000 ft altitude is a glide ratio of 13.2 : > 1 > (if I calculated correctly). > > Ken Jones, kenbjones@cinci.rr.com > Sharonville, OH > N5834, aka The Porkopolis Flying Pig > > ----- Original Message ----- > From: "Barry Kruyssen" > To: "KRnet" > Sent: Thursday, June 16, 2005 6:31 PM > Subject: Re: KR> what a day./ glide rato.. > > >> >> ----- Original Message ----- From: larry flesner I doubt if a stopped >> propeller is going to triple that number >> >> A stopped prop actually produces less drag, don't know the reason but >> have tried it in self launch gliders (without feathering the prop) both >> idling engine and stoped, there is noticeably less drag when the prop was >> stopped. Also it is better for the prop to stop vertically so any >> vortices from the prop don't upset the air flow over the wing, so I'm >> told but I couldn't tell the difference :-) >> >> regards >> Barry Kruyssen > ------------------------------ Message: 4 Date: Fri, 17 Jun 2005 07:24:17 -0500 From: "Mark Langford" Subject: Re: KR> RE: what a day To: "KRnet" Message-ID: <002b01c57337$7b2f7370$5e0ca58c@net.tbe.com> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Adriel Michaud wrote: > is not really as bad as it sounds". That's a fantastic attitude. I > would have blown a head gasket at losing the money and (mostly) the > time I had put into that engine. Thanks. I'm actually a pretty negative person. I just play "positive" on KRnet! It's a Jekyl and Hyde thing. > Hmmm, a turbo would make the airplane nice and quiet. . .maybe you do > have a point. But if you go with a front starter arrangement won't > you have to modify your cowling to have a "stubby" nose? I would. I'm still thinking about this... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net ------------------------------ Message: 5 Date: Fri, 17 Jun 2005 07:56:53 -0500 From: "Mark Langford" Subject: Re: KR> what a day./ glide rato.. To: "KRnet" Message-ID: <005f01c5733c$0acd0ed0$5e0ca58c@net.tbe.com> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Larry Flesner wrote: > Assuming you only had a 4 mile distance, 4300 feet AGL, and no wind I > compute the following... Yep, gotta be better than 2.5 to one. I had a 9 knot headwind all the way, was a crosswind once I turned "final", but I didn't even notice it while I was landing. I worked with glides some over the previous weekend, using the GPS's glide function, but I wanted to get the VSI reading correctly to keep me from having to time altitude changes. By the way, Wednesday's flight, the VSI was fairly accurate, but I'd disconnected it from the static system, so somehow it was still driving it crazy. You can rest assured that glide characteristics will be the first thing I work on when I continue testing in a couple of months. I don't know now exactly how far out I was now. Next time I drive to where I was, I'll hit the GOTO button on the GPS and see how far it is to HUA. Whatever the ratio is, it was just barely enough! I'm also going to send the EIS to GRT to have the altitude and airspeed functions added to it, so I'll have a complete record "next time"... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net ------------------------------ Message: 6 Date: Fri, 17 Jun 2005 06:55:36 -0700 (PDT) From: Dennis Mingear Subject: Re: KR> glide rato.. To: KRnet Message-ID: <20050617135536.60528.qmail@web51408.mail.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 With the engine running at idle the challenge is to determine if you are producing thrust or drag. The CAFE association uses a sensor on the engine to determine where the "zero thrust point" is by measuring the fore and aft movement of the crankshaft. If they are producing thrust the crank pulls forward slightly, if they are producing drag the crank moves back slightly. By using the sensor they can get a reasonable determination of the "zero thrust point" on the engine and then accurately determine the planes real L/D. Motorglider pilots are famous for setting their thrust for a minimal sink rate while soaring, they get fantastic L/D's using that approach. Denny ... --- "Kenneth B. Jones" wrote: > Maybe this table will be easier to read. > > ----- Original Message ----- > From: "Kenneth B. Jones" > To: "KRnet" > Sent: Friday, June 17, 2005 7:32 AM > Subject: Re: KR> glide rato.. > > > > Perhaps the stopped prop is less drag because it's > stalled. > > > > Below is data taken from my flight test. My idle > setting was about 800 to > > 900 rpm, a little high, at the time. Speeds are > indicated knots. My > > plane stalls at about 50 knots indicated so I > didn't check the glide below > > 60 kts. Surely the ratio will start back the other > way before it stalls. > > I have a KR-2 with Diehl wings, 3 blade Warp drive > taper blade 58" prop > > set at 19.5 degrees at the tip, A65, empty weight > is 623 lbs., full fuel > > is 14 gal and I weigh about 180. > > > > Glide > > Speed Descent Distance Glide > > kts ft/min NM/1000 ft. > Ratio > > > > 60 400 2.50 > 15.18 > > 65 442.5 2.45 > 12.93 > > 70 525 2.22 > 11.73 > > 75 625 2.00 > 10.56 > > 80 750 1.78 > 9.39 > > 85 800 1.77 > 9.35 > > 90 900 1.67 > 8.80 > > 95 1100 1.44 > 7.60 > > 100 1500 1.11 > 5.87 > > > > > > BTW, Bill's 2.5 miles per 1000 ft altitude is a > glide ratio of 13.2 : 1 > > (if I calculated correctly). > > > > Ken Jones, kenbjones@cinci.rr.com > > Sharonville, OH > > N5834, aka The Porkopolis Flying Pig > > > > ----- Original Message ----- > > From: "Barry Kruyssen" > > To: "KRnet" > > Sent: Thursday, June 16, 2005 6:31 PM > > Subject: Re: KR> what a day./ glide rato.. > > > > > >> > >> ----- Original Message ----- From: larry flesner > I doubt if a stopped > >> propeller is going to triple that number > >> > >> A stopped prop actually produces less drag, don't > know the reason but > >> have tried it in self launch gliders (without > feathering the prop) both > >> idling engine and stoped, there is noticeably > less drag when the prop was > >> stopped. Also it is better for the prop to stop > vertically so any > >> vortices from the prop don't upset the air flow > over the wing, so I'm > >> told but I couldn't tell the difference :-) > >> > >> regards > >> Barry Kruyssen > > > > > > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to > KRnet-leave@mylist.net > please see other KRnet info at > http://www.krnet.org/info.html > "I can train a monkey to wave an American flag. That does not make the monkey patriotic." Scott Ritter __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------ Message: 7 Date: Fri, 17 Jun 2005 07:01:59 -0700 (PDT) From: Dennis Mingear Subject: Re: KR> glide rato.. To: KRnet Message-ID: <20050617140159.40621.qmail@web51403.mail.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 If the prop stops in a horizontal position it will disturb the airflow over the wing, making it seem smaller than it actually is, this will reduce the planes L/D. If the prop stops vertically the airflow over the wing is not disturbed and you have more effective wing area, producing more lift, which improves the planes L/D. If the prop is windmilling it is intermittantly disturbing the airflow over the wing which is hurting the wings ability to produce lift and hurting the planes L/D. Denny ... --- "Kenneth B. Jones" wrote: > Perhaps the stopped prop is less drag because it's > stalled. > > Below is data taken from my flight test. My idle > setting was about 800 to > 900 rpm, a little high, at the time. Speeds are > indicated knots. My plane > stalls at about 50 knots indicated so I didn't check > the glide below 60 kts. > Surely the ratio will start back the other way > before it stalls. I have a > KR-2 with Diehl wings, 3 blade Warp drive taper > blade 58" prop set at 19.5 > degrees at the tip, A65, empty weight is 623 lbs., > full fuel is 14 gal and I > weigh about 180. > > Glide > Speed Descent Distance Glide > kts ft/min NM/1000 ft. Ratio > 60 400 2.50 15.18 > 65 442.5 2.45 12.93 > 70 525 2.22 11.73 > 75 625 2.00 10.56 > 80 750 1.78 9.39 > 85 800 1.77 9.35 > 90 900 1.67 8.80 > 95 1100 1.44 7.60 > 100 1500 1.11 5.87 > > > BTW, Bill's 2.5 miles per 1000 ft altitude is a > glide ratio of 13.2 : 1 (if > I calculated correctly). > > Ken Jones, kenbjones@cinci.rr.com > Sharonville, OH > N5834, aka The Porkopolis Flying Pig > > ----- Original Message ----- > From: "Barry Kruyssen" > To: "KRnet" > Sent: Thursday, June 16, 2005 6:31 PM > Subject: Re: KR> what a day./ glide rato.. > > > > > > ----- Original Message ----- From: larry flesner > I doubt if a stopped > > propeller is going to triple that number > > > > A stopped prop actually produces less drag, don't > know the reason but have > > tried it in self launch gliders (without > feathering the prop) both idling > > engine and stoped, there is noticeably less drag > when the prop was > > stopped. Also it is better for the prop to stop > vertically so any > > vortices from the prop don't upset the air flow > over the wing, so I'm told > > but I couldn't tell the difference :-) > > > > regards > > Barry Kruyssen > > > > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to > KRnet-leave@mylist.net > please see other KRnet info at > http://www.krnet.org/info.html > "I can train a monkey to wave an American flag. That does not make the monkey patriotic." Scott Ritter __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------ Message: 8 Date: Fri, 17 Jun 2005 07:09:13 -0700 (PDT) From: Dennis Mingear Subject: Re: KR> Glide ratios and other such things.... To: KRnet Message-ID: <20050617140913.43965.qmail@web51403.mail.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 That's a glide ratio of just over 13 to 1, you must have a very clean plane or you are producing some thrust. Is this with the engine stopped or with it set to some idle rpm? Denny ... --- IFLYKRS@aol.com wrote: > The only real test on glide ratios that I have done > brings me to conclude > that my plane at 90 mph best glide (assumed) gives > me about 2.5 miles for every > 1000 feet of altitude lost. Im not sure of the > actual ratio but I try to > fly a minimum of 5000 AGL when possible - usually > higher - on long cross country > flights to always give me the best possible margins > of safety and > performance. I can normally land at an airport > anywhere along most routes I take when > properly planned. Sometimes weather interfers but > then I change my routing > to a less direct route and fly airport to airport. > When I fly around here I > have made notes on my charts and waypoints in my GPS > as to where all the > private strips are at. Many are not on charts and I > have found many that help me > make more direct paths- especially when I fly > southeast of Valdosta I can > choose to fly 35 minutes over swamp with no landing > strips in sight or take a > slightly less direct route and add only 3 minutes > but be in gliding distance > of an airport (private and paved) during the entire > route. I prefer the > longer route as it causes less of a "pucker" > factor. This sound very different > in an airplane when flying over water or snake > infested swamps. I will also > fly above broken and scattered layers on long cross > country flights rather > than fly low. Jusr be careful not to fly over > solid layers where you run out of > options to descend. The use of GPS is nice during > these flights. At 9,000 > - 14000 the air is cool, usually calm and more > stable. I would sacrifice > speed due to headwind for a higher altitude > anytime. The KR is efficient enough > to allow this and a few minutes extra is a small > sacrifice for safety. Ive > done many flights above 9000 and enjoy it. This > airplane climb very fast and > will do even better with the turbo (in progress). > All this is a just a reminder that flying can be > hazardous to ones > health - plan and think accordingly. An engine > rebuild is a small price to pay > when considering the cost of your life and the loss > and effects on family and > friends. I fly for fun and for business. I plan > to do so as long as I can. > It is something I enjoy and I enjoy sharing it with > my friends. Im not > scared to fly though it has given my a scare a time > or two, but no more than > driving at night and scaring myself when I doze off > for a split second. I > sometimes see pilots who are overconfident of a > "production" aircraft and engine > and dont fly accordingly. I myself have looked > back and wondered why I flew > so low in a 150 on a cross country flight and > realized that I assumed nothing > could go wrong yet give myself more margins with my > plane that I built > myself. The 150 was a rental I knew little about, > its damage history, repairs, did > the last pilot not mention a problem, > maintenance...and so forth. Yet many > times I hopped in and flew with confidence, and now > I believe it to be > overconfidence. Airplanes are mechanical things and > they DO break. We just have > to learn to fly preemtively and build to the best of > our ability. Dont be > scared to build - get help when needed - build with > safety in mind and learn > from those of us who have broken things or made poor > choices. I think all of > us have invaluable build and flight information > that can inspire and motivate > others and ourselves to enjoy the wonder of flight. > > So Mark Langford - he will get his engine fixed, > do the repairs and > tweaking and be back in the air soon - KUDOS to him > And Bob Lester - recuperating from his back > injury - doing well - and he > is in the process of building new main spars fand > engine for his plane to > get him airborne again - KUDOS to him as well - > KUDOS to all who pick up the pieces and go on. > You are inspirational to > us all and make us proud to be in the KR family. > > Bill and N41768 > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to > KRnet-leave@mylist.net > please see other KRnet info at > http://www.krnet.org/info.html > "I can train a monkey to wave an American flag. That does not make the monkey patriotic." Scott Ritter __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com ------------------------------ Message: 9 Date: Fri, 17 Jun 2005 10:20:16 -0400 From: paulwasp@webtv.net Subject: KR> Re:Prop extensions. To: krnet@mylist.net (KRnet) Message-ID: <7013-42B2DC20-3023@storefull-3233.bay.webtv.net> Content-Type: Text/Plain; Charset=US-ASCII Netters; In light of the recent incidents involving the use of prop extensions: What kind of ext. (steel...aluminum), and what lengths have been succesfully utilized for extended periods. What advice would these builders, flyers, have to offer to us wannabees? What would you consider to be a maximum lengh for an extension to be safely flown with? On corvair, or V/W.... any size engine. Thanks in advance....we learn from such unfortunate experiences as have happened in the past , notably ML's recent harrowing experience. I agree, he could be my wingman anytime! Paul KR2s...2" steel extension Instr. panel, wiring, pitot,static lines Erie, Pa. ------------------------------ Message: 10 Date: Fri, 17 Jun 2005 09:33:29 -0500 From: "Mark Langford" Subject: Re: KR> Re:Prop extensions. To: "KRnet" Message-ID: <011901c57349$88059040$5e0ca58c@net.tbe.com> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original I don't think there's any question that the longer the extension, the higher the liklihood of problems caused by rotational forces. Keep it as short as possible and still allow proper engine cooling. Lighter is better, so aluminum rather than steel. Normally 2024 is best, but I used 6061-T6 and it's fine too. Others with experience on lengths that have worked on various engines are welcome to chime in, I just thought I'd throw out an overview. Bottom line is that unless you are building one exactly by somebody's proven methods (GPASC or William Wynne), we are all experimenting and act as test pilots. Below is something I posted to CorvAircraft this morning: > See http://home.hiwaay.net/~langford/corvair/crank.jpg . WW was here > last > night (happened to be on the way back from SAA) and suspects the prop, > since > it's not a CNC prop, and has been repitched by hand. The break is just > inside the front of the case, right through the edge of the rod journal > (the > radius). You can see from the location of the break that if the prop was > the problem, the long moment arm of the extension will magnify it. He > doesn't attribute the problem to the rear starter setup at all. This > crank > was done by him, so the radiusing is done right (I'd forgotten that > earlier). Right now I think I'm going to build a 2700cc engine, and use > the > same rear starter setup (but stiffen the ring gear some more). I'm still > thinking on the prop hub thing. WW says he put it back together with a > known good crank and prop and try it again. But that prop was magnafluxed > (not to say what quality) by the local machine shop. He's going to sell > me > one that he knows was done right, and I'll put a CNCd prop on it. Still > wondering about the prop extension though. It's tempting to keep it stock > WW. > > Three crank breaks have been in the same place (first rod journal), > the other (Bob's second) was one journal further rearward. WW thinks > that since the three are all broken at the front, torsional vibration > isn't the cause. > I'm going to contact a tosional vibration expert at TCM and see what he > thinks. At this point, I'm tempted to pay him to take a hard look at it > (others may want to get in on this), and make sure we're not doing > something > stupid with the rear starter setup. I'll also start looking into DYI > torsional testing, if there's any such thing. > > More later, but this weekend I'll tear down my 95 hp engine to figure > out what I need to order Monday morning. Tearing this one down will > be later, but I don't think I'm going to find any spun bearings or > that kind of stuff. Oiling has been fine with this thing... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net ------------------------------ Message: 11 Date: Fri, 17 Jun 2005 11:15:13 -0400 From: "Golden, Kevin" Subject: RE: KR> glide rato.. To: 'KRnet' Message-ID: Content-Type: text/plain A windmilling prop does more than disturb air over the airframe. A windmilling prop will cause a huge amount of drag that is NEAR equal to the rotational disc of the prop. Not to worry. I haven't seen a VW or corvair windmill. Lycoming and Continentals will. Kevin. -----Original Message----- From: Dennis Mingear [mailto:dennismingear@yahoo.com] Sent: Friday, June 17, 2005 9:02 AM To: KRnet Subject: Re: KR> glide rato.. If the prop stops in a horizontal position it will disturb the airflow over the wing, making it seem smaller than it actually is, this will reduce the planes L/D. If the prop stops vertically the airflow over the wing is not disturbed and you have more effective wing area, producing more lift, which improves the planes L/D. If the prop is windmilling it is intermittantly disturbing the airflow over the wing which is hurting the wings ability to produce lift and hurting the planes L/D. Denny ... --- "Kenneth B. Jones" wrote: > Perhaps the stopped prop is less drag because it's > stalled. > > Below is data taken from my flight test. My idle > setting was about 800 to > 900 rpm, a little high, at the time. Speeds are > indicated knots. My plane > stalls at about 50 knots indicated so I didn't check > the glide below 60 kts. > Surely the ratio will start back the other way > before it stalls. I have a > KR-2 with Diehl wings, 3 blade Warp drive taper > blade 58" prop set at 19.5 > degrees at the tip, A65, empty weight is 623 lbs., > full fuel is 14 gal and I > weigh about 180. > > Glide > Speed Descent Distance Glide > kts ft/min NM/1000 ft. Ratio > 60 400 2.50 15.18 > 65 442.5 2.45 12.93 > 70 525 2.22 11.73 > 75 625 2.00 10.56 > 80 750 1.78 9.39 > 85 800 1.77 9.35 > 90 900 1.67 8.80 > 95 1100 1.44 7.60 > 100 1500 1.11 5.87 > > > BTW, Bill's 2.5 miles per 1000 ft altitude is a > glide ratio of 13.2 : 1 (if > I calculated correctly). > > Ken Jones, kenbjones@cinci.rr.com > Sharonville, OH > N5834, aka The Porkopolis Flying Pig > > ----- Original Message ----- > From: "Barry Kruyssen" > To: "KRnet" > Sent: Thursday, June 16, 2005 6:31 PM > Subject: Re: KR> what a day./ glide rato.. > > > > > > ----- Original Message ----- From: larry flesner > I doubt if a stopped > > propeller is going to triple that number > > > > A stopped prop actually produces less drag, don't > know the reason but have > > tried it in self launch gliders (without > feathering the prop) both idling > > engine and stoped, there is noticeably less drag > when the prop was > > stopped. Also it is better for the prop to stop > vertically so any > > vortices from the prop don't upset the air flow > over the wing, so I'm told > > but I couldn't tell the difference :-) > > > > regards > > Barry Kruyssen > > > > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to > KRnet-leave@mylist.net > please see other KRnet info at > http://www.krnet.org/info.html > "I can train a monkey to wave an American flag. That does not make the monkey patriotic." Scott Ritter __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net please see other KRnet info at http://www.krnet.org/info.html *The information contained in this message may be confidential and/or subject to legal privilege, and is for the use of the intended addressee only. Any unauthorized use, dissemination or copying of the information in this message is strictly prohibited. If you have received this message in error, please notify the sender immediately and delete this message.* ------------------------------ Message: 12 Date: Fri, 17 Jun 2005 11:22:51 -0400 (Eastern Daylight Time) From: "Dan Heath" Subject: Re: KR> Re:Prop extensions. To: Message-ID: <42B2EACB.000005.03608@DANHOMECOMPUTER> Content-Type: Text/Plain; charset="iso-8859-1" I had a 3" extension on the Little Beast. I flew it for 185 hours without a hint of a problem. The engine was originally a Gilbert Duty that I re-built twice. It started as an 1835, and I sufferred a cracked case behind #3 cylinder, so got another case and re-built it to a 1915. This was all with the same crank and hub extension. Jerry and I have a 3" extension on this GPASC 2180. This already has a "force 1" hub, so I don't know if we have too much or not. Probably if I were doing the extension again, for this engine, I would not go over 2". Richard Shirley had a 2" on his 2180. Both hubs were aluminum. Remember, your results will vary. See you in Mt. Vernon - 2005 - KR Gathering See N64KR at http://KR-Builder.org - Then click on the pics There is a time for building and a time for FLYING and the time for building has expired. Daniel R. Heath - Columbia, SC -------Original Message------- What kind of ext. (steel...aluminum), and what lengths have been succesfully utilized for extended periods. ------------------------------ Message: 13 Date: Fri, 17 Jun 2005 11:45:54 -0400 From: "Orma" Subject: Re: KR> Re:Prop extensions. To: "KRnet" Message-ID: <01da01c57353$a6b3acc0$0302a8c0@ROBBINS1> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Hi Mark Of what kind of material was the prop made of? After the Re-pitch, was the balance rechecked? Was the prop track checked to see if each blade followed the other? In retrospect do you feel that your engine ran as smooth as all the other Corvair aero engines that you have had exposure to? Could it have been vibrating to some minor degree and you did not know it? Orma ------------------------------ Message: 14 Date: Fri, 17 Jun 2005 11:55:24 -0400 From: "Orma" Subject: Re: KR> Re:Prop extensions. To: "KRnet" Message-ID: <01df01c57354$f9d0b960$0302a8c0@ROBBINS1> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original The engine was originally a Gilbert Duty Hi Dan I have not heard the name Duty in quite some time. My original engine was also reportedly a Duty engine. I hope that at some point in his career of engine building that he put together a good engine. Mine was built as a 2000cc, the builder used the cheap aftermarket cylinders that were paper thin and one of mine cracked in the air. I also have a prop extension which is 2" My prop hub came with the engine and takes the place of the front bearing. That part worked well and I reused it on the second engine. Orma Southfield, MI N110LR Tweety, old enough to drink this year Flying and more flying, to the gathering or bust http://www.kr-2.aviation-mechanics.com/ ------------------------------ Message: 15 Date: Fri, 17 Jun 2005 09:21:01 -0700 (PDT) From: Richard Green Subject: RE: KR> glide rato.. To: KRnet Message-ID: <20050617162101.42756.qmail@web81602.mail.yahoo.com> Content-Type: text/plain; charset=iso-8859-1 That is exactly right on the drag created by a windmilling prop....It is about the same as bolting a piece of plywood on the nose that is the equivalant of the rotational disc of the prop. Next time your in a twin, shut one down and try flying with it windmilling and then feather it and you will quickly discover the difference! RG "Golden, Kevin" wrote: A windmilling prop does more than disturb air over the airframe. A windmilling prop will cause a huge amount of drag that is NEAR equal to the rotational disc of the prop. Not to worry. I haven't seen a VW or corvair windmill. Lycoming and Continentals will. Kevin. -----Original Message----- From: Dennis Mingear [mailto:dennismingear@yahoo.com] Sent: Friday, June 17, 2005 9:02 AM To: KRnet Subject: Re: KR> glide rato.. If the prop stops in a horizontal position it will disturb the airflow over the wing, making it seem smaller than it actually is, this will reduce the planes L/D. If the prop stops vertically the airflow over the wing is not disturbed and you have more effective wing area, producing more lift, which improves the planes L/D. If the prop is windmilling it is intermittantly disturbing the airflow over the wing which is hurting the wings ability to produce lift and hurting the planes L/D. Denny ... --- "Kenneth B. Jones" wrote: > Perhaps the stopped prop is less drag because it's > stalled. > > Below is data taken from my flight test. My idle > setting was about 800 to > 900 rpm, a little high, at the time. Speeds are > indicated knots. My plane > stalls at about 50 knots indicated so I didn't check > the glide below 60 kts. > Surely the ratio will start back the other way > before it stalls. I have a > KR-2 with Diehl wings, 3 blade Warp drive taper > blade 58" prop set at 19.5 > degrees at the tip, A65, empty weight is 623 lbs., > full fuel is 14 gal and I > weigh about 180. > > Glide > Speed Descent Distance Glide > kts ft/min NM/1000 ft. Ratio > 60 400 2.50 15.18 > 65 442.5 2.45 12.93 > 70 525 2.22 11.73 > 75 625 2.00 10.56 > 80 750 1.78 9.39 > 85 800 1.77 9.35 > 90 900 1.67 8.80 > 95 1100 1.44 7.60 > 100 1500 1.11 5.87 > > > BTW, Bill's 2.5 miles per 1000 ft altitude is a > glide ratio of 13.2 : 1 (if > I calculated correctly). > > Ken Jones, kenbjones@cinci.rr.com > Sharonville, OH > N5834, aka The Porkopolis Flying Pig > > ----- Original Message ----- > From: "Barry Kruyssen" > To: "KRnet" > Sent: Thursday, June 16, 2005 6:31 PM > Subject: Re: KR> what a day./ glide rato.. > > > > > > ----- Original Message ----- From: larry flesner > I doubt if a stopped > > propeller is going to triple that number > > > > A stopped prop actually produces less drag, don't > know the reason but have > > tried it in self launch gliders (without > feathering the prop) both idling > > engine and stoped, there is noticeably less drag > when the prop was > > stopped. Also it is better for the prop to stop > vertically so any > > vortices from the prop don't upset the air flow > over the wing, so I'm told > > but I couldn't tell the difference :-) > > > > regards > > Barry Kruyssen > > > > > _______________________________________ > Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp > to UNsubscribe from KRnet, send a message to > KRnet-leave@mylist.net > please see other KRnet info at > http://www.krnet.org/info.html > "I can train a monkey to wave an American flag. That does not make the monkey patriotic." Scott Ritter __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net please see other KRnet info at http://www.krnet.org/info.html *The information contained in this message may be confidential and/or subject to legal privilege, and is for the use of the intended addressee only. Any unauthorized use, dissemination or copying of the information in this message is strictly prohibited. If you have received this message in error, please notify the sender immediately and delete this message.* _______________________________________ Search the KRnet Archives at http://www.maddyhome.com/krsrch/index.jsp to UNsubscribe from KRnet, send a message to KRnet-leave@mylist.net please see other KRnet info at http://www.krnet.org/info.html ------------------------------ Message: 16 Date: Fri, 17 Jun 2005 12:31:51 -0400 (Eastern Daylight Time) From: "Dan Heath" Subject: KR> Gilbert Duty Engines. To: Message-ID: <42B2FAF7.00000B.03608@DANHOMECOMPUTER> Content-Type: Text/Plain; charset="iso-8859-1" Yes, old Gilbert had a reputation for building a pretty junky engine. However, not knowing what kind of an engine builder he was, when I got the engine with the plane I bought, I decided to go through the entire engine. The extension came with that engine also. There were a lot of things that needed attention. See you in Mt. Vernon - 2005 - KR Gathering See N64KR at http://KR-Builder.org - Then click on the pics There is a time for building and a time for FLYING and the time for building has expired. Daniel R. Heath - Columbia, SC -------Original Message------- The engine was originally a Gilbert Duty ------------------------------ Message: 17 Date: Fri, 17 Jun 2005 13:53:49 -0500 From: "Mark Langford" Subject: Re: KR> glide rato.. To: "KRnet" Message-ID: <001e01c5736d$e69151c0$5e0ca58c@net.tbe.com> Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Doing the math on 4300 ft over 6.5 miles, you get 8:1. That is if you actually believe it was 6.5 miles, and if my recollection of actual altitude is correct. I'm sure I'd lost some altitude before I got the transponder dialed in and they had a fix on me. A couple of days before the crank problem, I'd discovered the "glide to target" function on my Garmin 195. You can pick an airport, GOTO it, and start a descent, and the GPS will tell you what glide rate you need to make it there, and at the same time what your actual glide ratio is. I guess if it says you can't make it, then you might as well pick somewhere nice along the way! This all assumes that you can actually THINK while this is going on though! I've got to tell you that while I appreciate all the comments about how I kept my cool under pressure, anybody else would have done exactly the same thing....because you have no other choice than to focus on getting back on the ground in one piece! That's where I'll pick up my flight testing when I resume. This time I think I actually have the nerve to switch it off (from high altitude, over the airport), and vary the descent rate while watching the "glide ratio" on the GPS. From that, I'll know for a fact what it is. Maybe that's how Ken did his tests. It would be nice to know if best glide really was as good as his numbers show, down at 60 mph or so. That's a big difference in range... Mark Langford, Huntsville, Alabama see KR2S project N56ML at http://home.hiwaay.net/~langford email to N56ML "at" hiwaay.net ------------------------------ _______________________________________________ See KRnet list details at http://www.krnet.org/instructions.html End of KRnet Digest, Vol 347, Issue 237 *************************************** ================================== ABC Amber Outlook Converter v4.20 Trial version ==================================