---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Sat 10/13/07: 11 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:07 AM - Question about short fuse with a Corvair (Ryan Mueller) 2. 04:30 AM - Re: Question about short fuse with a Corvair (RAMPEYBOY@aol.com) 3. 07:20 AM - Re: Question about short fuse with a Corvair (Skip Gadd) 4. 07:22 AM - Re: Question about short fuse with a Corvair (Roman Bukolt) 5. 08:02 AM - Re: Question about short fuse with a Corvair (Ryan Mueller) 6. 08:08 AM - Re: Question about short fuse with a Corvair (RAMPEYBOY@aol.com) 7. 08:32 AM - Re: Question about short fuse with a Corvair (Max Hegler) 8. 08:35 AM - Re: Question about short fuse with a Corvair (Max Hegler) 9. 09:54 AM - Re: Question about short fuse with a Corvair (Ryan Mueller) 10. 10:18 AM - Re: Question about short fuse with a Corvair (Ryan Mueller) 11. 10:38 AM - Re: Question about short fuse with a Corvair (Roman Bukolt) ________________________________ Message 1 _____________________________________ Time: 04:07:53 AM PST US From: Ryan Mueller Subject: Pietenpol-List: Question about short fuse with a Corvair I have a question regarding the need for the long fuselage when using a Corvair engine. Based on most of what I have read, the justification is that the long fuselage was developed to meet W&B requirements when using the Corvair/Continentals. What I fail to understand is how having a longer fuselage helps that issue, for this reason: lengthening the fuselage increases the moments for any weight that is moved aft. Therefore the structure of a long fuselage would have more wood farther aft of the datum than not, for lack of better phrasing. In addition, having the rear cockpit farther aft will only increase the arm of the pilot's weight. I don't see how moving more weight farther aft to compensate for a lighter engine up front computes. I understand the long fuse has more room inside. I was able to sit in the Last Original at Brodhead and had a generous amount of legroom, and my wife is shorter than I was, so I don't think the short fuse would cramp us. We would then be able to build a lighter aircraft. Finally, I would think at my weight (220) I would have to take less drastic measures to get a short fuse Corvair Piet to balance out than a long fuselage version. Any thoughts? Ryan --------------------------------- Take the Internet to Go: Yahoo!Go puts the Internet in your pocket: mail, news, photos & more. ________________________________ Message 2 _____________________________________ Time: 04:30:57 AM PST US From: RAMPEYBOY@aol.com Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Ryan, I'm glad you asked this question. I have been studying the Pietenpol for a while now, and have wondered the same thing! I look forward to hearing everyone's responses! Boyce ________________________________ Message 3 _____________________________________ Time: 07:20:44 AM PST US From: "Skip Gadd" Subject: RE: Pietenpol-List: Question about short fuse with a Corvair Ryan, The small Continentals may be lighter than a Model A, but if you put a starter and charging system on a Corvair it will be about the same weight as the ford. I am building the Flying & Glider fuselage which is almost a foot shorter than the Corvair fuse and I am going to use the Corvair. I agree that the short fuse should be easier to get the CG correct. The tail post of the corvair fuse is over 5" further aft of the pilot then the shorter fuselages. Skip I have a question regarding the need for the long fuselage when using a Corvair engine. Based on most of what I have read, the justification is that the long fuselage was developed to meet W&B requirements when using the Corvair/Continentals. Ryan ________________________________ Message 4 _____________________________________ Time: 07:22:45 AM PST US From: "Roman Bukolt" Subject: Re: Pietenpol-List: Question about short fuse with a Corvair The Corvair engine weight about 230 lbs. The Continental weighs about 170 lbs. To keep the C.G. no further aft then 33% of the chord, you must offset the heavier Corvair with more weight in the the tail. My Piet was originally built long to accomodate a Corvair. Even then added weight was installed way back in the tail. Then the Corvair froze up and and was replaced with a Cont. A-65. When I bought the plane the C.G. was at 39%. Seriously tail heavy. Luckily I had Bill Rewey doing the landings and take offs when we flew the plane back to Madison, Wi. from Iowa. Since then I corrected the C.G. by installing a 30lb. 12v battery on the firewall. The C.G. is the balance point. All the weight ahead of the C.G. must equal all the weight aft of the C.G. The heavier engine in front requires more weight aft. A longer moment aft requires les weight than a short moment aft. And lightness is a good thing. Heaviness is not a good thing. The longer the moment, the less weight required. Roman Bukolt NX20795 ----- Original Message ----- From: Ryan Mueller To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 6:06 AM Subject: Pietenpol-List: Question about short fuse with a Corvair I have a question regarding the need for the long fuselage when using a Corvair engine. Based on most of what I have read, the justification is that the long fuselage was developed to meet W&B requirements when using the Corvair/Continentals. What I fail to understand is how having a longer fuselage helps that issue, for this reason: lengthening the fuselage increases the moments for any weight that is moved aft. Therefore the structure of a long fuselage would have more wood farther aft of the datum than not, for lack of better phrasing. In addition, having the rear cockpit farther aft will only increase the arm of the pilot's weight. I don't see how moving more weight farther aft to compensate for a lighter engine up front computes. I understand the long fuse has more room inside. I was able to sit in the Last Original at Brodhead and had a generous amount of legroom, and my wife is shorter than I was, so I don't think the short fuse would cramp us. We would then be able to build a lighter aircraft. Finally, I would think at my weight (220) I would have to take less drastic measures to get a short fuse Corvair Piet to balance out than a long fuselage version. Any thoughts? Ryan ________________________________ Message 5 _____________________________________ Time: 08:02:39 AM PST US From: Ryan Mueller Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Regarding what you said about offsetting the heaver Corvair with more weight in the tail.... A Corvair engine is heavier than a Continental, yes. The long fuse was designed with the Corvair in mind, but since the Corvair is approximately 15 to 20 pounds lighter than Model A, why the need for the longer fuselage? As best I can figure, a Corvair with a short fuselage would therefore potentially be tail heavy (since there is a little less weight forward of the CG), which would be corrected by lengthening the engine mount (to extend the moment of the engine) and/or adjusting the cabane struts. If, in order to correct it, you then lengthen the fuselage and put more structure aft of the CG, in addition to moving the pilot slightly farther aft, this would only exacerbate an already tail heavy condition. Am I confused in my thinking? Ryan Roman Bukolt wrote: The Corvair engine weight about 230 lbs. The Continental weighs about 170 lbs. To keep the C.G. no further aft then 33% of the chord, you must offset the heavier Corvair with more weight in the the tail. My Piet was originally built long to accomodate a Corvair. Even then added weight was installed way back in the tail. Then the Corvair froze up and and was replaced with a Cont. A-65. When I bought the plane the C.G. was at 39%. Seriously tail heavy. Luckily I had Bill Rewey doing the landings and take offs when we flew the plane back to Madison, Wi. from Iowa. Since then I corrected the C.G. by installing a 30lb. 12v battery on the firewall. The C.G. is the balance point. All the weight ahead of the C.G. must equal all the weight aft of the C.G. The heavier engine in front requires more weight aft. A longer moment aft requires les weight than a short moment aft. And lightness is a good thing. Heaviness is not a good thing. The longer the moment, the less weight required. Roman Bukolt NX20795 ----- Original Message ----- From: Ryan Mueller To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 6:06 AM Subject: Pietenpol-List: Question about short fuse with a Corvair I have a question regarding the need for the long fuselage when using a Corvair engine. Based on most of what I have read, the justification is that the long fuselage was developed to meet W&B requirements when using the Corvair/Continentals. What I fail to understand is how having a longer fuselage helps that issue, for this reason: lengthening the fuselage increases the moments for any weight that is moved aft. Therefore the structure of a long fuselage would have more wood farther aft of the datum than not, for lack of better phrasing. In addition, having the rear cockpit farther aft will only increase the arm of the pilot's weight. I don't see how moving more weight farther aft to compensate for a lighter engine up front computes. I understand the long fuse has more room inside. I was able to sit in the Last Original at Brodhead and had a generous amount of legroom, and my wife is shorter than I was, so I don't think the short fuse would cramp us. We would then be able to build a lighter aircraft. Finally, I would think at my weight (220) I would have to take less drastic measures to get a short fuse Corvair Piet to balance out than a long fuselage version. Any thoughts? Ryan href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com --------------------------------- ________________________________ Message 6 _____________________________________ Time: 08:08:11 AM PST US From: RAMPEYBOY@aol.com Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Maybe the intentions were multi point. Maybe the motor mount is lengthened to accommodate the lighter engine. While he was at it, he says to himself, hey some of these guys would like a little more leg room, so why not make the fuselage longer too.... So, the longer fuselage wasn't necessarily because of the engine change, but rather a actual revision of the designed features? Just a guess! ________________________________ Message 7 _____________________________________ Time: 08:32:29 AM PST US From: "Max Hegler" Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Does anyone have the firewall-to-tailpost length for both fuselages? Max ----- Original Message ----- From: RAMPEYBOY@aol.com To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 10:07 AM Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Maybe the intentions were multi point. Maybe the motor mount is lengthened to accommodate the lighter engine. While he was at it, he says to himself, hey some of these guys would like a little more leg room, so why not make the fuselage longer too.... So, the longer fuselage wasn't necessarily because of the engine change, but rather a actual revision of the designed features? Just a guess! ------------------------------------------------------------------------- ----- See what's n ________________________________ Message 8 _____________________________________ Time: 08:35:37 AM PST US From: "Max Hegler" Subject: Re: Pietenpol-List: Question about short fuse with a Corvair I thought lengthening the fuselage for the lighter engines was to offset the moment arm for control purposes. Lighter engines required longer engine mounts, thus resulting in longer "noses". This resulted in less control response with the shorter fuselage. Airplanes with engines that weigh as much as the Model "A" would not need any added length. Of course, I'm no aeroplane engineer! Take Care, Max ----- Original Message ----- From: Ryan Mueller To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 10:02 AM Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Regarding what you said about offsetting the heaver Corvair with more weight in the tail.... A Corvair engine is heavier than a Continental, yes. The long fuse was designed with the Corvair in mind, but since the Corvair is approximately 15 to 20 pounds lighter than Model A, why the need for the longer fuselage? As best I can figure, a Corvair with a short fuselage would therefore potentially be tail heavy (since there is a little less weight forward of the CG), which would be corrected by lengthening the engine mount (to extend the moment of the engine) and/or adjusting the cabane struts. If, in order to correct it, you then lengthen the fuselage and put more structure aft of the CG, in addition to moving the pilot slightly farther aft, this would only exacerbate an already tail heavy condition. Am I confused in my thinking? Ryan Roman Bukolt wrote: The Corvair engine weight about 230 lbs. The Continental weighs about 170 lbs. To keep the C.G. no further aft then 33% of the chord, you must offset the heavier Corvair with more weight in the the tail. My Piet was originally built long to accomodate a Corvair. Even then added weight was installed way back in the tail. Then the Corvair froze up and and was replaced with a Cont. A-65. When I bought the plane the C.G. was at 39%. Seriously tail heavy. Luckily I had Bill Rewey doing the landings and take offs when we flew the plane back to Madison, Wi. from Iowa. Since then I corrected the C.G. by installing a 30lb. 12v battery on the firewall. The C.G. is the balance point. All the weight ahead of the C.G. must equal all the weight aft of the C.G. The heavier engine in front requires more weight aft. A longer moment aft requires les weight than a short moment aft. And lightness is a good thing. Heaviness is not a good thing. The longer the moment, the less weight required. Roman Bukolt NX20795 ----- Original Message ----- From: Ryan Mueller To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 6:06 AM Subject: Pietenpol-List: Question about short fuse with a Corvair I have a question regarding the need for the long fuselage when using a Corvair engine. Based on most of what I have read, the justification is that the long fuselage was developed to meet W&B requirements when using the Corvair/Continentals. What I fail to understand is how having a longer fuselage helps that issue, for this reason: lengthening the fuselage increases the moments for any weight that is moved aft. Therefore the structure of a long fuselage would have more wood farther aft of the datum than not, for lack of better phrasing. In addition, having the rear cockpit farther aft will only increase the arm of the pilot's weight. I don't see how moving more weight farther aft to compensate for a lighter engine up front computes. I understand the long fuse has more room inside. I was able to sit in the Last Original at Brodhead and had a generous amount of legroom, and my wife is shorter than I was, so I don't think the short fuse would cramp us. We would then be able to build a lighter aircraft. Finally, I would think at my weight (220) I would have to take less drastic measures to get a short fuse Corvair Piet to balance out than a long fuselage version. Any thoughts? Ryan ________________________________ Message 9 _____________________________________ Time: 09:54:52 AM PST US From: Ryan Mueller Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Max, 172 and 3/8" for the "long" fuselage, 163" for the "short" fuselage from the Improved 1933 plans, and 161 and 1/4" for the "shortest" fuselage from the original F&G Manual plans. (Short and shortest figures derived from my addition of dimensions from the plans, the long fuselage distance is already calculated on the plans.) Ryan Max Hegler wrote: Does anyone have the firewall-to-tailpost length for both fuselages? Max ----- Original Message ----- From: RAMPEYBOY@aol.com To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 10:07 AM Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Maybe the intentions were multi point. Maybe the motor mount is lengthened to accommodate the lighter engine. While he was at it, he says to himself, hey some of these guys would like a little more leg room, so why not make the fuselage longer too.... So, the longer fuselage wasn't necessarily because of the engine change, but rather a actual revision of the designed features? Just a guess! --------------------------------- See what's n href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com --------------------------------- Need a vacation? Get great deals to amazing places on Yahoo! Travel. ________________________________ Message 10 ____________________________________ Time: 10:18:59 AM PST US From: Ryan Mueller Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Roman, I poked around Chris Tracy's site, to see pictures of your airplane (I couldn't recall what yours looked like...kinda like putting a face to a name). Looking at the rear cockpit shot from Brodhead 2007, I noticed that you have a steel tube fuselage. My conjecture would be that a Corvair powered steel tube fuselage Piet would be markedly different when it come to W&B than a wood fuselage. Because the steel tube is lighter than the wood, and all of the structure aft of the CG would weigh less, it makes sense that it would come out light in the tail. When you changed engines did you remove the weight that was added in the rear, in addition to having to add the battery up front? Roman Bukolt wrote: The Corvair engine weight about 230 lbs. The Continental weighs about 170 lbs. To keep the C.G. no further aft then 33% of the chord, you must offset the heavier Corvair with more weight in the the tail. My Piet was originally built long to accomodate a Corvair. Even then added weight was installed way back in the tail. Then the Corvair froze up and and was replaced with a Cont. A-65. When I bought the plane the C.G. was at 39%. Seriously tail heavy. Luckily I had Bill Rewey doing the landings and take offs when we flew the plane back to Madison, Wi. from Iowa. Since then I corrected the C.G. by installing a 30lb. 12v battery on the firewall. The C.G. is the balance point. All the weight ahead of the C.G. must equal all the weight aft of the C.G. The heavier engine in front requires more weight aft. A longer moment aft requires les weight than a short moment aft. And lightness is a good thing. Heaviness is not a good thing. The longer the moment, the less weight required. Roman Bukolt NX20795 ----- Original Message ----- From: Ryan Mueller To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 6:06 AM Subject: Pietenpol-List: Question about short fuse with a Corvair I have a question regarding the need for the long fuselage when using a Corvair engine. Based on most of what I have read, the justification is that the long fuselage was developed to meet W&B requirements when using the Corvair/Continentals. What I fail to understand is how having a longer fuselage helps that issue, for this reason: lengthening the fuselage increases the moments for any weight that is moved aft. Therefore the structure of a long fuselage would have more wood farther aft of the datum than not, for lack of better phrasing. In addition, having the rear cockpit farther aft will only increase the arm of the pilot's weight. I don't see how moving more weight farther aft to compensate for a lighter engine up front computes. I understand the long fuse has more room inside. I was able to sit in the Last Original at Brodhead and had a generous amount of legroom, and my wife is shorter than I was, so I don't think the short fuse would cramp us. We would then be able to build a lighter aircraft. Finally, I would think at my weight (220) I would have to take less drastic measures to get a short fuse Corvair Piet to balance out than a long fuselage version. Any thoughts? Ryan href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.matronics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com --------------------------------- Check out the hottest 2008 models today at Yahoo! Autos. ________________________________ Message 11 ____________________________________ Time: 10:38:26 AM PST US From: "Roman Bukolt" Subject: Re: Pietenpol-List: Question about short fuse with a Corvair When I bought the plane, it already had the Continental on it and the builder/previous owner had removed the weight. Yet it was still tail heavy. A steel tube fuselage is not lighter than a wood one. If anything it is heavier. Before I added the battery, the empty weight with the Cont. was 670 lbs. Bill Rewey's wood Piet weighs significantly less with the same engine. ----- Original Message ----- From: Ryan Mueller To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 12:18 PM Subject: Re: Pietenpol-List: Question about short fuse with a Corvair Roman, I poked around Chris Tracy's site, to see pictures of your airplane (I couldn't recall what yours looked like...kinda like putting a face to a name). Looking at the rear cockpit shot from Brodhead 2007, I noticed that you have a steel tube fuselage. My conjecture would be that a Corvair powered steel tube fuselage Piet would be markedly different when it come to W&B than a wood fuselage. Because the steel tube is lighter than the wood, and all of the structure aft of the CG would weigh less, it makes sense that it would come out light in the tail. When you changed engines did you remove the weight that was added in the rear, in addition to having to add the battery up front? Roman Bukolt wrote: The Corvair engine weight about 230 lbs. The Continental weighs about 170 lbs. To keep the C.G. no further aft then 33% of the chord, you must offset the heavier Corvair with more weight in the the tail. My Piet was originally built long to accomodate a Corvair. Even then added weight was installed way back in the tail. Then the Corvair froze up and and was replaced with a Cont. A-65. When I bought the plane the C.G. was at 39%. Seriously tail heavy. Luckily I had Bill Rewey doing the landings and take offs when we flew the plane back to Madison, Wi. from Iowa. Since then I corrected the C.G. by installing a 30lb. 12v battery on the firewall. The C.G. is the balance point. All the weight ahead of the C.G. must equal all the weight aft of the C.G. The heavier engine in front requires more weight aft. A longer moment aft requires les weight than a short moment aft. And lightness is a good thing. Heaviness is not a good thing. The longer the moment, the less weight required. Roman Bukolt NX20795 ----- Original Message ----- From: Ryan Mueller To: pietenpol-list@matronics.com Sent: Saturday, October 13, 2007 6:06 AM Subject: Pietenpol-List: Question about short fuse with a Corvair I have a question regarding the need for the long fuselage when using a Corvair engine. Based on most of what I have read, the justification is that the long fuselage was developed to meet W&B requirements when using the Corvair/Continentals. What I fail to understand is how having a longer fuselage helps that issue, for this reason: lengthening the fuselage increases the moments for any weight that is moved aft. Therefore the structure of a long fuselage would have more wood farther aft of the datum than not, for lack of better phrasing. In addition, having the rear cockpit farther aft will only increase the arm of the pilot's weight. I don't see how moving more weight farther aft to compensate for a lighter engine up front computes. I understand the long fuse has more room inside. I was able to sit in the Last Original at Brodhead and had a generous amount of legroom, and my wife is shorter than I was, so I don't think the short fuse would cramp us. We would then be able to build a lighter aircraft. Finally, I would think at my weight (220) I would have to take less drastic measures to get a short fuse Corvair Piet to balance out than a long fuselage version. Any thoughts? Ryan href="http://www.matronics.com/Navigator?Pietenpol-List">http://www.mat ronics.com/Navigator?Pietenpol-List href="http://forums.matronics.com">http://forums.matronics.com ">Check out the hottest 2008 models today at Yahoo! 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