---------------------------------------------------------- Zenith-List Digest Archive --- Total Messages Posted Mon 08/27/07: 27 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:27 AM - Re: somewhat off topic - Purchasing an incomplete homebuilt (cbaron66) 2. 07:37 AM - Re: Out-of-spec 601XL/Jabiru 3300 motor mount (Tim Juhl) 3. 07:39 AM - LRI probe (alex trent) 4. 07:50 AM - Re: Re: Out-of-spec 601XL/Jabiru 3300 motor mount (japhillipsga@aol.com) 5. 07:59 AM - Non-aviation question about fuel (octane and "knocking") (David Brooks) 6. 09:06 AM - Re: Non-aviation question about fuel (octane and "knocking") (Gig Giacona) 7. 09:34 AM - question about fuel related to aviation. (ZodieRocket) 8. 10:04 AM - Re: Zenith-List Digest: Purchasing an incomplete homebuilt () 9. 10:05 AM - N601BZ Fly's! (Bill Sewell) 10. 10:52 AM - Re: N601BZ Fly's! (LarryMcFarland) 11. 11:04 AM - Re: N601BZ Fly's! (wade jones) 12. 11:27 AM - Re: N601BZ Fly's! (John Marzulli) 13. 11:28 AM - Re: Non-aviation question about fuel (octane and "knocking") (Bryan Martin) 14. 11:42 AM - Re: N601BZ Fly's! () 15. 01:42 PM - Re:Non-aviation question about fuel (octane and "knocking") (MaxNr@aol.com) 16. 02:26 PM - Re: N601BZ Fly's! (eddies) 17. 02:39 PM - 601XL rear spar risk mitigation (Dr. Andrew Elliott) 18. 03:09 PM - Re: Non-aviation question about fuel (octane and "knockin g") (n801bh@netzero.com) 19. 03:12 PM - Re: N601BZ Fly's! (n801bh@netzero.com) 20. 04:03 PM - Re: N601BZ Fly's! (george may) 21. 04:38 PM - Re: N601BZ Fly's! (Matt & Jo) 22. 06:01 PM - Re: question about fuel related to aviation. (Ron Lendon) 23. 06:25 PM - Burger and a chat (4rcsimmons@comcast.net (Rich Simmons)) 24. 07:22 PM - Re: Cooling the cockpit (GLJSOJ1) 25. 07:34 PM - Re: N601BZ Fly's! (rgeese) 26. 07:42 PM - Re: chat (Falcon) 27. 10:04 PM - Re: N601BZ Fly's! (PatrickW) ________________________________ Message 1 _____________________________________ Time: 06:27:00 AM PST US Subject: Zenith-List: Re: somewhat off topic - Purchasing an incomplete homebuilt From: "cbaron66" Just a small note of correction: If the plane/parts meet the qualifications, you might get a repairmans certificate. Unless you complete the necessary schooling and or expeariance and pass all the written, oral and practical tests, you will never be an A&P 8) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131182#131182 ________________________________ Message 2 _____________________________________ Time: 07:37:32 AM PST US Subject: Zenith-List: Re: Out-of-spec 601XL/Jabiru 3300 motor mount From: "Tim Juhl" As I said, my mount is not ready to be installed - I must finish the fuselage first :-) Other than rigging up some kind of jig I'll have to wait until I get to that point. Tim Do not archive -------- ______________ CFII Champ L16A flying Zodiac XL - Jabiru 3300A Working on wings Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131190#131190 ________________________________ Message 3 _____________________________________ Time: 07:39:00 AM PST US From: alex trent Subject: Zenith-List: LRI probe I have made the LRI probe from the data available on the ch601.org site. The profile is not very streamlined and I wonder just how much I can radius it to give a more areodynamic profile with out effecting the accuracy. I am assuming that the 45 degree corner is important but how about the rest of it? alex t. > > > ________________________________ Message 4 _____________________________________ Time: 07:50:07 AM PST US Subject: Re: Zenith-List: Re: Out-of-spec 601XL/Jabiru 3300 motor mount From: japhillipsga@aol.com Tim, I happen to have an extra XL/Jab3300 engine mount. Depending on where you are you are welcome to use it. Call my cell at 478-731-9678. Bill of georgia -----Original Message----- From: Tim Juhl Sent: Mon, 27 Aug 2007 10:35 am Subject: Zenith-List: Re: Out-of-spec 601XL/Jabiru 3300 motor mount As I said, my mount is not ready to be installed - I must finish the fuselage first :-) Other than rigging up some kind of jig I'll have to wait until I get to that point. Tim Do not archive -------- ______________ CFII Champ L16A flying Zodiac XL - Jabiru 3300A Working on wings Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131190#131190 ________________________________________________________________________ Email and AIM finally together. You've gotta check out free AOL Mail! - http://mail.aol.com ________________________________ Message 5 _____________________________________ Time: 07:59:50 AM PST US From: "David Brooks" Subject: Zenith-List: Non-aviation question about fuel (octane and "knocking") I suppose this could be aviation related, especially for the 912ULS owners, but my cause for posting is not. I have a supercharged Miata that I have to feed 91+ octane gas or it will knock pretty severely when I put my foot in it, especially at high boost. I normally run around 5-7 pounds of boost around town and have no problems with knocking when I use 91. I run 13+ on the track and will only light up the knock sensor light under pretty extreme loads or on really hot days when the intercooler can't keep up. I have been buying 91 octane gas at a local station and lately I have been getting lots of knocking at the low boost levels, and I am not driving very hard. (I live in a town with 2500 people and three of them are full time cops. Not much chance for spirited driving.) My best guess was that I was starting to lose a valve seal or maybe I had some rings going bad and had carbon building up on the piston heads and that was causing detonation. But now I am not so sure. I filled up an almost empty tank out of town over the weekend and I haven't seen the knock light blink even once. I am now wondering about the gas at my local station. I did notice something interesting when looking at the pumps at my local station last time I was there. The pump only has two Hobbs-meter like counters at the top of the pump instead of three. I always thought those were total counters, one for each underground tank but this station sells three grades of gas. Could they be storing only two grades of gas and mixing 85 and 91 to get the 87 grade? Or worse, could they be selling 87 gas as 91? (I see one of the counters ticking away when I fill up with 91. I will put 87 in the truck next time it needs gas and I will see if both counters run at the same time.) A petro-chemist friend once tried to explain to me about gasoline molecule chain length and detonation, "cracking" during the refining process, and who knows what else. I am not a chemist (I don't even play one on TV) so I got lost pretty quickly. What I did take away from the conversation was that his opinion was that the lower grade octane gas (the shorter molecule chains?) would pre-detonate under compression even if mixed with the high octane gas causing the whole mix to go up. (It was also his strongly expressed opinion that "octane boosters" were pretty useless as well.) I want to make it clear that I am not sure I understand what is going on in the cylinder when "knocking" occurs, so I am starting at a bit of a disadvantage on this whole issue. So I guess my questions to this (incredibly) knowledgeable group are these: - Does mixing different octane fuel "average" the effective octane of each grade? - How can a regular schmoe like me find out of they are selling 89 octane gas as 91? I am pretty sure that asking isn't going to get me very far. - Could there be additives in the gas that might encourage knocking? Would the 10% Ethanol gas cause more knocking than the undiluted fuel? - What is really going on when the engine "knocks"? (The sensor replaces one of the engine mount bolts on the engine side. It looks like an epoxy filled hollow bolt with a wire lead coming out the end. That wire runs back to the after market ECU. Is this sensor really just a microphone listening for "knocks"? Can it be that simple?) - What (if anything) is the difference between "knock" and "pre-detonation"? I hear both terms used and have always wondered if they meant something different. - What do you 912ULS owners do when you can't find 91 octane gas? Is there an octane booster that you like? Do they even work at all? - What are the minimum octane requirements for the non-912ULS engine options like the Jabiru 3300? (I am planning on building a 701 one of these fine days. Honest.) Please forgive the posting of a not totally aviation related question to this board, but the depth of knowledge here is astounding and I figured this was about as good a place to go for help as I was likely to find. Asking technical questions on most of the auto lists usually gets responses like "Buy a real car". Besides, if I put wings on this car I sometimes think it would take to the air! Too bad it is too heavy to qualify as an E-LSA plane. The power to weight ratio is about right... Thanks in advance, and feel free to contact me directly if you don't want to clutter up the list with this topic. Dave Please do not archive ________________________________ Message 6 _____________________________________ Time: 09:06:28 AM PST US Subject: Zenith-List: Re: Non-aviation question about fuel (octane and "knocking") From: "Gig Giacona" I can really on help on one of your questions. Does mixing different octane fuel "average" the effective octane of each grade? Yes, when you go to a station that has 3 grades look around there are only, in most cases, only two tanks. This is because to make the middle grade the pump mixes premium and unleaded. Have you tried a full tank from another station that uses a different distributor? If the knocking goes away when you do the problem is with their gas if not it is with your car. -------- W.R. "Gig" Giacona 601XL Under Construction See my progress at www.peoamerica.net/N601WR Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131201#131201 ________________________________ Message 7 _____________________________________ Time: 09:34:39 AM PST US From: "ZodieRocket" Subject: Zenith-List: question about fuel related to aviation. David , I tried to find the transport Canada letter explaining the Octane loss of Mogas. From memory after a week 95 = 94 two weeks 95= 92 3 weeks 95=90 4 weeks 95 = 87 5 weeks 95 = 84 3 mos ' use only to start fires And so on. Plastic containers lose octane a lot faster then steel kept in dark and cold. Short of it, is simple, after 2 weeks never add this gas to your plane, after 3 mos never use this gas in your lawnmower as mogas separates and creates varnish. IF your going to store your fuel for more then 3 mos for your car or lawnmower add fuel stabilizer. Then you are good for a year, give or take a month. Also be aware in northern climates and in Canada Especially we have 4 different blends of fuel depending on the season. EACH BLEND WILL AFFECT CARB ICING TIMES. In short , only buy your gas from a busy station. Never store for more then 3 mos without action. Never trust that the high grade of fuel you just bought at a gas station is new mix and fresh. Mark Townsend Can-Zac Aviation Ltd. HYPERLINK "mailto:president@can-zacaviation.com"president@can-zacaviation.com HYPERLINK "http://www.can-zacaviation.com/"www.can-zacaviation.com -----Original Message----- From: owner-zenith-list-server@matronics.com [mailto:owner-zenith-list-server@matronics.com] On Behalf Of David Brooks Sent: Monday, August 27, 2007 10:59 AM Subject: Zenith-List: Non-aviation question about fuel (octane and "knocking") I suppose this could be aviation related, especially for the 912ULS owners, but my cause for posting is not. I have a supercharged Miata that I have to feed 91+ octane gas or it will knock pretty severely when I put my foot in it, especially at high boost. I normally run around 5-7 pounds of boost around town and have no problems with knocking when I use 91. I run 13+ on the track and will only light up the knock sensor light under pretty extreme loads or on really hot days when the intercooler can't keep up. I have been buying 91 octane gas at a local station and lately I have been getting lots of knocking at the low boost levels, and I am not driving very hard. (I live in a town with 2500 people and three of them are full time cops. Not much chance for spirited driving.) My best guess was that I was starting to lose a valve seal or maybe I had some rings going bad and had carbon building up on the piston heads and that was causing detonation. But now I am not so sure. I filled up an almost empty tank out of town over the weekend and I haven't seen the knock light blink even once. I am now wondering about the gas at my local station. I did notice something interesting when looking at the pumps at my local station last time I was there. The pump only has two Hobbs-meter like counters at the top of the pump instead of three. I always thought those were total counters, one for each underground tank but this station sells three grades of gas. Could they be storing only two grades of gas and mixing 85 and 91 to get the 87 grade? Or worse, could they be selling 87 gas as 91? (I see one of the counters ticking away when I fill up with 91. I will put 87 in the truck next time it needs gas and I will see if both counters run at the same time.) A petro-chemist friend once tried to explain to me about gasoline molecule chain length and detonation, "cracking" during the refining process, and who knows what else. I am not a chemist (I don't even play one on TV) so I got lost pretty quickly. What I did take away from the conversation was that his opinion was that the lower grade octane gas (the shorter molecule chains?) would pre-detonate under compression even if mixed with the high octane gas causing the whole mix to go up. (It was also his strongly expressed opinion that "octane boosters" were pretty useless as well.) I want to make it clear that I am not sure I understand what is going on in the cylinder when "knocking" occurs, so I am starting at a bit of a disadvantage on this whole issue. So I guess my questions to this (incredibly) knowledgeable group are these: * Does mixing different octane fuel "average" the effective octane of each grade? * How can a regular schmoe like me find out of they are selling 89 octane gas as 91? I am pretty sure that asking isn't going to get me very far. * Could there be additives in the gas that might encourage knocking? Would the 10% Ethanol gas cause more knocking than the undiluted fuel? * What is really going on when the engine "knocks"? (The sensor replaces one of the engine mount bolts on the engine side. It looks like an epoxy filled hollow bolt with a wire lead coming out the end. That wire runs back to the after market ECU. Is this sensor really just a microphone listening for "knocks"? Can it be that simple?) * What (if anything) is the difference between "knock" and "pre-detonation"? I hear both terms used and have always wondered if they meant something different. * What do you 912ULS owners do when you can't find 91 octane gas? Is there an octane booster that you like? Do they even work at all? * What are the minimum octane requirements for the non-912ULS engine options like the Jabiru 3300? (I am planning on building a 701 one of these fine days. Honest.) Please forgive the posting of a not totally aviation related question to this board, but the depth of knowledge here is astounding and I figured this was about as good a place to go for help as I was likely to find. Asking technical questions on most of the auto lists usually gets responses like "Buy a real car". Besides, if I put wings on this car I sometimes think it would take to the air! Too bad it is too heavy to qualify as an E-LSA plane. The power to weight ratio is about right... Thanks in advance, and feel free to contact me directly if you don't want to clutter up the list with this topic. Dave Please do not archive "http://www.matronics.com/Navigator?Zenith-List"http://www.matronics.com /Navigator?Zenith-List "http://forums.matronics.com"http://forums.matronics.com 8/26/2007 9:34 PM 8/26/2007 9:34 PM ________________________________ Message 8 _____________________________________ Time: 10:04:56 AM PST US Subject: Zenith-List: RE: Zenith-List Digest: Purchasing an incomplete homebuilt From: Bob, The subject was recently addressed, I believe it was in KitPlanes. To meet the rule the plane must be built 51% by amateurs. You will need to have documentation of the previous builders. If you complete the project you can apply for the Repairman certificate. Craig S. N601XS, 601xl lyc 0-235 I looked at CH601HD project, recently advertised here, and have a couple of questions about purchasing a work in progress: 1 - Is it possible to be the A&P for a purchased project? I seem to recall that this honor can be bestowed on the original builder and I wonder if it is applicable to someone who finishes a project. 2 - What must be done to satisfy the FAA that you meet the 51% rule? Thx Bob Percival ----------------------------------------- ************************************************** This e-mail and any of its attachments may contain Exelon Corporation proprietary information, which is privileged, confidential, or subject to copyright belonging to the Exelon Corporation family of Companies. This e-mail is intended solely for the use of the individual or entity to which it is addressed. If you are not the intended recipient of this e-mail, you are hereby notified that any dissemination, distribution, copying, or action taken in relation to the contents of and attachments to this e-mail is strictly prohibited and may be unlawful. If you have received this e-mail in error, please notify the sender immediately and permanently delete the original and any copy of this e-mail and any printout. Thank You. ************************************************** ________________________________ Message 9 _____________________________________ Time: 10:05:09 AM PST US From: "Bill Sewell" Subject: Zenith-List: N601BZ Fly's! Today, August 27, 2007, at 8:56AM EDT N601BZ flew for the first time. The flight was unintentional, occurring during a high speed taxi test. I had the stick full back as is typical when taxing a conventional gear aircraft and as the aircraft accelerated past 40MPH and approached 50MPH, just as I was about to bring the tail up, the right wheel broke ground. I moved the stick to the right and the left wheel came up and we were flying. I moved the stick to lower the nose into a gentle climb attitude and added right trim to bring the stick back to neutral. I then trimmed the nose up to continue the climb at around 90 MPH, when I had a chance to look, and was at pattern altitude before I knew it. Since the there were clouds at about 2000 feet and since I hadn't intended to fly in the first place, I decided to make one circuit of the pattern and attempt to put the airplane back on the runway at the first opportunity. I made a gentle left turn to cross wind and another to down wind. Once on down wind, I reduced power to 2000 and added a bit more nose up trim. Once past the end of the runway I reduced power to 1500 and began a smooth gradual descent. Another gentle left turn to base and one more to final and before I knew it I was over the end of the runway. I pulled power back to idle as I flared and the propeller stopped just a second before I made a soft 3 point touch down. I rolled out and slowed down and restarted the engine with the starter. My first flight was over and it probably lasted all of 6 minutes. So this is what I learned. First, the TD will take off in a 3 point attitude very easily. The 601XL accelerates very quickly once the throttle is fully open. I had heard about the left wing being heavy and needing right trim from other first flight reports so there was no surprise there. I'm not sure why the propeller stopped over the runway in the flair, the ground idle speed is set to 850 and hasn't been a problem. I realized after landing that I had forgotten to pull carb heat and it was a humid so I suppose there might have been some carb ice but I'm not convinced of that. I will download the EMS data and see if it contains any clue. Even though my first flight was very short, my impression of the 601XL's flight characteristics are that it is very much like a Citabria or even a Cessna and I felt right at home flying it. The landing and taxi characteristics are also very similar to the Citabria that I have done most of my tail wheel flying in. I will be posting some video to my web site in the near future. Just want to thank Zenith Aircraft for a great design and all the other builders that have helped me out. And of course to thank my wife for supporting my hobby and for filming my "high speed taxi tests." Bill Sewell N601BZ ________________________________ Message 10 ____________________________________ Time: 10:52:37 AM PST US From: LarryMcFarland Subject: Re: Zenith-List: N601BZ Fly's! Congratulations Bill, This is one of life's best adventures. Pleased you made it in one piece. Do continue to fly safe, Larry McFarland 601HDS at www.macsmachine.com do not archive. Bill Sewell wrote: > > Today, August 27, 2007, at 8:56AM EDT N601BZ flew for the first time. > > Just want to thank Zenith Aircraft for a great design and all the > other builders that have helped me out. And of course to thank my > wife for supporting my hobby and for filming my "high speed taxi tests." > > > > Bill Sewell > > N601BZ > ________________________________ Message 11 ____________________________________ Time: 11:04:16 AM PST US From: "wade jones" Subject: Re: Zenith-List: N601BZ Fly's! Congratulations Bill ,you have built a beautiful aircraft and did well on your first flight .I have seen this happen before with high speed taxing and it is nice when your plane is prepared for flight even when it is not your intention .Thanks for the help you have given me and as always be safe and enjoy your new toy . Wade Jones South Texas 601XL plans building Cont. 0200 ----- Original Message ----- From: Bill Sewell To: zenith-list@matronics.com ; Zenith AC Support Sent: Monday, August 27, 2007 12:04 PM Subject: Zenith-List: N601BZ Fly's! Today, August 27, 2007, at 8:56AM EDT N601BZ flew for the first time. The flight was unintentional, occurring during a high speed taxi test. I had the stick full back as is typical when taxing a conventional gear aircraft and as the aircraft accelerated past 40MPH and approached 50MPH, just as I was about to bring the tail up, the right wheel broke ground. I moved the stick to the right and the left wheel came up and we were flying. I moved the stick to lower the nose into a gentle climb attitude and added right trim to bring the stick back to neutral. I then trimmed the nose up to continue the climb at around 90 MPH, when I had a chance to look, and was at pattern altitude before I knew it. Since the there were clouds at about 2000 feet and since I hadn't intended to fly in the first place, I decided to make one circuit of the pattern and attempt to put the airplane back on the runway at the first opportunity. I made a gentle left turn to cross wind and another to down wind. Once on down wind, I reduced power to 2000 and added a bit more nose up trim. Once past the end of the runway I reduced power to 1500 and began a smooth gradual descent. Another gentle left turn to base and one more to final and before I knew it I was over the end of the runway. I pulled power back to idle as I flared and the propeller stopped just a second before I made a soft 3 point touch down. I rolled out and slowed down and restarted the engine with the starter. My first flight was over and it probably lasted all of 6 minutes. So this is what I learned. First, the TD will take off in a 3 point attitude very easily. The 601XL accelerates very quickly once the throttle is fully open. I had heard about the left wing being heavy and needing right trim from other first flight reports so there was no surprise there. I'm not sure why the propeller stopped over the runway in the flair, the ground idle speed is set to 850 and hasn't been a problem. I realized after landing that I had forgotten to pull carb heat and it was a humid so I suppose there might have been some carb ice but I'm not convinced of that. I will download the EMS data and see if it contains any clue. Even though my first flight was very short, my impression of the 601XL's flight characteristics are that it is very much like a Citabria or even a Cessna and I felt right at home flying it. The landing and taxi characteristics are also very similar to the Citabria that I have done most of my tail wheel flying in. I will be posting some video to my web site in the near future. Just want to thank Zenith Aircraft for a great design and all the other builders that have helped me out. And of course to thank my wife for supporting my hobby and for filming my "high speed taxi tests." Bill Sewell N601BZ ________________________________ Message 12 ____________________________________ Time: 11:27:55 AM PST US From: "John Marzulli" Subject: Re: Zenith-List: N601BZ Fly's! Congrats and good luck tracking down the engine gremlins. What engine are you using? -John in Seattle On 8/27/07, Bill Sewell wrote: > > Today, August 27, 2007, at 8:56AM EDT N601BZ flew for the first time. The > flight was unintentional, occurring during a high speed taxi test. I had > the stick full back as is typical when taxing a conventional gear aircraft > and as the aircraft accelerated past 40MPH and approached 50MPH, just as I > was about to bring the tail up, the right wheel broke ground. I moved > the stick to the right and the left wheel came up and we were flying. I > moved the stick to lower the nose into a gentle climb attitude and added > right trim to bring the stick back to neutral. I then trimmed the nose > up to continue the climb at around 90 MPH, when I had a chance to look, and > was at pattern altitude before I knew it. Since the there were clouds at > about 2000 feet and since I hadn't intended to fly in the first place, I > decided to make one circuit of the pattern and attempt to put the airplane > back on the runway at the first opportunity. I made a gentle left turn > to cross wind and another to down wind. Once on down wind, I reduced > power to 2000 and added a bit more nose up trim. Once past the end of > the runway I reduced power to 1500 and began a smooth gradual descent. Another > gentle left turn to base and one more to final and before I knew it I was > over the end of the runway. I pulled power back to idle as I flared and > the propeller stopped just a second before I made a soft 3 point touch down. > I rolled out and slowed down and restarted the engine with the starter. My > first flight was over and it probably lasted all of 6 minutes. > > > So this is what I learned. First, the TD will take off in a 3 point > attitude very easily. The 601XL accelerates very quickly once the > throttle is fully open. I had heard about the left wing being heavy and > needing right trim from other first flight reports so there was no surprise > there. I'm not sure why the propeller stopped over the runway in the > flair, the ground idle speed is set to 850 and hasn't been a problem. I > realized after landing that I had forgotten to pull carb heat and it was a > humid so I suppose there might have been some carb ice but I'm not convinced > of that. I will download the EMS data and see if it contains any clue. > > > Even though my first flight was very short, my impression of the 601XL's > flight characteristics are that it is very much like a Citabria or even a > Cessna and I felt right at home flying it. The landing and taxi > characteristics are also very similar to the Citabria that I have done most > of my tail wheel flying in. > > > I will be posting some video to my web site in the near future. > > > Just want to thank Zenith Aircraft for a great design and all the other > builders that have helped me out. And of course to thank my wife for > supporting my hobby and for filming my "high speed taxi tests." > > > Bill Sewell > > N601BZ > > * > > > * > > -- John Marzulli http://701Builder.blogspot.com/ "Flying a plane is no different than riding a bicycle... it's just a lot harder to put baseball cards in the spokes. -Airplane The Movie ________________________________ Message 13 ____________________________________ Time: 11:28:10 AM PST US From: Bryan Martin Subject: Re: Zenith-List: Non-aviation question about fuel (octane and "knocking") Nearly all fuel stations that sell multiple grades of gasoline only have two tanks, one for regular grade and one for premium grade. To get mid grade, they just mix the regular and premium in the proper proportion to get the mid grade anti knock rating. On Aug 27, 2007, at 10:59 AM, David Brooks wrote: > I suppose this could be aviation related, especially for the 912ULS > owners, but my cause for posting is not. > > I have a supercharged Miata that I have to feed 91+ octane gas or > it will knock pretty severely when I put my foot in it, .... > > > So I guess my questions to this (incredibly) knowledgeable group > are these: > Does mixing different octane fuel "average" the effective octane of > each grade? Yes ,mixing one gallon of 91 octane gas with two gallons of 85 octane will give you three gallons of 87 octane. > How can a regular schmoe like me find out of they are selling 89 > octane gas as 91? I am pretty sure that asking isn't going to get > me very far. It sounds like someone dumped some regular fuel in the premium tank. Unfortunately, there is no simple way to test gasoline for the proper octane level. You'll need to find out who does the inspections of that station and complain. > > Could there be additives in the gas that might encourage knocking? > Would the 10% Ethanol gas cause more knocking than the undiluted fuel? Because of the alcohol, a small amount of water will dissolve in gasoline containing alcohol. If too much water is mixed with gasohol, the water will settle out of the mixture instead, taking all the alcohol with it. If there was a large amount of water settled out in the bottom of the tank when gasoline containing alcohol was added to the tank, it's possible that the alcohol ended up dissolved in the water at the bottom of the tank. Since the alcohol acts as an octane booster, this would result in a reduction in the octane rating of the gasoline floating on top of the water in the tank. > What is really going on when the engine "knocks"? (The sensor > replaces one of the engine mount bolts on the engine side. It > looks like an epoxy filled hollow bolt with a wire lead coming out > the end. That wire runs back to the after market ECU. Is this > sensor really just a microphone listening for "knocks"? Can it be > that simple?) > That's about right. > What (if anything) is the difference between "knock" and "pre- > detonation"? I hear both terms used and have always wondered if > they meant something different. Knock is caused by detonation (not pre-detonation). Pre-ignition is something entirely different. see: http://www.hrd-performance.com/13.html or: http://www.northernstar.ab.ca/ftp/images/pres/BrentPowers.pdf You must live in an high altitude area if the local stations sell 85, 87 and 91 octane fuel. In the low lands, the standard grades are 87, 89 and 93 octane. -- Bryan Martin N61BM, CH 601 XL, RAM Subaru, Stratus redrive. do not archive. ________________________________ Message 14 ____________________________________ Time: 11:42:24 AM PST US From: Subject: Re: Zenith-List: N601BZ Fly's! First, my congratulations on a successful (although "unintentional") first flight. That had to be a thrill to remember and I'm glad it went so smoothly for you. Second, some recent posts have urged setting the idle rpm to 1,000 until the engine has run enough (25 - 35 hrs?) to loosen up a bit. I can't speak to that since mine isn't flying yet. Third, I have to say that I find the "oops factor" somewhat suspicious in your story. Hell, call me a cynic, but I wouldn't expect the general public to buy that story at face value. I detect a touch of "Damn the torpedoes.... full speed ahead" in the account. But hey, it's your story so stick to it. It has been run up the flagpole and some will salute it even if there's a hint of N601BS rather than N601BZ in it. '-) Dred PS: Did you buy the kit then tell your wife, "Honey, it followed me home. Can we keep it?" As you were. Carry on. Do Not Archive ________________________________ Message 15 ____________________________________ Time: 01:42:52 PM PST US From: MaxNr@aol.com Subject: Zenith-List: Re:Non-aviation question about fuel (octane and "knocking") You can find more info about autofuel than you want to know at Peterson's auto fuel site (http://www.autofuelstc.com). He sells auto fuel stc's for certified A/C and has several informative links including a page for homebuilders. Regarding blending fuels: I recall one of the instructors discussing just that in the classroom in military flight school back in the last half of the 20th century. I was told that if you blended 91 and 115 octane in equal proportions, you would wind up with something around 95 octane. We were learning about the R1300 and R1340 and we were running on 115/145. 91/96 was approved. Caution. This info may have been updated since. My Lycoming O-235 has a compression ratio of 6.75:1 and its just possible that it may run OK on fuel from any third world country. Vapor lock would be the big thing to worry about as I like to fly high on cross country. Check the web site above for details. If "knocking" or detonation happens, it will make your CHT go bananas. Remember that alky rots both your brain and your carburetor. Do not archive Bob - Pace,FL XL/Lyc ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour ________________________________ Message 16 ____________________________________ Time: 02:26:28 PM PST US Subject: Zenith-List: Re: N601BZ Fly's! From: "eddies" A big congratulations Bill, looking forward to seeing your flight video's on your website Eddie Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131237#131237 ________________________________ Message 17 ____________________________________ Time: 02:39:50 PM PST US From: "Dr. Andrew Elliott" Subject: Zenith-List: 601XL rear spar risk mitigation Gang: I appreciate all the feedback I have gotten on my idea to mitigate the risk of rear spar failures by adding a small strap to the lower spar flange in the area of the aileron pushrod hole. This was discussed in detail at http://members.cox.net/n601ge/drawings/rearspar.html Many people have other ideas, which is why it's called "experimental" aviation! I would like to add some notes: [1] It should be straightforward to inspect the strap doubler on a regular basis for working rivets or cracks. So an additional good characteristic of this type of risk mitigation is that you can use it to get some real data on the hypothetical problem. If people install the strap and report no damage over time (50 hour intervals?), then either there was no problem there or the minimalist fix worked like a charm. If people later report that they are finding evidence of strap fatigue, then we have identified a "real" problem and can work out a "real" fix. [1a] If you install such a strap, you should note it in your builder's log and consider putting an inspection item in your annual checklist - "Visually inspect strap doublers on rear spar lower flange in area of aileron pushrod for any evidence of cracks, fatigue or working rivets." Over the years, as evidence builds, you will gain (or lose) confidence in the design and/or strap. [3] It was brought up to me by one respondent that for scratch builders, there is an option to use a 2-piece rear spar, and that this design has a larger, heavy-duty splice in the same area. If people with that design built and flying can inspect the doubler and report its apparent condition, those would be additional data points. FWIW, Andy Elliott, Mesa, AZ N601GE (reserved) 601XL/TD/QB, Corvair, building... ________________________________ Message 18 ____________________________________ Time: 03:09:44 PM PST US From: "n801bh@netzero.com" Subject: Re: Zenith-List: Non-aviation question about fuel (octane and "knockin g") You can probably bet the gas station is selling low octane in the high o ctane pump. They know it takes some pretty complex equiptment to test th e true octane in gas and are gambling no one is going to complain. Even if someone did, the testers sent out by the state to comfirm the given o ctane rating are probably not going to get an accurate number either bec ause of various factors beyond their control. Good luck..... do not archive Ben Haas N801BH www.haaspowerair.com -- "David Brooks" wrote: I suppose this could be aviation related, especially for the 912ULS owne rs, but my cause for posting is not. I have a supercharged Miata that I have to feed 91+ octane gas or it wil l knock pretty severely when I put my foot in it, especially at high boo st. I normally run around 5-7 pounds of boost around town and have no pr oblems with knocking when I use 91. I run 13+ on the track and will onl y light up the knock sensor light under pretty extreme loads or on reall y hot days when the intercooler can't keep up. I have been buying 91 octane gas at a local station and lately I have be en getting lots of knocking at the low boost levels, and I am not drivin g very hard. (I live in a town with 2500 people and three of them are f ull time cops. Not much chance for spirited driving.) My best guess wa s that I was starting to lose a valve seal or maybe I had some rings goi ng bad and had carbon building up on the piston heads and that was causi ng detonation. But now I am not so sure. I filled up an almost empty t ank out of town over the weekend and I haven't seen the knock light blin k even once. I am now wondering about the gas at my local station. I did notice something interesting when looking at the pumps at my local station last time I was there. The pump only has two Hobbs-meter like counters at the top of the pump instead of three. I always thought thos e were total counters, one for each underground tank but this station se lls three grades of gas. Could they be storing only two grades of gas a nd mixing 85 and 91 to get the 87 grade? Or worse, could they be sellin g 87 gas as 91? (I see one of the counters ticking away when I fill up with 91. I will put 87 in the truck next time it needs gas and I will s ee if both counters run at the same time.) A petro-chemist friend once tried to explain to me about gasoline molecu le chain length and detonation, "cracking" during the refining process, and who knows what else. I am not a chemist (I don't even play one on T V) so I got lost pretty quickly. What I did take away from the conversa tion was that his opinion was that the lower grade octane gas (the short er molecule chains?) would pre-detonate under compression even if mixed with the high octane gas causing the whole mix to go up. (It was also h is strongly expressed opinion that "octane boosters" were pretty useless as well.) I want to make it clear that I am not sure I understand what is going on in the cylinder when "knocking" occurs, so I am starting at a bit of a disadvantage on this whole issue. So I guess my questions to this (incredibly) knowledgeable group are the se: Does mixing different octane fuel "average" the effective octane of each grade? How can a regular schmoe like me find out of they are selling 89 octane gas as 91? I am pretty sure that asking isn't going to get me very far. Could there be additives in the gas that might encourage knocking? Woul d the 10% Ethanol gas cause more knocking than the undiluted fuel? What is really going on when the engine "knocks"? (The sensor replaces one of the engine mount bolts on the engine side. It looks like an epox y filled hollow bolt with a wire lead coming out the end. That wire run s back to the after market ECU. Is this sensor really just a microphone listening for "knocks"? Can it be that simple?) What (if anything) is the difference between "knock" and "pre-detonation "? I hear both terms used and have always wondered if they meant someth ing different. What do you 912ULS owners do when you can't find 91 octane gas? Is ther e an octane booster that you like? Do they even work at all? What are the minimum octane requirements for the non-912ULS engine optio ns like the Jabiru 3300? (I am planning on building a 701 one of these fine days. Honest.) Please forgive the posting of a not totally aviation related question to this board, but the depth of knowledge here is astounding and I figured this was about as good a place to go for help as I was likely to find. Asking technical questions on most of the auto lists usually gets respo nses like "Buy a real car". Besides, if I put wings on this car I somet imes think it would take to the air! Too bad it is too heavy to qualify as an E-LSA plane. The power to weight ratio is about right... Thanks in advance, and feel free to contact me directly if you don't wan t to clutter up the list with this topic. Dave Please do not archive ======================== ======================== ======================== ======================== ======================== ________________________________ Message 19 ____________________________________ Time: 03:12:43 PM PST US From: "n801bh@netzero.com" Subject: Re: Zenith-List: N601BZ Fly's! A BIG congrats to you,,,, I bet you still have that silly grin on your f ace too.... do not archive Ben Haas N801BH www.haaspowerair.com -- "Bill Sewell" wrote: Today, August 27, 2007, at 8:56AM EDT N601BZ flew for the first time. T he flight was unintentional, occurring during a high speed taxi test. I had the stick full back as is typical when taxing a conventional gear aircraft and as the aircraft accelerated past 40MPH and approached 50MPH , just as I was about to bring the tail up, the right wheel broke ground . I moved the stick to the right and the left wheel came up and we wer e flying. I moved the stick to lower the nose into a gentle climb attit ude and added right trim to bring the stick back to neutral. I then tr immed the nose up to continue the climb at around 90 MPH, when I had a c hance to look, and was at pattern altitude before I knew it. Since the there were clouds at about 2000 feet and since I hadn't intended to fly in the first place, I decided to make one circuit of the pattern and att empt to put the airplane back on the runway at the first opportunity. I made a gentle left turn to cross wind and another to down wind. Once on down wind, I reduced power to 2000 and added a bit more nose up trim. Once past the end of the runway I reduced power to 1500 and began a s mooth gradual descent. Another gentle left turn to base and one more to final and before I knew it I was over the end of the runway. I pulled power back to idle as I flared and the propeller stopped just a second before I made a soft 3 point touch down. I rolled out and slowed down a nd restarted the engine with the starter. My first flight was over and it probably lasted all of 6 minutes. So this is what I learned. First, the TD will take off in a 3 point att itude very easily. The 601XL accelerates very quickly once the throttl e is fully open. I had heard about the left wing being heavy and needin g right trim from other first flight reports so there was no surprise th ere. I'm not sure why the propeller stopped over the runway in the fla ir, the ground idle speed is set to 850 and hasn't been a problem. I re alized after landing that I had forgotten to pull carb heat and it was a humid so I suppose there might have been some carb ice but I'm not conv inced of that. I will download the EMS data and see if it contains any clue. Even though my first flight was very short, my impression of the 601XL's flight characteristics are that it is very much like a Citabria or even a Cessna and I felt right at home flying it. The landing and taxi cha racteristics are also very similar to the Citabria that I have done most of my tail wheel flying in. I will be posting some video to my web site in the near future. Just want to thank Zenith Aircraft for a great design and all the other builders that have helped me out. And of course to thank my wife for su pporting my hobby and for filming my "high speed taxi tests." Bill Sewell N601BZ ======================== ======================== ======================== ======================== ======================== ________________________________ Message 20 ____________________________________ Time: 04:03:04 PM PST US From: "george may" Subject: RE: Zenith-List: N601BZ Fly's! Bill Congradulations!! The fun begins------- George May 601XL 912s 147hrs >From: "Bill Sewell" >To: zenith-list@matronics.com, "Zenith AC Support" >Subject: Zenith-List: N601BZ Fly's! >Date: Mon, 27 Aug 2007 13:04:46 -0400 > >Today, August 27, 2007, at 8:56AM EDT N601BZ flew for the first time. The >flight was unintentional, occurring during a high speed taxi test. I had >the stick full back as is typical when taxing a conventional gear aircraft >and as the aircraft accelerated past 40MPH and approached 50MPH, just as I >was about to bring the tail up, the right wheel broke ground. I moved the >stick to the right and the left wheel came up and we were flying. I moved >the stick to lower the nose into a gentle climb attitude and added right >trim to bring the stick back to neutral. I then trimmed the nose up to >continue the climb at around 90 MPH, when I had a chance to look, and was >at >pattern altitude before I knew it. Since the there were clouds at about >2000 feet and since I hadn't intended to fly in the first place, I decided >to make one circuit of the pattern and attempt to put the airplane back on >the runway at the first opportunity. I made a gentle left turn to cross >wind and another to down wind. Once on down wind, I reduced power to 2000 >and added a bit more nose up trim. Once past the end of the runway I >reduced power to 1500 and began a smooth gradual descent. Another gentle >left turn to base and one more to final and before I knew it I was over the >end of the runway. I pulled power back to idle as I flared and the >propeller stopped just a second before I made a soft 3 point touch down. I >rolled out and slowed down and restarted the engine with the starter. My >first flight was over and it probably lasted all of 6 minutes. > > >So this is what I learned. First, the TD will take off in a 3 point >attitude very easily. The 601XL accelerates very quickly once the throttle >is fully open. I had heard about the left wing being heavy and needing >right trim from other first flight reports so there was no surprise there. >I'm >not sure why the propeller stopped over the runway in the flair, the ground >idle speed is set to 850 and hasn't been a problem. I realized after >landing that I had forgotten to pull carb heat and it was a humid so I >suppose there might have been some carb ice but I'm not convinced of that. >I >will download the EMS data and see if it contains any clue. > > >Even though my first flight was very short, my impression of the 601XL's >flight characteristics are that it is very much like a Citabria or even a >Cessna and I felt right at home flying it. The landing and taxi >characteristics are also very similar to the Citabria that I have done most >of my tail wheel flying in. > > >I will be posting some video to my web site in the near future. > > >Just want to thank Zenith Aircraft for a great design and all the other >builders that have helped me out. And of course to thank my wife for >supporting my hobby and for filming my "high speed taxi tests." > > >Bill Sewell > >N601BZ _________________________________________________________________ Booking a flight? Know when to buy with airfare predictions on MSN Travel. http://travel.msn.com/Articles/aboutfarecast.aspx&ocid=T001MSN25A07001 ________________________________ Message 21 ____________________________________ Time: 04:38:17 PM PST US From: "Matt & Jo" Subject: Re: Zenith-List: N601BZ Fly's! Congratulations Bill, I have been following your progress on your website and it has really helped when I run into problems. Great News. Keep Safe Matt Archer www.zodiacxl.com ----- Original Message ----- From: Bill Sewell To: zenith-list@matronics.com ; Zenith AC Support Sent: Monday, August 27, 2007 12:04 PM Subject: Zenith-List: N601BZ Fly's! Today, August 27, 2007, at 8:56AM EDT N601BZ flew for the first time. The flight was unintentional, occurring during a high speed taxi test. I had the stick full back as is typical when taxing a conventional gear aircraft and as the aircraft accelerated past 40MPH and approached 50MPH, just as I was about to bring the tail up, the right wheel ________________________________ Message 22 ____________________________________ Time: 06:01:23 PM PST US Subject: Zenith-List: Re: question about fuel related to aviation. From: "Ron Lendon" Boy Mark, that blue stuff looks better all the time. :D -------- Ron Lendon, Clinton Township, MI Corvair Zodiac XL, ScrapBuilder ;-) http://www.mykitlog.com/rlendon Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131269#131269 ________________________________ Message 23 ____________________________________ Time: 06:25:22 PM PST US From: 4rcsimmons@comcast.net (Rich Simmons) Subject: Zenith-List: Burger and a chat Hey List, First a congrats to Bill and his first flight! I hope I have a turn in the near future!! In spring, I tried to get some of the middle TN builders together for a burger and a chat. Just for acquaintance purposes as well as seeing what others are doing. Someone asked if I would try again and I thought about since we are close to Jabiru USA to see if we could get enough interest to A) just have the burger and a chat or B) see if we can add a visit to the Jabiru house and let them display their kits for the 601 and the 701 or any other products they wish to show case. Agian, this can be for central Tn area and/or for the 601 and 701 builders close enough to drive. If interested, respond and let me know. I will then have a number to tell Jabiru USA on visitors. I know they did it for EAA once! Rich Do not archive -- Thanks, Rich Simmons ________________________________ Message 24 ____________________________________ Time: 07:22:23 PM PST US Subject: Zenith-List: Re: Cooling the cockpit From: "GLJSOJ1" SOMETHING THAT I AM TRYING IS PUTTING A HEAT/COOL AIR VENT IN WITH THE HEATER, WHICH IS LOCATED NEAR THE FLOOR OF THE CABIN THIS WAY I CAN HAVE HEAT IN WINTER AND SWITCH IT TO COOL AIR WHEN HOT GLENN Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131281#131281 ________________________________ Message 25 ____________________________________ Time: 07:34:14 PM PST US Subject: Zenith-List: Re: N601BZ Fly's! From: "rgeese" Congratulations, Bill! I, like others, am very grateful to you for your website. I always seem to go to it when I have a problem, and usually find a solution there. Thanks for all your hard work in keeping it updated. It is appreciated. Our building speeds are about the same, so I could always depend on you for help. I had the same experience of "unintended flight" several years ago while high-speed taxi testing my Dragonfly MKI. All of a sudden everything got really quiet, and upon looking out at the end of the canard, found that my wheels were a couple of feet in the air. I firewalled the throttle and away I went for a 45 minute first flight. The thrill was indescribable. Again, congratulations, and please be safe!! Someday I hope to meet you in person-maybe on one of my business trips to VA. Do not archive. Ron Geese Columbus, Ohio Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131282#131282 ________________________________ Message 26 ____________________________________ Time: 07:42:15 PM PST US Subject: Zenith-List: Re: chat From: "Falcon" Dang, I missed another one. In my defense, wife and I were helping a friend assemble a Taylorcraft L-2, and having way too much fun watching this tube and fabric plane return to life. We'll be certain to catch you all next week. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131283#131283 ________________________________ Message 27 ____________________________________ Time: 10:04:50 PM PST US Subject: Zenith-List: Re: N601BZ Fly's! From: "PatrickW" Congrats! You inspire the rest of us. - Pat XL/Corvair Read this topic online here: http://forums.matronics.com/viewtopic.php?p=131295#131295 ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message zenith-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Zenith-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/zenith-list Browse Digests http://www.matronics.com/digest/zenith-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.