Pietenpol-List: Turnbuckles and hardwire

[matronics]

Original Posted By: "Larry V"
Group,I will deal with the tank question first, and then provide a "heads up" with an account of my experience with ethanol in auto fuel.My Pietenpol has a 12.5 Imp. gal. ( 15 US gal.) fuselage tank located in the nose. It is an expanded cross section of a Piper J3 tank, forming an ellipse which holds 3 US gallons more than the J3's 12 US gal. This tank provides ample clearance for the feet of the person in the front pit because it is mounted as high as the cowl behind the firewall will allow.Initially I used a Continental A-65, but substituted a C-85 early on and, although I was apprehensive about the C-85's increased fuel flow requirement, there has never been a fuel feed problem in over 700 hours with the C-85.However, totally unrelated to the fuel tank location, I did have a fuel flow problem caused by ethanol (5 to 6%) in the auto fuel I was using in my Pietenpol. For years, since 80/87 aviation fuel disappeared, I have used regular auto fuel without problems until this summer. I had long ago substituted steel float needles, in my Stromberg NAS3 carburetors, for the neoprene-tipped ones but, for some reason as yet undetermined, didn't realise the carburetor in my Piet still had the neoprene-tipped one until I had disassembled the unit. I installed a spare carburetor that I KNEW had the steel needle and, of course, it is unaffected by the ethanol in the fuel and works fine.Since then I measured and recorded dry dimensions of a new (old stock) neoprene-tipped needle and then placed it in a glass jar containing fresh-from-the-pump auto fuel. After about 5 hours I re-measured this needle and found it had "grown" appreciably. This would lower the fuel level in the float chamber causing a lean mixture which, at full throttle, could (and did) result in engine stoppage. I strongly recommend that anyone using auto fuel make certain that a steel float needle is installed in the NAS3 series carburetor, if they have one on their engine. The Delrin needle is an alternative to the neoprene type, but I don't know whether it is affected by ethanol, or not. Someone out there will know.I had flown for about 30 minutes with no problems, landed, and then attempted to take off again. It was a short flight. Luckily there was lots of runway ahead since I barely got airborne when things abruptly became quiet. The first thing I checked was the fuel flow to the carburetor and it was ample. The problem had to be in the carburetor...and it was. Why this didn't occur at the first takeoff perhaps could be explained by these factors:1. The oil was then cool and the engine didn't turn up to the critical rpm during the initial takeoff.2. I had recently installed a finer-pitched propeller, allowing the engine to rev up higher than it did with the other propeller.The engine must have been running "borderline lean" since the introduction of ethanol in auto fuel and these factors may have tipped the balance in favor of engine stoppage.My experience reminded me that the three most useless things in aviation are:1. The runway behind you. (Luckily, I started the takeoff with all of the runway ahead of me.)2. The altitude above you.3. The fuel you didn't put in the tanks.In nearly 61 years of flying, this is the first time an engine has quit on me at takeoff, and I'm glad things worked out the way they did. Back in the 1920's, Hereward DeHavilland (Geoffrey's brother) said in essence:"In order to survive, the aviator must be continually apprehensive."He was so right!Automotive gasoline has contained ethyl alcohol (5 to 6%) for several months in Canada, and this probably applies to the USA as well. This summer I encountered a service station that sold fuel containing 10% ethanol! (It was consumed by my automobile, though.) The above experience has caused me to wonder how ethanol might affect the flexible fuel lines in aircraft and my chemist/aviator friend and I are currently conducting tests on samples of aviation fuel hose and automotive fuel hose by immersing same in fresh auto fuel. We will keep you posted.Cheers,Graham Hansen (Pietenpol CF-AUN)________________________________________________________________________________Subject: Pietenpol-List: Turnbuckles and hardwire

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Original Posted By: "Greg Cardinal"
HelloI am working on the wing of my pietenpol and was wondering if anyone could tellme where to find the cross reference for 325 sf turnbuckles. Also the planscall for hardwire. I cannot seem to find this,and was wondering what size cableto use.Thanks Larry VRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

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Original Posted By: "Larry V"
Use 1/8" cable and AN155-32 turnbuckles. Attached is a pdf of a common cable assembly.Greg CardinalMinneapolis----- Original Message -----

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Original Posted By: "Barnwell Regional Airport"
Greg Thanks for the informationLarry VRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

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Original Posted By: "kevinpurtee"
Fellow Piet builders and flyers, Several weeks back, I posted a notice here about having a "regional" Piet fly in along with Corvair College #21 that will be held on November 11, 12 & 13 at Barnwell airport [ KBNL ] So far, no flying Piets have indicated they would attend. Some who normally would come have scheduling conflicts. There are about 8-10 builders to date who have indicated they will be here and want information on how to build their Piets.We will have my flying Piet, a static display of Don Harpers Piet on the gear with corvair engine, maybe a second static Piet fuselage with tail feathers, and we will hold a Brodhead forum type question/answer session in my hangar to discuss building tips, do's and don'ts. I'll have a rib jig and materials avaliable for those who want to learn how to build a rib.any questions/comments, let me knowP. F. Beck________________________________________________________________________________Subject: Pietenpol-List: Re: wings about to take shape

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Original Posted By: "BYD"
I made my tank from aluminum. It fits between the spars and the ribs. It holds16 gallons. A cross section of it is the same as the ribs. The top extends pastthe tank to mount it to some strips I put on top of the spars. It will justride on the ribs with rubber between. I am not real happy with the tank becauseit warped up from welding pretty bad. I am going to try to fix it but may buildanother one.--------Jerry Dotson59 Daniel Johnson RdBaker, FL 32531Started building NX510JD July, 2009now covering21" wheelsLycoming O-235 C 2CJay Anderson CloudCars prop 76 X 44Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Turnbuckles and hardwire

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Original Posted By: "Bill Church"
I think you'll find that all the cable in the Air Camper is 3/32 except for thecontrol stick to bell-crank (which is 1/8) and possibly the straight-axle landinggear support cables. This assumes you substitute the 14-gage hardwire with3/32 cable on the tail.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: Fuselage tank and the C-85 engine...and beware ethanolin au