Brodhead Pietenpol Association

Original Posted By: Gerry Holland
Guys,There is a group of engineers at The Univ. of Houston (my part of TX), that isin the process of establishing pure ethanol as the fuel for GA piston aircraft.According to the guy I know, they have already filled out paperwork to have thefuel approved by the FAA for C-150's, 152's, and a host of other aircraft upto 200 Hp. In order to certify, they had to change out all rubber components in the fuel systemto polyurethane, which is completely resistant to the swelling that occurswith rubber. Along with the polyurethane, they have worked thru many of theissues related to mixture, leaning, etc. Their intent is to certify GA pistona/c for use with both fuels, or heavy blends of Ethanol.Just my .02 for what it's worth...--------Tom KreinerRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Wed, 07 Jul 2010 17:59:38 +0100Subject: Pietenpol-List: Continental A75 Eyebrows

Original Posted By: H RULE

Original Posted By: Jim Ash

Original Posted By: Jeff Boatright

Original Posted By: Ryan Mueller
Subject: Re: Pietenpol-List: Continental A75 Eyebrows

Original Posted By: Gerry Holland
Subject: Re: Pietenpol-List: Continental A75 Eyebrows

Original Posted By: Jim Ash

Original Posted By: owner-pietenpol-list-server(at)matronics.com
As Harry Fenton (the Guru of small Continental engines) told me, anyairplane that doesn't have cooling shrouds or a pressure cowling willeventually have problems with the cylinders due to insufficient cooling. Ihad pointed out a Rose Parrakeet that had no shrouds at all. He just said"it's a matter of time". And I can tell you, any time you have cylinderproblems, those are EXPENSIVE problems.I just made a new set of shrouds for my Pietenpol after my initial setcracked for the third time (new set is thicker, stronger material). It onlytook a few hours' work to make a set, when you have the old set for apattern.Jack PhillipsNX899JPRaleigh, NC _____

Original Posted By: Jim Ash

Original Posted By: "Jack Phillips"
Jeff, Harvey, et al,As for fuel attacking the carburetor, and/or other components in the fuel system,what has been found so far is that most of the gaskets made from 30's vintagegasket paper (nearly everything in an aircraft carb), had not suffered anyeffects from fuels containing ethanol. The preliminary indications are that,with the simple change from neoprene hoses to polyurethane, along with a new,or modified (don't know which) mixture cable/control, a/c engines will run a widerange of mixtures of ethanol, up to, and including, pure ethanol. Obviously,there will be a learning curve as to how to prevent the accumulation of moisture,along with a host of other items.While I believe the group on the study has been involved with the teardown of carbs, I have not heard any specific information about their findings. One couldspeculate that an examination would be required in order to ensure internalcorrosion is not a factor. The next time I speak with my contact, I'll be sureto inquire about any other effects.As far as I currently know, however, the only required changes were in the rubbermaterials used in the hoses, etc. Viton O-Rings are completely imperviousto any concentration of alcohols, and one would assume that a Viton tipped floatneedle would also be impervious. That would have to be verified, however,and it's probably in the works. (If, in fact, a 1980's material such as Vitonhas actually been approved by the FAA...)When additional information becomes available, I'll add a post to mention it.--------Tom KreinerRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Original cracking was on the bracket that attached the left shroud to therocker box covers. The bracket was 2024-T3 aluminum, while the shrouds were.025" 3003 1/4 hard aluminum. First the left forward bracket broke, thenthe left rear, then the right forward, so I replaced all the brackets withsteel. Then on the way to Sun 'n' Fun this year the left shroud crackedstarting at the rivets that attached the left front bracket. I patched itat SNF and then when I got home I made all new shrouds and brackets, using.032" 5052 - H32 aluminum for the shrouds and .062" 4130 steel for thebrackets. So far so good.Jack PhillipsNX899JPRaleigh, NC-----Original Message-----

Original Posted By: Jim Ash
Transponders:I duno the way I read 91.215 is that I'm ok without a xponder, even with a generator,as long as I stay out of a 30 mile radius of airports that are in appendixD section 1. (I haven't read that, but I think it's class B, D, and uh some others.)And stay below 10,000 ft.Any thoughts on that one?HAHAHA 200 indicated hu? Maybe 200 ft. per hour.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Wed, 7 Jul 2010 18:50:32 -0400 (EDT)

Original Posted By: Oscar Zuniga
Jack wrote->Original cracking was on the bracket that attached>the left shroud to the rocker box covers. First the>left forward bracket broke, then the left rear, then>the right forwardMy exact experience with the A65, continuing now withthe A75. I get fatigue cracking in one per year, becauseit seems like that has been a squawk at every annual. Ihave one cracking right now.I'm going to try your combination of metal type andthickness this time, since I need to rework the eyebrowsanyway... it gets a little rough around the spark plugholes with dead-soft aluminum and clumsy wrenches andI may as well remake the eyebrows.PS, whoever mentioned that the eyebrows are mirror imagesforgot that the cylinder banks are staggered. See:http://www.flysquirrel.net/piets/repair ... 2.JPGOscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________

Original Posted By: Jim Ash

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Tried that. Apparently the eyebrows just take a heck of a beating from theslipstream (particularly the left one, since it always cracks first).Jack PhillipsNX899JPRaleigh, NC-----Original Message-----

Original Posted By: "Jack Phillips"
It's not evident from the camera angle, but if you want the leading edges of theeyebrows to be even with each other and equidistant from the rear of the prop,one eyebrow will be longer/deeper than the other.I hadn't thought of using doublers on the tabs. Others have mentioned making thetabs out of steel so that was what I was going to do instead of continuingto fuss with aluminum and fatigue cracks. However, I also found a crack in themetal "L"-piece that mounts to the top of the engine, that the aluminum eyebrowattaches to by the engine case parting line and that piece is light gaugesteel. Vibration and the pulsing beat of the propwash take their toll.Maybe I should ditch this shaky old antique 4-banger and go with a smooth 6-cylinderCorvair instead ;o)--------Oscar ZunigaSan Antonio, TXAir Camper NX41CCRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: owner-pietenpol-list-server(at)matronics.com
That brings up a good point, Oscar. The angle bracket that the shroudsattach to on top of the engine should be made of steel. It gets trappedunder the top cylinder base nuts and has to remain tightly torqued. If thatbracket is aluminum over time it will relax and reduce the torque on thosetop nuts, which are required to hold the cylinders on. My brackets are.050" thick 4130 steel, with nutplates to attach the shrouds and those arethe only parts on the whole shroud assembly that have given no trouble.Jack PhillipsNX899JPRaleigh, NC-----Original Message-----

Original Posted By: Dan Yocum
Mine is the dreaded GN-1 version but one thing that was very apparent when I hungit-bought this plane project with wings and center section and flop glued up.he made the flop the same width as the center section and once the wings werehung there is about 2" on each side gap since the space for connecting thewing root brackets has to be covered too so if you don't put the wings togetherwith the center section or measure and add you'll need to allow for that space.RaymondRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 08 Jul 2010 10:02:33 -0500

Original Posted By: Jim Ash

Original Posted By: Rick Holland
Subject: Re: Pietenpol-List: Re: Continental A75 Eyebrows

Original Posted By: "Chris"
Mine haven't started cracking at the tabs, but they're reinforced. I'm sure they're original - 420+ hours:http://5n429glenoak.homelinux.net/galle ... sIndex=1-- yocum(at)gmail.comOn Jul 10, 2010, at 5:44 PM, Rick Holland wrote:> Have aluminum eyebrows on my Corvair also that will probably start cracking after a few hundred hours too. The third law of thermodynamics - nature tends toward increased randomness, and a cracked eyebrow (or anything else) is more random than a perfect one.> > rick> > On Thu, Jul 8, 2010 at 7:24 AM, taildrags wrote:> > It's not evident from the camera angle, but if you want the leading edges of the eyebrows to be even with each other and equidistant from the rear of the prop, one eyebrow will be longer/deeper than the other.> > I hadn't thought of using doublers on the tabs. Others have mentioned making the tabs out of steel so that was what I was going to do instead of continuing to fuss with aluminum and fatigue cracks. However, I also found a crack in the metal "L"-piece that mounts to the top of the engine, that the aluminum eyebrow attaches to by the engine case parting line and that piece is light gauge steel. Vibration and the pulsing beat of the propwash take their toll.> > Maybe I should ditch this shaky old antique 4-banger and go with a smooth 6-cylinder Corvair instead ;o)> > --------> Oscar Zuniga> San Antonio, TX> Air Camper NX41CC> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 169#304169> > > > > > > > ==========> st" target="_blank">http://www.matronics.com/Navigator?Pietenpol-List> ==========> http://forums.matronics.com> ==========> le, List Admin.> ="_blank">http://www.matronics.com/contribution> ==========> > > > > > > -- > Rick Holland> Castle Rock, Colorado> > "Logic is a wreath of pretty flowers, that smell bad" > > ============================================================================================================================================> ________________________________________________________________________________

Original Posted By: Dan Yocum
Wow, Dan... that is quite a long engine mount onyour airplane. Reminds me of the mount on ErnieMoreno's airplane with the Franklin engine... quitean extended mount.I see what you mean about those reinforced tabs onyour eyebrow mounts. Maybe that's what I'll try,since yours seem to be very simple and obviouslyhave held up. Add some doublers to the eyebrowsand then just use straight tabs.Oscar ZunigaAir Camper NX41CCSan Antonio, TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net ________________________________________________________________________________Date: Sun, 11 Jul 2010 13:42:45 -0500