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2" between a cruise and climb prop is quite small. I suppose it might vary with the difference in speed between cruise and climb too.

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12 hours ago, Kent Ashton said:

I have kept track of prop sizes as people discuss them and you won't find very many specified at 81.7" pitch.

Ha!  Thanks for the interesting read.  If I ever get brave enough to build a prop I will definitely be referring to your work.

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A newbie friend of mine was surprised to learn you could use auto plugs in an airplane!  And with magnetos!  (He is paying 32 Euros per plug).  I gave up magnetos a long time ago but G3i sells the instructions for how to modify the mag caps for 8.5mm auto wires.  http://www.g3ignition.com/magmod.html

Here is a Van's discussion with pictures of the process.   http://www.vansairforce.com/community/showthread.php?t=143892

I have used 18mm Autolite 386, Bosch M8ACO and a Champion version without inserts but mostly I used 14mm NGK BR9ES in 18mm inserts.  Frankly, I can't recall why I started with the NGKs+inserts; I probably read that Klaus uses them.  🙂  The 14mms and the 18mms seem to act the same in the engine.  I have never run a controlled test.  However, I was comparing the two plugs (pic- an old NGK and a new Autolite).  The 18mm Autolite seems to have a long electrode compared to the NGK.  Ordinarily a plug with a longer electrode is slower to conduct heat away and is a hotter plug due to the longer heat path--but both types seem to run at about the same electrode color.  

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Posted (edited)

Tricked again!  After a plug change I noticed that #1 was showing noticeable hotter CHTs than before--maybe 25-30 degrees hotter CHT and it was going over 425F in a climb which I don't like to see, although it WAS a pretty hot day.  So I  swapped in some new plugs, futzed around checking for an intake leak, test flew, pulled the EGT sensor out of the exhaust and had a look (normal) and finally borescoped the cylinder.    All looked normal.  Then I noticed that I had gotten sloppy and installed the upper cowl with the upper baffle folded inward so that plenum air was leaking around the baffle (pic 1).  I mounted the cowl correctly and voila (or "wall-ah" as some folks say), problem solved.

I used dams on the upper cowls.  It is just one way of doing it but the upper baffle must make a good seal against the plenum pressure below.  I have seen some new installations where the upper baffles flopped inboard--a guarantee of cooling problems with updraft cooling.  Pic 2 is how it normally looks.

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Edited by Kent Ashton
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The dams on the cowl appear to be an idea with good potential. Do you generally get good cooling without much trouble (when the baffles are resting correctly!)?

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The dams are per COZY MKIV plans.

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15 hours ago, Voidhawk9 said:

The dams on the cowl appear to be an idea with good potential. Do you generally get good cooling without much trouble (when the baffles are resting correctly!)?

The dams were not my idea but I do not recall upper cowl dams in the plans.   Regular floppy baffles will work there but they have to flop in the proper direction.  The main thing is to have no air leaks.  It's amazing all the little pockets  around a Lycoming cylinder and crankcase that will accommodate air leaks.  My CHTs at this time of year (summer here) average about 375-380.  On the EZ with downdraft, they were 25 deg. lower.  I built the cowls to Nat's plans but did not find the cooling all that even.   Below is what I have in the lower cowls to try to direct more air to the forward cylinders; those are about my 3rd iteration.    The CHTs move around a lot.  You can get them pretty even at one speed and then change speed and they are 15-20 degrees different.  Also, you can see in the pic above where I tried upper cowl louvers at one point and later removed them.   

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22 minutes ago, Kent Ashton said:

The CHTs move around a lot.  You can get them pretty even at one speed and then change speed and they are 15-20 degrees different.

With fuel injection and balanced EGT's, the CHT stay relatively even at a much wider range of power settings.

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6 hours ago, Marc Zeitlin said:

With fuel injection and balanced EGT's, the CHT stay relatively even at a much wider range of power settings.

Well sure, if you are some sort of rich inspector-of-canards charging innocents confiscatory amounts to bless their ill-informeed  purchases and can thereby finance  a mega-buck FI system.  I am using  a wick soaking in parrafin that only works after the wood fire is brought up to termperature.

 

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Posted (edited)

A couple last lessons from my hot-cylinder story:  It seemed like my torque wrench was applying way too much torque on the plugs.  A while back I welded two old sockets together so I could compare my clicker wrench against a beam wrench.  Holy cow, the clicker was at least 10 lb/ft off!  There are some decent tutorials on how to recalibrate the clicker wrenches.  Below is one.  Good to know because just taking one apart is not intuitively obvious although they are fairly simple.  This time I scribed the position of the calibration-adjuster nut for a quick check for future use.  I had screwed it way off.  Frankly, I didn't understand how the clicker's worked until now.  Bet I'm not the only one, though.     https://www.youtube.com/watch?v=FEZ-ajSksHs

I bought one of those Vivdia Ablescopes to have a look at the exhaust valves.  https://www.amazon.com/Vividia-Ablescope-VA-400-Borescope-Articulating/dp/B00GY7C9ZW/ref=sr_1_2/136-3577512-8573310?ie=UTF8&qid=1535143738&sr=8-2&keywords=vividia+ablescope   My exhaust valves looked quite good (pic)  700 hours on this engine.  I see a little oil collecting in the bottom of #4 that I must keep an eye on.  The oil-burning problems I have had all occurred on the professionally-overhauled cylinders.  The cylinders I honed at home seem to be good.  http://forum.canardaviation.com/showpost.php?p=69232&postcount=41

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Edited by Kent Ashton
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Kent, is it possible you are having too much fun?

 

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10 hours ago, mquinn6 said:

Kent, is it possible you are having too much fun?

And soon you'll be joining me, Mike.   : - )  

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On 8/23/2018 at 5:11 PM, Kent Ashton said:

Well sure, if you are some sort of rich inspector-of-canards charging innocents confiscatory amounts to bless their ill-informeed  purchases and can thereby finance  a mega-buck FI system.  I am using  a wick soaking in parrafin that only works after the wood fire is brought up to termperature.

 

I'm sorry - what? I missed that - too busy here eating caviar and grapes that the servants have peeled for me. We roast the servants after they've outlived their usefulness using benjamins as the fuel for the BBQ fire. The riches I've obtained from this business fund all the Boeing Business Jets that Burnside Aerospace leases.

Back to playing in my pile of jewels...

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I want to join Marc instead Kent!  He seems to know something that we do not, apparently...

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On 8/25/2018 at 6:17 PM, Marc Zeitlin said:

The riches I've obtained from this business fund all the Boeing Business Jets that Burnside Aerospace leases.

Apparently I am one of those "ill-informed innocents" as I arranged for Marc to do a post-buy inspection on the Quickie Tri-Q200 I purchased.  Marc went through the entire aircraft with me, found a few notable items that I would have not, and left me in a position with more knowledge and direction than I had before I started.

He was thorough and professional, and just as we were starting to have some fun Marc's staff rolled up his red carpet and he was off.  😉 

Seriously, that all happened (without the red carpet part).  I wasn't exploited in any way and was happy to pay for Marc's services.  We are all members of the same family, so let's keep this cordial. 

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Posted (edited)

Jon, it was intended as a joke.  Marc know hows much I respect his work and opinions

Edited by Kent Ashton
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8 hours ago, Kent Ashton said:

Jon, it was intended as a joke.  Marc know hows much I respect his work and opinions

And I clearly understood it as such :-). While I'm happy to get a "happy customer report", it wasn't necessary to defend me. I particularly liked the paraffin soaked wick - reminded me of the old Lucas electrical system in English sports cars - an elaborate system of tallow candles, was how they were described.

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Great then!  I was concerned that two of my canard-building/flying idols were not on good terms.  :grouphug:

I'll have to look up those paraffin and Lucas references...

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Here is a DXF file of the winglet alignment jig I mentioned earlier in this thread.  IMO, it's a much more reliable way to align a winglet although the wing must be mounted on the aircraft to compare the winglet chord to A/C centerline.  The plans do not say so directly, but doing the trig shows that the winglet chord is intended to align with the A/C centerline.  It is worth moving an airplane outdoors to mount the wings, determine the A/C centerline and get this right!

WingletAlignJig.dxf

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A buddy of mine is rebuilding a Cozy and came up with a good idea for mounting avionics trays using sheets of BID.  I think I would rather use thin BID-foam-BID sandwiches versus the single layers but I like the idea.  It's quick to make and install.  If you ever want to change avionics, they'd be quick to cut away and build new supports.  I have generally used aluminum angles to make tray supports but it's fiddly.

Yes, we have discussed the PVC wiring.

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Nice idea, easy and light, too.

Maybe with a coremat core it would be stiffer, that might be easier and lighter than a sheet of foam (once you take into account the slurry in the surface and so on), depending on the details. And more accepting of being screwed through without crushing perhaps.

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I'm using a little for some small parts, 2mm I think is the thickness I have. Makes for a nice stiff part, where just glass isn't quite enough without a bunch of plies, which would be heavier.

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22 hours ago, Kent Ashton said:

A buddy of mine is rebuilding a Cozy and came up with a good idea for mounting avionics trays using sheets of BID.  I think I would rather use thin BID-foam-BID sandwiches versus the single layers but I like the idea.  It's quick to make and install.  If you ever want to change avionics, they'd be quick to cut away and build new supports.  I have generally used aluminum angles to make tray supports but it's fiddly.

That's great -- I think I will copy that design!  Coremat as a core material reminded me of the Mini-IMP and Molt Taylor's TPG (Taylor Paper-glass) which follows the same principle.  This is basically creating box structures; something we do all the time with foam, but in just a smaller scale here.  You could even use balsa wood for this application.

I missed the memo on "PVC wiring".  What exactly is it and what's wrong with it?

 

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1 hour ago, Jon Matcho said:

I missed the memo on "PVC wiring".  What exactly is it and what's wrong with it?

Bob Nuckolls (Aeroelectric.com) says PVC is not particularly unsafe-- lot of airplanes have used PVC--but Tefzel (Teflon) and/or PTFE is better.  The latter uses tinned strands, the cover has a higher melting point, is thinner and more resistant to cuts and tie-wrap pinching, and can be had in a lot of color combinations.  

Do you have his book?  A must-have for builders.   http://www.aeroelectric.com/Catalog/pub/pub.html

See also: https://www.canardzone.com/forums/topic/18661-kents-long-ez-project/?do=findComment&comment=61303

 

 

Edited by Kent Ashton
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