Turbo

I reckon a pair of extras wouldn't hurt!  I'll send you a check.    Think I still have your addy.

I'll text you mine.

Appreciate the offer, Vance.  Maybe there is a screw-top NGK plug  BPR8E (or something) that would work with those caps.  Have you ordered the new plugs yet?  I went to a shop that sells chainsaws and offroad vehicles and bought their last 2 BPR8ES solid-top plugs.  Paid too much, but had a hard time finding them in the auto parts stores.  I'm about 4 gallons of premix away from putting on your OI pump!  Again thanks for that!

Thanks, Vance!  I was trying to validate this.  Measured old BR8ES at 4.7kOhm.  Both say they have copper core.  Both have "R" on one side of the insulator.  

The NGK BR8ES plugs are listed as having 5kOhm resistence.  The BPR8ES  plugs show up as copper core.  Should I expect a hit on radio communications?

Dude, I did my own pre-purchase inspection.  You can too.  These birds are simple but elegant in their design, and stout.  My advice, FWIW, is to read up and learn as much as you can on this site and others.  Take stock of your own competencies: engine mechanical stuff, electrical, welding, fabric work, etc., then look out for problems on the bird that align with your weaknesses.  On Avids, the flaperon hangars are a weak point, as they are essentially hi-grade plywood painted over with dope.  But there are 5 per side (fewer on the speedwing versions).  If one or more is broken or weak, some complex wood-and fabric work would be in your future.  All the engine stuff is pricey, so pay good attention to that being correct.  If possible take a look into the exhaust ports for scuffing on the cylinder walls, piston carbon or lead fowling, etc.  On this site the guys are awesome and knowledgeable, and will welcome and advise you along the way!  And what a journey it is!  Good luck, and welcome!

Just a question:  Do you carry extra plugs just so you can easily swap in clean ones?  These one-piece items don't wear out (well, they do but only very slowly), but they do crud up if engine conditions aren't right.  One could just as well carry the wherewithall to clean & maybe gap them.

Thanks, guys!  True, I don't fly often enough!  Last time up it felt chilly!  Does NGK  make a BR8ES-P plug?   I'm so glad there's a simple answer out there!  I will definitely pursue this.  Thanks, Fred, for going the extra  mile  (or couple of km).

So here's another con.  Of course it's way more convenient when stopping for gas on a cross-country, as you don't have to guess how much petrol you're going to buy, then add the appropriate amount of oil to the gas tank before filling the tanks, but here's another reason: If you do any cruising at high altitude, such as if you're going over high or difficult terrain, you will likely want a leaning system as well, so your engine is not running overly rich on fuel, reducing your range.  However, running leaned out at altitude, and likely at higher RPM, with premix, less gas means less lubrication, whereas with the oil injection you get the same oil flow, even though you're burning less fuel.  The OI system only responds to two things: engine speed (RPMs) and throttle position.  My bird was set up for premix, and I am going back to the OI system, principally for these two reasons.  Reason 3: every time I go to fly, I have to pull a couple of plugs, and shake & wipe them clear of oil so my engine will start.  With the OI system putting proportionally less oil in at idle, maybe this inconvenience will be mitigated.

The only correct way to revert to premix is to disable the oil injection pump.  Some people completely remove it and fabricate a plate to cover the opening, but most simply remove the plastic gear that drives the pump, then put the pump back on.  The pump itself mounts below and between the two carburetors (above if we're talking Kitfox, with the upright engine).  Here's a pic of the (disabled) pump from below, on my Avid with the inverted (plugs-down) engine.  That squarish metal thing on the upper left is the bottom view of the aft carburetor's float bowl.  The white plastic gear on the oil injection pump shaft won't fit thru the hole where the pump mounts, but the housings are layered, and removing the next layer allows access.  All this engine stuff is pricey, so hopefully the seller has the pump and that white plastic gear, as well as the Bowden cable to tie in to throttle position!  The pump has two "banjo" (shaped) fittings which connect via small plastic line to the injection ports.  Maybe the banjo fittings are more visible on the second pic.  With typical strong pressure pulsations of 70-100 cycles per second at cruise there's no need to actually spray the oil at high pressure.  I think it just dribbles in, but gets essentially atomized by the pulsations.  Visible on the upper right is the oil inlet connector tube, blocked off here with some red plastic.

Hi Y'all,

Every time I go to fly my Avid I have to pull a couple of plugs, then shake and wipe away excess oil, then reinstall, otherwise I can't easily get the engine to start.  I have a grey head 582, and am still burning down my premix before reinstalling the OI system.  Do we all share this misery?  Will the lower oil flow when idling with the OI system mitigate this problem?  I have the pull starter, so really feel it when the engine won't start.  BTW, I shut down by turning the fuel valve to off, then waiting the couple of minutes for the engine to shudder to a stop.

Brilliant work on the wings!  On the cowl bulge, I was contemplating making one, but find myself pulling a spark plug  or two to clear off oil almost every time I fly, as otherwise I have a hard time hand-starting the engine.  In my view this is the chief disadvantage of the inverted engine, at least burning premix.  I now am just going to leave that hole in my cowl to allow front-cylinder spark plug access without cowl removal.   I agree that the gap between flaperon leading edge and wing trailing edge is not optimal aerodynamically, but may be necessary for folding.  

One benefit of the bellyrad is the aerodynamic shielding of those draggy round landing gear legs just behind, and tucked up against the belly.  I think that shielding helps reduce the penalty for just sticking that rad out in the stream, uncowled.  Of course, nothing says that cowling the rad will automatically reduce drag - that would require flight test data and careful aero design based on same, with some design iteration.

Another thought for improving cooling would be some kind of extended gill flap to help suck air thru the radiator.   That option, however, is inconsistent with the current bellyrad, as the rad will kill the momentum in that near-wall flow, so deflecting it away to create suction over the current in-cowl radiator's air exit would likely be futile.  Here is a great opportunity for a variable cowl flap, which could be closed down in  cold cruise conditions to reduce drag!

It's more fun just putting around the sky anyways, unless you're actually trying to get somewhere.  You Alaska flyers amaze me.  I must still be a little shy of trusting the 582 like you guys do.  Hey, I'm still trying to nail down my landings.

BTW, it's easy to go fast when you're descending.  

Based on the sandbag test in the Avid literature, the maneuvering speed Va should be 104 mph.  Why they list something lower as never-exceed speed I don't understand.  That Va I quoted is equivalent airspeed, or EAS.  Errors in the static pressure measurement could easily cause your ASI to read high or low, though.  Change AOA, open or close your vents?  All act to bugger the cabin pressure, which is used as the static pressure.  I'm tempted to build a static cone or other device to try to get a decent static pressure measurement then calibrate the ASI.  The total, or ram pressure is relatively easy to measure accurately.  The static is difficult to get right.

Now that's a real tanker, not like those micky mouse 135s!  Just keep your tailfeathers clear of #2's exhaust!

Nice work, Chop!  Wonder how many mph those fairings will yield..

Fred,  I did not notice that "strip".  Sounds like a lower-altitude pass is in order. Orientation to wind looks correct.  However, when I blew up the pic on my tablet, it did not look like an airstip.  The aeronautical chart shows no airstrip there.

Great Idea,Vance!  Do I hear the rumblings of a NW fly-in?  Wouldn't it be great to put faces to the names, and get to know the many Avid fliers in our area!  Not to mention getting in-flight pix of our birds!   I see, flying with THE MACHINIST you got some great pix of your beautiful bird!

Hi Guys.  Just thought i'd post a few pix from my home stomping grounds - the Columbia River Gorge.  My Avid C, N23PB, is in good health, and although she's a little on the plain side, she's got the magic.  Got in about 1.2 hrs today 9/18/2018.  Overflying a friend's house I thought I'd call him on the cell.  Took off the headphones and YOW, it's way too noisy!  Oh well.  I'm getting about 80 mph indicated at 4500 rpm, low altitude.  Not bad!  - Turbo

Very cool, Vance!  Your bird looks so nice!  It's hard to just practice landings when there's so much sky beckoning!

Fight on, Ed!  We need your wit, wisdom, and adventurous spirit.

Ignore what they say.  Watch what they do.  Go Trump!  Massive climate change from 15k to 12k years ago helped shape the Columbia gorge.  Climate stasis is the myth!  Totally with you, brah!

Your wire wrap looks great, but may be twice as long as needed.  Note that this type of bungee cord can stretch fully 100% of its original length.  Slippage of the shock cord inside the wire wrap will occur if the cord is not stretched sufficiently when wrapped, since the long end will shrink in diameter when stretched.  If stretched beyond the condition at which it was wrapped, it will slip, shrinking the eye.   

Fred double-wraps his ends; I think this is a good idea.  I built a wooden gantry with 6:1 purchase using pullies, which allowed me to re-rig the bungees without help.  I shied away from heat-shrink, and just used electrical tape.

Checking my flaps, I got a similar result.  Made me wonder how to even get more than 15 degs flap deflection.  Hey, congrats on getting your issues ironed out!  Great pix, too!  BTW, I am very close to putting the OI system in play. Gotta burn off 10+gallons of premix first!  Again, thanks!

As Nlappos indicated, these Bing carburetors are not ideal for airplane use.  I agree.  My approach has been to rig an altitude compensation setup like the one Cowlove came up with, using reduced float-bowl pressure for leaning, then jet the carbs as if I were flying out of someplace near sea level.  Well, actually I am, since the Columbia basin bottoms out just a little above S.L.. Having it set up as if you're flying out of an airport at sea level is important if you ever go into a field lower in density altitude than your home field, as you won't be running too lean on T/O and climbout.   Cowlove's solution used a small, 12V diaphragm suction pump, hooked up to a 100 ohm, (5 watt) rheostat, sucking on all the float-bowl ports, and working opposite a drilled-hole "calibrated orifice", since, even at the roughly1/2 atmosphere vacuum that the pump can generate, it's way too much (like leaning for 18000 ft!).  I'll see if I can find his explanation & pics.  It's freakin' elegant!  The suction pumps are apparently used for certain medical devices and are super cheap.  Mine came from China and cost under $2.00!  I have not flown my plane at altitude using the system yet, but Cowlove shows a panel pic of his Catalina at 13999 ft, indicating 60 mph, and 6000 rpm!  If I lean too much at idle I can easily kill the engine, so I think I'm in the ballpark.

The nice thing about leaning with float-bowl pressure is that it affects all 3 of the carb's circuits.  The Arctic Sparrow leaning system, if I understand it correctly, would leave the Idle and main jets unaffected (and too rich) at altitude.  Even with our planes' awesome T/O and climb performance, having the ability to lean for high density altitude takeoffs (and cruise) makes sense.  Still - too lean means high EGT.

Found Cowlove's post!  It's under "Rotax and other engines"/"Leaning the carbs for altitude - on the cheap" .  FWIW.

Sorry if all this seems tangential.  It's just that this business of setting up for one field elevation seems to me to be too limiting.