Good old number 29

Contributing Member
 View profile  See their activity

  • Content count

    125

  • Joined

  • Last visited


Community Reputation

170 Excellent

About Good old number 29

  • Rank
    Advanced Member

Recent Profile Visitors


2,143 profile views

Good old number 29's Activity



  1. Good old number 29 added a post in a topic CONTRIBUTIONS TO KEEP SITE GOING   

    Thanks again, Leonard, for keeping the site going. It’s a great thing. 
     
    For those of you who use Venmo, rather than Paypal, you can contribute to Leonard Perry, the mastermind behind this site, @alaskaflyer2000
    To anyone who has found this site valuable, you can help support it by making a contribution. If you like reading through the posts, without being interrupted by ads popping up, please recognize and support it continuing this way. 
     
    Thank you, also, to the many who have also contributed knowledge and information to this site. Your posts and insights have enrichened us all.  
     
    Let’s work to keep this resource open and available. 
    • 2


  2. Good old number 29 added a post in a topic Kitfox 4 build # 2   

    How is this one coming along? I like what you did with the hub adapters. I’ve really been happy with the 1/14” gear on mine, but sometimes wish I could use the 8” wheels and lighter tires. 
    • 0


  3. Good old number 29 added a topic in Avid fox flyers pics and vids   

    Quick trip to the glacier strip
    Here are some pics of a recent short flight across the bay. I hope you’re all enjoying your planes as much as I do. 





    • 1 reply
    • 253 views


  4. Good old number 29 added a post in a topic I can’t believe it’s not winter   



  5. Good old number 29 added a topic in Avid fox flyers pics and vids   

    I can’t believe it’s not winter
    I’ve been enjoying the last bit of winter, here in my neck of the woods. The snow will be too far gone, on my home strip, for skis, after this week. 

    I did find the limits of my Federal 1500 skis, a few days ago. Eighteen inches of rotten snow, loose, wet, granulated ice, under four or five inches of crust. Sorry, no pictures of that adventure. Yes, I did fly out of it, after getting unstuck for the sixth time. 
     
    Two lessons from that. One, hard crust in the morning can be a very soft mess in the afternoon. Two, skin those skis with plastic to widen them. I’ve thought about it since I got them, but never had a problem until now. It’s a good thing I didn’t find those limitations on a glacier, or in the mountains. 
     
    Misadventures aside, I’m enjoying the nice warm weather, and being careful where and when I land. 
     
     





    • 2 replies
    • 1,436 views


  6. Good old number 29 added a post in a topic Running lean   

    After pulling apart the top end and taking some careful measurements, it appears that the bore is well within spec, but the pistons are worn past maximum spec for piston to bore clearance. 
    The original pistons are stamped 71.92 mm (not the 7.93/7.94 red dot/green dot spec), but measured at 71.755mm. The bore measured at 71.99 mm, still slightly under the original 72 mm spec. That put the piston to bore clearance at .235 mm, which is more than the maximum allowable clearance of .2 mm, and well beyond the .07-.09 mm build spec.
    Ring end gap was at .65 mm, still less than the 1 mm max, which seems huge. The rings were a bit eaten up, with surface pitting particularly noticeable on the top rings of each piston. The exhaust ball joint had also broken apart, ending up in the muffler. Remember where it says to lube that with high-temp antiseize? Another good thing to remember. That allowed a minor exhaust leak at the y-pipe, which is likely to have contributed to burning out the rings.
    There is minor scoring in the cylinders, only below the exhaust ports, just enough to catch a fingernail. 
    I believe that the loosened tolerances of the well-worn engine helped to prevent a seizure during the high temp takeoff. Prior to my ownership, it had once been hot-seized on takeoff, caused by an improperly installed fan. The owner made the impossible turn back to landing. 
    All things considered, not bad for an engine that’s going on 39 years since manufacture, and 500 hours. 
    I’m tempted to hone the cylinders and just replace the pistons and rings, but that leaves me questioning the center crank bearings and big end rod bearings, which are still original. Even more to think about, since it is an early Provision 4 motor, with single ignition. 
    It sure has been a good engine. I have to say that the simple, lightweight engines, like this 503, have really been underrated. People laugh when they hear it has 50 horsepower, but lots of planes were built to fly with that much power, and lots of them are still around. There might be something to it. 
    • 4


  7. Good old number 29 added a post in a topic Tail ski   

    Good turning radius, especially in soft snow. I could turn sharper, but wouldn’t want to twist an axle. The lighter tail makes it easier to lift with the elevator, and swing around. Tracks straight with the tail down, with proper surfaces. 
    • 1


  8. Good old number 29 added a post in a topic Tail ski   

    That looks good. I was originally thinking of doing a penetration ski, but decided that it made more sense for me to use a straight tail ski, since I have straight skis in the front. I’m planning to make a set of penetration skis to go all the way around, in the long term. This tail ski was a kind of pilot project to test the structure and see how it worked. 
    After I decided on a straight ski, I was considering how to mount it, possibly using a Matco or Maule tailwheel assembly. I had some concerns about the pivot unlocking. Maybe unfounded, because a lot of guys run these, but imagine what would happen if it spun around. You’d want to be careful that there was enough ski in the back, behind the pivot point, that it could straighten itself out, and not just run backwards, and also that it wouldn’t dig in if it spun around. 
    So, I settled on using a fixed ski, bolted directly to the tail spring. I set it in glass, so the mount is formed to the spring, holding the ski perfectly straight. And, it works. It actually turns much tighter than it did with the wheel in back. The tail lifts easier, being over five pounds lighter, and it has a higher angle of attack, in a three point stance, since the ski is several inches shorter than the wheel. No cables or rigging, just one nut on the bolt that’s glassed into the ski, and off you go. 
    As an added bonus, I also found that the tailwheel springs had nearly worn through the holes on the rudder horn, as Alaskaflyer also recently saw on his Avid, so I get to fix that without the pain of finding it the hard way. 
    • 1


  9. Good old number 29 added a post in a topic Tail ski   



  10. Good old number 29 added a topic in Technical tasks   

    Tail ski
    Just tried out my prototype tail ski. I’m happy with it. After fifteen minutes of typing a detailed description on Facebook, the page reloaded and deleted everything. Here are some pics. I’ve identified improvements, but am only happy with the results. 2.25 pounds without paint, fiberglass over foam. Turns sharper than with the steerable tailwheel, but lighter rudder feel, and no loss of steerability or rudder authority. Solid success. 
    • 4 replies
    • 742 views


  11. Good old number 29 added a topic in Technical tasks   

    Tail ski
    Just tried out my prototype tail ski. I’m happy with it. After fifteen minutes of typing a detailed description on Facebook, the page reloaded and deleted everything. Here are some pics. I’ve identified improvements, but am only happy with the results. 2.25 pounds without paint, fiberglass over foam. Turns sharper than with the steerable tailwheel, but lighter rudder feel, and no loss of steerability or rudder authority. Solid success. 





    • 0 replies
    • 379 views


  12. Good old number 29 added a post in a topic Running lean   

    It’s about 450 lb. Those would be great options. I kind of like the idea of going to a four stroke. 
    • 0


  13. Good old number 29 added a topic in Rotax and other engines   

    Running lean
    It’s getting to be time to rebuild or replace the tired, old, original 503 in my Kitfox 1. I freshened it up with new crank end bearings, when I bought it, at 196 hours. As of today, it’s at 480 hours, so it’s really close to the recommended 300 hours for a complete crankshaft overhaul. We didn’t separate the crank and replace the center bearings or big end rod bearings, when we did the outers, so it definitely needs to have the whole thing done. 
    Aside from that, it has lost compression, due to a lean running event, this fall. I took a long cross-country trip to interior Alaska. I had the prop pitched for cruise, and jetted accordingly, but after an overnight in Talkeetna, I took off at -10°, saw over 1,200 on the EGT gauges, easing off the throttle to get cooler temps, but the damage was done. Since the EGT probes are calibrated at 70°F (a fact I had forgotten), that adds another 80° (the difference between 70° and -10°), meaning the temps were actually in excess of 1,300. Yikes! 
    Anyway, it was a great trip and I made it home safely, but the loss of compression is fairly obvious. The prop keeps turning the engine over for a couple revolutions when I shut it off. I had to pitch the prop down to get enough RPMs for takeoff, but the takeoff run increased from 250 feet to 500, due to the lack of power. A compression gauge has both cylinders around 91 psi, which I’d consider to be low for this engine, but I don’t know what it was, before. 
    After that incident, I pulled apart the top end and de-carboned the cylinders. No cylinder scuffing or melted pistons, so I put it back together. I might have honed the cylinders and replaced the rings, and possibly the pistons, but I know it’s time to do the crank, so I didn’t want to do the top end without taking care of the rest. 
    While I had the engine off the plane, I also checked the points and changed the gear oil in the B box. Timing was in the middle of spec, but .005” different between cylinders, so I opened the points back up to max advance, the same on both cylinders. The oil in the gear box did not have any metal in it, but was dark, which it had not been at any other time. Having considered this awhile, I concluded that it was most likely caused by blow-by past the pistons, pressurizing the crankcase and pushing carbon past the crank seal, into the gearbox. 
    So, like it or not, it looks like time to take care of the old girl. It is the original engine, ordered with the plane in late 1984. I do want to take care of it and keep it all together, but it is underpowered and a single ignition, so I’m considering an upgrade. Unfortunately, my pocketbook is also running lean, so options are very limited.
    My first choice might be an MZ202, with less weight and more power, but a new one, at ten grand, is out of the question. New 582 engines are apparently still available, but similarly expensive. I like the Yamaha Phazer conversion, which would require more work on my part, but could be done for less than a new 582, if I was good about it. I’m wary about purchasing a used engine from someone I don’t know, but a provision 8, dual ignition 503 or 582 would be an improvement, with the bigger crank bearing and dual ignition. Or a 670, for that matter. 
    For the cost, I might just rebuild the original motor and  run it, but it seems like a good time to upgrade. If anyone here has something available, that would be suitable, let me know. 
    And, as always, be careful about running too lean.

    • 5 replies
    • 924 views


  14. Good old number 29 added a topic in Avidfoxflyers General Hangar   

    Scrappy specs
    I loosely followed Mike Patey’s “Scrappy” build. He had some great concepts. Has anyone seen performance specs on it? I saw that it weighs a ton, 2,500 pounds, or so, and that it had 600 horsepower before he adds twin turbos, but does anyone have details on the real world performance, like takeoff and landing distance, or VS0 or VNO?
    I’d love to take it for a spin. It is rated for spins, right? Jokes aside, I’d be really interested to see and feel how it actually handles on the ground and in the air. I wonder if he saves any of his good ideas for another plane, or just crams them all into the one he’s working on at the time. Might as well try it all, then sort out which ideas work best in another application, later on. 
    I’d like to see some of those features, like the leading edge slats and suspension, incorporated into a lighter, simpler design. I’d guess we’ll see some of that in his new Draco project. 
    It has a heavier empty weight than a Helio Courier, and I’d assume the gross weight is higher, too. More horsepower. I wonder how Scrappy compares to other planes of similar weight or horsepower or dimensions. It’s kind of in a category of its own. Any word on performance specs?
    • 1 reply
    • 1,273 views


  15. Good old number 29 added a post in a topic Added 1 degree pitch to my prop   

    How does the new wing’s performance compare with the under camber wing? 89 mph is pretty good! The 503 in my model 1 drags it through the air at about 60 mph, straight and level, at about 5,700 rpms, or 90% power. That’s with a really draggy cabane gear and 25” Goodyears. No comparison to the Jabiru, I’m sure. Bob told me his model 4 cruised at 90 with the 670. He also said his model 1 flew slower, as in a lower approach speed or stall speed, and he preferred that plane. Maybe I missed a post, but how did the different wings affect performance on your plane? Are you happy with it, or do you consider switching back, for any reason?
    • 0