Friday, August 29, 2014

Making Progress Ain't Always Easy

I am drawing near, but Murphy's Law is omnipresent.

I was finally able to do my annual inspection and wrap this project up.  (What a patient wife I have). I use a seven page checklist to make sure I hit everything.  I finally got into the tail area to install a new battery and to look things over back there.  I used Jerry Marstall's nifty tail cradle, and it worked just great.  I wish I had one of these 20 years ago. As a bonus, when you are done with it, it folds down and you can store it up against a wall in your hangar.  You can get Jerry's plans somewhere at Quickheads

Toward the end of the annual I wanted to do a fresh weight and balance and I was able to borrow a set of calibrated scales from AvTech. Through all of that work, the plane only gained three pounds.  I'm satisfied with that.

I finally signed off the annual and took it around for a taxi spin. It was nice to have it all in one piece with all the electronics installed.

I really thought I was going to be able to fly. The other day I taxied out the full mile to the long runway at KMDH. Did my run-up and found the electronic ignition, which feeds the bottom plugs to be very rough.  What the F?  It was fine when I left the hangar. I figured it was a fouled plug and that it should clear up once I was in the air (the mag was running fine), but then I thought better of it and taxied back to Hangar 27.

One problem with a newly overhauled engine is the piston rings haven't seated yet and there can be excess oil in the combustion chamber until things settle down.  This excess oil can also foul spark plugs.

So I cleaned the plug and fixed a couple of other engine squawks I found that could cause oil leaks.  I am condensing this write-up, but all of this seems to drag on for days.  I can't say for 100% certainty is if a spark plug fouling issue, or if it is an electronic ignition problem.

Yesterday I gave it another shot.  Taxied the mile out again, was first in position and damn!  Rough engine on the electronic ignition again.  Really rough.  Since the magneto side was running fine, I did a high speed run down the runway to try and clear it, but no joy. Back to the hangar.

In a positive note while doing all this taxing, I found the plane is handling on the ground really well, better than before.  I attribute that to the care I took in doing the Gall Alignment, by the book. I used David's calculations to establish toe-out and camber.  So far, I'm quite pleased with the handling. For more info, see this post:

As if the ignition problem wasn't enough, when I got back to the hangar I found this.  Rats!

I have this custom aluminium oil tank and it seems to have developed another crack. It ain't easy being Experimental. I have a talented fellow available that can repair it, I hope this weekend.  When it's done I am going to heat treat it.  I am reading up on the process, but it involves heating the tank up to 700 deg. F, then quenching it with water.

So, today I'm going to throw in fresh set of automotive plugs and see it it helps the ignition miss issue. After I've done that, it's time to drain the oil.

As always, stay tuned....

EDIT:  I replaced the lower plugs and it ran just fine.  Whew!

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