Mailing List flyrotary@lancaironline.net Message #16968
From: Paul <sqpilot@bellsouth.net>
Subject: Re: [FlyRotary] To Paul SOme diagnosis thoughts was Re: [FlyRotary] Re: Microtech EFI and Tuning
Date: Fri, 11 Feb 2005 12:21:17 -0600
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Hi, Leon....I appologize for being late in responding....I haven't had a chance to get on the computer.  Yes, I ran the engine yesterday. After inspecting the spark plugs (looked like new with no evidence of rich soot or burned porcelain), I fired it up and it ran great. Good idle, midrange, and 5300 rpm static instead of my usual 5200 rpm. I ran it WOT until the temps finally got so high that I had to shut it down and watch the antifreeze burp out of the overflow on the surge tank.  Set up a cooling fan for a few minutes, then restarted the engine and temps came down right away with the circulating of the water/antifreeze through the engine and radiator.
     As I mentioned in my previous post, I am higly suspect that my problem was vapor lock/heat related due to the two close together WOT engine runs I performed just prior to takeoff. Normally, I always take off with temps around 160 to 180, not 220 or better. My temps normally come down in the climb, but at only 250 feet, I'm fairly confident I hadn't gotten much cooling air to the radiator at WOT in the climb.  I will keep you posted. Thanks again for taking the time to help out.  Paul Conner
----- Original Message -----
From: Leon
Sent: Wednesday, February 09, 2005 1:07 PM
Subject: [FlyRotary] To Paul SOme diagnosis thoughts was Re: [FlyRotary] Re: Microtech EFI and Tuning

Hi Paul,
 
I've just been thinking.  (A most dangerous exercise for me @ 4:30 am in the morning!).  As I mentioned previously,  I don't think the "fan out" had anything to do with the ECU itself.  Reading your posts,  it looks like you have got a bit of a handle on tuning anyway,  with mention of running the aircraft up against your van,  and fiddling with the mixture while watching the EGT etc.  I assume you have disabled the rev limiter function on the Microtech??
 
From what you tell me,  it looks like it's a nightmare to remove the engine.  Seeing you have flown successfully for over 9 hours already,  then the engine obviously has sufficient grunt to keep the aircraft airbourne.  Probably a waste of time & money getting this engione dyno'd.
 
So if you are having another engine assembled with high comp rotors,  I'd wait until then.  There is no reason why you couldn't leave the engine plate on the engine though.  From what I have seen,  the plate is mounted onto the frame with just 4 mounts??  If you find a friendly engine dyno place,  then do get the new engine dyno'd.  You will then know exactly how many BHP the engine has at what RPM,  and can then probably get the prop size right first go,  and as a bonus,  you will have the confience in knowing that the mixtures are correct.
 
Anyway,  back to the present conundrum.  Many many years ago,  when teaching me to diagonse engine faults,  an old mentor once said to me that if an engine has approximately the right amount of fuel,  and a decent fat spark at approximately the right time,  then an engine will run and produce a reasonable amount of power - unless there is something mechanical wrong with the engine itself.  
 
Rotaries are particularly forgiving in that they will run on a pretty wide mixture range,  and are relatively insensitive to timing,  (except under boosted conditions),  and there are only three basic things that will kill a rotary mechanically - loss of oil (I can see Rusty nodding his head!),  loss of coolant,  or swallowing something solid.
 
The trick is to now systematically work down through your "fan out" episode to see why it quit.  Whatever you do,  DON'T jump to any conclusions. Assume nothing,  and check everything.  Have you tried to start it since?  Will it run??  Basically,  when I have a problem like this,  the first thing I check is ignition,  (because it's easy,  and immediately eliminates 50% of the options if I get a jolt from a coil lead!!).
 
I know this might sound facile,  but obviously if there is no spark,  you go and find out why. A blown fuse,  dud relay,  loose wire somewhere,  faulty switch  etc.  If you do have spark, then the problem is most likely fuel supply.  Fuel tank selector first (My mate Ed turned his RV into a glider one time simply because he didn't have any fuel in one of his tanks!). 
 
I also know of a certain experienced aerobatic pilot over here who is now in a wheelchair because he didn't have the fuel selector positively set to the correct tank.  The selector was half way between tanks,  and while it had enough fuel supply to do the "run-up",  it didn't flow enough fuel for WOT  at take-off.  The ineveitable,  happened,  the engine quit around 200 ft, he tried to turn back,  it stalled and fell on it's tail,  and he's now in a wheelchair.  He also totalled a really nice aircraft.
 
If there IS fuel in the tank (yeah, yeah, ... I know,  I know, ...  but it's REALLY easy to check,  and it HAS happened before - remember the historic Boeing 307 Stratoliner that became a submarine in Elliot Bay Seattle?? - so even the pros are not immune to this!!),  and the tank selector is correctly selected,  then filters,  then water in the fuel,  then fuel pressure,  tank vents,  crimped hoses  etc.    It's a bit like a game of 20 questions (Ever played "Animal,  Vegetable or Mineral"??).  The Name of this game is "Igniton,  Fuel,  or Mechanical".  You try to eliminate about half of the causes at each step,  commencing with the easiest options.
 
So don't give up on the EFI just yet.  I can tell you that having played with carburettors for 30+ years,  I prefer EFI anyday. It's a mindset thing.  Carburettors also have their downsides,  and are subject to all the same fuel supply issues as EFI.  (Fuel quality,  water in the fuel, filters,  pumps,  lines,  tanks etc)  One major one that is a rarity with EFI is flooding.  Ask poor Ken Welter.  "Kentucky Fried" his Coot to a crisp some time ago. 
 
Anyway,  that's my little velvet bag full of Downunder pearls for today.
 
Cheers,
 
Leon
----- Original Message -----
From: Paul
Sent: Thursday, February 10, 2005 2:12 AM
Subject: [FlyRotary] Re: To Paul Re: [FlyRotary] Re: Microtech EFI and Tuning

Hi, Leon thanks for taking the time to go into such detail (as is customary for you) regarding suggestions for tuning my engine, etc. I took no offense with your comments. I would never be upset that someone is looking out for me.  Removing the engine, coils, ECU, handset, exhaust, etc would be labor intensive, as the coils are mounted on the firewall, the wiring for the ignition and handset go all the way from the firewall to the instrument panel in a narrow center console that took hours to "snake" the wires through, (engine is in the rear, and panel is in the front on a pusher) the handset is hard-mounted to the instrument panel, and the engine is mounted with an aluminum plate sandwiched between the oil pan and block, so removal would require reassembling the pan, shortening the oil pickup tube so that I could install the pan without the 1/2" thick aluminum spacer, my water pump has -16 AN fittings welded to it, so the dyno tuner could not use radiator hoses, and a host of other tasks, which while not impossible, are very time consuming to say the least.  I would gladly pay a lot of money for someone to do it on site. (mobile tuners). 
     As far as the fuel tank debris is concerned, that is a well known fact amongst the canard community.  I am fortunate that my fuel strakes are different from other fiberglass canards, in that they are already completely formed by the factory, (a top and bottom), with fuel tank openings already installed prior to installing them, so there is no drilling, sanding or fabricating, just glassing the top and bottom together on the fuselage, and that is all done on the outside of the fuel tanks. I still, however check my fuel filter screen, just in case. So far, nothing.
     Thanks again for all of your valued input and suggestions.  I have not totally given up on the MicroTech....just considering my alternatives, and as they say, it costs nothing to do your homework.  Yes, I was lucky to get the aircraft (and myself) safely back to Earth in one piece. I don't care to repeat that excercise any time soon....I am going to pull the spark plugs today and take a good look at them, and start my trouble shooting expedition.  Take care, and thanks again for your valued input.  Hey....if you'd like a mini vacation in the states, we'd be happy to put you up and buy you steak and lobster....
      Paul, I'm so confused, Conner


No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 265.8.6 - Release Date: 2/7/2005
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.300 / Virus Database: 265.8.7 - Release Date: 2/10/2005
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster