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Tracy,
OK, confession time. ;-)
Ref. #1 - The wires are about 5 ft from EC-2 to coils, but could be shortened by a foot or so if that would help. As for wire routing, everything is bundled together, but I am now in the process of fixing that mistake. I plan to route the injector leads out through the firewall in a separate bundle. Same goes for the coil trigger leads.
Ref. #2 - Power ground wires were bundled in with the rest (A,B,C & D), but for only about a foot down near the coils. I've since removed them from what is left of the bundle. They are now about 2" long and connected to the coil mounting bolts/bracket. There are two ground wires running from the coil bracket to the engine block (shares bolt with ground strap).
Ref. #3 - Yes, power leads share common bundle and are not twisted pairs.
Ref #4 - With all the extra room in the existing bundle, I could easily change to twisted pairs. I'll wait to do this until the other items are done.
Ref #5 - Yes, injector leads are in the same bundle, but will be removed from the bundle and re-routed. (See #1)
Alright, so what did I do right? After reading your response, I guess its no wonder that it ran at all. Hopefully, the newbies will take heed and follow Tracy's suggestions to the letter.
Mark S.
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From: Rotary motors in aircraft on behalf of Tracy Crook
Sent: Sat 10/14/2006 10:02 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Latest EC2 updates, Installation notes
Opps, signed off too quick to catch that Mark. Below is what I wrote to Bob Darrah on the subject. Have not heard back from him yet. I am surprised that there is any cross-talk in the harness as the GM harness does not seem to have this problem in the car. The harness in the plane is either much longer or something else is going on.
Need a few details on harness routing to answer your question.
1. How long is the wiring harness between EC2 and coils?
2. How is the power ground to the coils (A terminals) routed? (hopefully not in the same harness, if so, there is your problem).
3. Same question as 2. on the power terminals.
4. I would be surprised if this turned out to be the problem but if coupling between the control lines themselves (C pins) turns out to be the problem, use either twisted pairs or shielded wires to drive the B & C lines to each coil. I would lean toward twisted pairs.
5. Are there any other lines routed along with the coil harness (injector drives, etc)?
Tracy
----- Original Message -----
From: Mark R Steitle <mailto:mark.steitle@austin.utexas.edu>
To: Rotary motors in aircraft <mailto:flyrotary@lancaironline.net>
Sent: Friday, October 13, 2006 4:39 PM
Subject: [FlyRotary] Re: Latest EC2 updates, Installation notes
Tracy,
Before you sign off, can you shed some light on my previous post concerning cross-firing of the coils and what to do abou it?
Thanks,
Mark S.
________________________________
From: Rotary motors in aircraft on behalf of Mark R Steitle
Sent: Mon 10/9/2006 8:31 AM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Latest EC2 updates, Installation notes
OK, I'll chime in here. After reading Bob Darrah's post last week where he noticed a big improvement after separating the leads to his coils I gave it a try on my 20B. It made a big difference, but was most noticeable in the lower rpm range. I was only able to separate the wires down near the coils, and then only by a small amount, but it made a substantial improvement. My question for Tracy is, can I leave the grounds and +14v wires bundled together and only separate the trigger leads, or do I need to separate all the wires? Also, if I were to use 3 individual shielded wires and ground the shields, could I then bundle the trigger leads together with the rest of the coil wires?
On a side note, after separating the coil leads, it took a much leaner mixture to get it to run smooth. Before, the best it would idle was about 1200rpm, now it will idle nicely at 900 rpm, not that I want to do that, but it shows that the improvement isn't all in my head.
Mark S.
________________________________
From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Wendell Voto
Sent: Saturday, October 07, 2006 11:08 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: Latest EC2 updates, Installation notes
Tracy,
Would shielded cables be okay to run close together in a fiberglass aircraft?
Thanks,
Wendell
----- Original Message -----
From: Tracy Crook <mailto:lors01@msn.com>
To: Rotary motors in aircraft <mailto:flyrotary@lancaironline.net>
Sent: Wednesday, October 04, 2006 9:31 AM
Subject: [FlyRotary] Re: Latest EC2 updates, Installation notes
While trouble shooting Al Gietzen's EC2 engine controller problems, he mentioned that he was seeing relatively large mixture changes when the alternator was switched off and the battery voltage went low. The mixture goes leaner with lower battery voltage because the injectors take longer to open. It was well within the range of the manual mixture control to correct but it got me to thinking about adding battery voltage compensation to the EC2. This has been done and all controllers shipped after 9-20-06 now incorporate this feature. Not a freebie, but if anyone wants this incorporated into an earlier EC2 it can be retrofitted.
The other update is a rev limiter. It was easy to do so I went ahead and added it. I haven't seen this as a priority because in our application if you make use of it, it means that you need to be more concerned about the pilot's health than the engine's (the prop has fallen off the airplane). The default rev limit is 8000 rpm. If you want something different, specify when ordering. (Also retrofittable)
EC2 / EM2 Installation Note.
This only applies to EC2 engine controller installations combined with early two-part EM2 engine monitors in canard aircraft where both units are installed near the engine and have long wiring harnesses connecting them to the EC2 front panel and EM2 display (a rare combination that may be unique to Al's airplane). Have been working with Al for some time searching for the cause of random MAP table and other EC2 parameter corruption. I am now almost certain that the cause is noise coupling from the EM2 display harness into the EC2 control panel harness. The two harnesses were laced together in Al's installation. He is in the process of separating them now (sympathies to Al, no picnic). Needless to say at this point, never run these two harnesses together and separate them as far as practical. I think Al will have about 4 inches between them when separated.
Tracy Crook, RWS
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