 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
dougwitkowski(at)netscape
Guest
|
 Posted: Mon Aug 19, 2013 7:10 am Post subject: [Pulsar-Aviators] New Stator Coil In - Flying Again |
 |
|
Common knowledge is that ignition systems fail on shutdown (possible voltage spikes??). Testing pre-shutdown probably won't help, the testing itself may cause the failure. In my mag check procedure, it's not the RPM drop that's important, it's the return to normal RPM on 'both' that is important.
--
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
 |
barryjedwards(at)btintern
Guest
|
| Posted: Mon Aug 19, 2013 7:28 am Post subject: [Pulsar-Aviators] New Stator Coil In - Flying Again |
|
|
Some years ago, following a 20 mile sea crossing, when I touched down at my home base, I did, as always a mag check and found one mag was not working. It was working when i did the pre take-off check. I ALWAYS check my mags before shutdown for the very reasons Ron was saying: better to find out before you leave the airfield, than the next time you want to fly!
Barry
G-XPXP 012 Taildragger
UK
From: dougwitkowski(at)netscape.net (dougwitkowski(at)netscape.net)
Sent: Monday, August 19, 2013 4:06 PM
To: Pulsar-Aviators(at)yahoogroups.com (Pulsar-Aviators(at)yahoogroups.com) ; Pulsar-List(at)matronics.com (Pulsar-List(at)matronics.com)
Subject: Re: [Pulsar-Aviators] New Stator Coil In - Flying Again
Common knowledge is that ignition systems fail on shutdown (possible voltage spikes??). Testing pre-shutdown probably won't help, the testing itself may cause the failure. In my mag check procedure, it's not the RPM drop that's important, it's the return to normal RPM on 'both' that is important.
-----Original Message-----
From: Ron Koval <ronko11(at)yahoo.com>
To: Pulsar Builders <Pulsar-List(at)matronics.com>; Pulsar-Aviators <Pulsar-Aviators(at)yahoogroups.com>
Sent: Mon, Aug 19, 2013 9:50 am
Subject: [Pulsar-Aviators] New Stator Coil In - Flying Again
Pulsar Friends,
Put in the new stator coil in my 582 and ran it through 4 rounds of touch and goes Sunday evening. Relief ... the Pulsar and I are looking forward to the convention.
After this experience, I learned and added a step to my engine shut down procedure, do a mag check. It is nice to know that you completed your flight with both mags still working and if one ignition circuit, perhaps fails, due to everything under the cowl at high temperatures, it is nice to know. Also if this were perhaps the flight that one ignition circuit fails (more likely to fail engine running than in the hanger), it is better to know now rather than on the ramp wanting to take off per plan.
I discovered that in my defective stator coil there were 2 intermittent connections, right at the rubber 2 conductor connector of my defective stator coil. I am on a mission to find out where the other side charging coil is open. It would be nice to discover that it also has a simple connector wire problem and not an open within one of the 2 coils that make up the charging circuit.
Even after taking extra care to clean all of the contacts (grounds, power ..) putting everything back together with the new stator coil, my analog tach is reading way high. Fortunately my digital tach is what I reference. Last time I fixed it, I added a stainless steel external tooth lock washer on the heavy ground to dig into the metal surfaces and provide a good connection to the engine block (but I cleaned this terminal again and still have the lock-washer in place.
Looking forward to the convention.
Ronko
__._,_.___
Reply to sender ([email]ronko(at)att.net?subject=Re%3A%20New%20Stator%20Coil%20In%20-%20Flying%20Again[/email]) Reply to group ([email]Pulsar-Aviators(at)yahoogroups.com?subject=Re%3A%20New%20Stator%20Coil%20In%20-%20Flying%20Again[/email]) Start a New Topic Messages in this topic (1) Recent Activity: Visit Your Group
Text-Only ([email]Pulsar-Aviators-traditional(at)yahoogroups.com?subject=Change Delivery Format: Traditional[/email]), Daily Digest ([email]Pulsar-Aviators-digest(at)yahoogroups.com?subject=Email Delivery: Digest[/email]) • Unsubscribe ([email]Pulsar-Aviators-unsubscribe(at)yahoogroups.com?subject=Unsubscribe[/email]) • Send us Feedback ([email]ygroupsnotifications(at)yahoogroups.com?subject=Feedback on the redesigned individual mail v1[/email])
.
[img]http://geo.yahoo.com/serv?s=97359714/grpId=13031253/grpspId=1705786083/msgId=5646/stime=1376923751[/img]
__,_._,___
[quote]
href="http://www.matronics.com/Navigator?Pulsar-List">http://www.matronhref="http://forums.matronics.com">http://forums.matronics.com
href="http://www.matronics.com/contribution">http://www.matronics.com/c
[b]
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
dougwitkowski(at)netscape
Guest
|
| Posted: Mon Aug 19, 2013 8:12 am Post subject: [Pulsar-Aviators] New Stator Coil In - Flying Again |
|
|
A failed igniton should show up as a reduced performance, ie. more throttle for the same speed. And it should show as higher EGT's and possibly higher water temps. Both coils fire at the same time but if one is not working, the cylinder is running essentially with retarded spark. If you did not observe this, both systems may have been working and the one failed when you did your test. I must admit, though, that I have never tested the plane in-flight with one mag only, to see how it acts.
If you switch to mag 2, mag 1 is grounded. Mag 1 could fail during the test and would show up as failed when you switch to mag 1. If the engine dies on the first mag that is tested, then it was failed during the time of running. (I am thinking of the typical 'mag 1 / mag 2 / both / start' switch)
Not saying they don't fail in flight, just that it's not the common mode of failure.
--
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
ronko(at)att.net
Guest
|
| Posted: Tue Aug 20, 2013 11:22 am Post subject: [Pulsar-Aviators] New Stator Coil In - Flying Again |
|
|
Doug,
Forgive me for not having heard, ignition systems fail on shutdown. I find that very hard to believe, understanding how they work and how we shut our ignition down for mag checks.
In our CDI ignition system the stator coil charges up a capacitor, then a second coil triggers an SCR (solid state device; silicon controlled rectifier) and discharges the capacitor into the ignition coil which has a step up winding that fires the spark plug. All we do to shut this down is ground the very front end of the process, by grounding the stator coil so no charge is provided to the module that houses the capacitor. Lycomings, Continental engines do the same except, they use the magnetic field of mag coil, open a set of grounding points, which produces a sudden magnetic field change, which then causes current to flow in the primary coil, and the secondary coil step up winding fires the spark plug. They also, at the front end, ground the primary coil using the P-lead to disable ignition. The only thing that is getting beat up during a mag check is the mag switch.
Our ignition systems are not very susceptible to spikes or noise, because they are the worst source, the culprit of the greatest transients and noise in our aircraft.
With the faults that I have found at the connectors coupling the wires from stator coil to the CDI module, the most likely root cause is vibration mechanically breaking the wire at the connector. I have one more side of the stator coil to find out where it broke down. I am very anxoius to find this other fault and protentially be able to fix it and have a back up stator coil.
Best regards,
Ron
From: "dougwitkowski(at)netscape.net" <dougwitkowski(at)netscape.net>
To: Pulsar-Aviators(at)yahoogroups.com; Pulsar-List(at)matronics.com
Sent: Monday, August 19, 2013 10:06 AM
Subject: Re: [Pulsar-Aviators] New Stator Coil In - Flying Again
Common knowledge is that ignition systems fail on shutdown (possible voltage spikes??). Testing pre-shutdown probably won't help, the testing itself may cause the failure. In my mag check procedure, it's not the RPM drop that's important, it's the return to normal RPM on 'both' that is important.
--
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
dougwitkowski(at)netscape
Guest
|
| Posted: Wed Aug 21, 2013 8:16 am Post subject: [Pulsar-Aviators] New Stator Coil In - Flying Again |
|
|
Ron,
Great discussion!
I assumed that failure on shutdown was 'common' knowledge as it was told to me by both Green Skys and Leading Edge folks. Never really delved into the 'why' of how the failures are claimed to happen.
You are probably right in that it's not a voltage spike. More likely stresses caused by the grounding action.
The charging coil will experience a mechanical jolt and a momentary high current flow when the coil is grounded. That could fatigue the coil or chafe the insulation.
There is also a bridge rectifier between the charging coil and the capacitor. It has to hold back the voltage as it's built in the capacitor with each charging coil pulse. Even at the zero voltage point, there is resistance in the charging coil. When the coil is grounded, the rectifier has to hold back what could be a full charge (before the system fires the plugs) against a zero resistance short. Either of these scenarios could be the cause of a 'failure at shutdown' situation.
I doubt the capacitor or the SCR would experience any stress from the grounding.
Keep up the discussion at LWC, I'm sure it will be very interesting.
Doug W
--
| | - The Matronics Pulsar-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Pulsar-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
