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-   -   ElectroAir/Jeff rose (https://vansairforce.net/community/showthread.php?t=122690)

Boyd Birchler 02-12-2015 08:04 AM

ElectroAir/Jeff rose
 
I had a half coil failure on my 11 year old Electroair EI. It would fire only one of the two wires connected to the "B" coil. Since it fires on every up stroke (lost spark system fires on the exhaust as well as the power stroke) I switched cylinder 3 and 4 wires as a test: the bad firing followed to the opposite cylinder.
All of this was easily observable on the engine analyzer. If the magneto was operating and the EI (so that both systems were on) the indication was a 300F increase in EGT and a 50 decrease on CHT. If you run it only on the bad performing EI: both EGT/CHT would go cold in the 250F or less on the bad coil post.
I was lead to believe a Delco D555 automotive coil would be a direct replacement however the internal clips would not accept the 2 flat brass prongs or let the coil slide on. This may be a change by Delco of the internal clips over the years.

The equivalent MasterPro coil sold at O'reilley Auto parts PN#2-5192 or E51 will slide on the prongs easily.

That is where I'm at right now. I have not run it yet as the wind was blowing last night too hard to try to open the hangar.

cajunwings 02-12-2015 09:55 AM

Electroair
 
Please post your results when you are back up and running. Thanks

Don Broussard

RV 9. Rebuild in progress

smokyray 02-12-2015 10:22 AM

Looks like a duck..
 
Quote:

Originally Posted by Boyd Birchler (Post 958580)
I had a half coil failure on my 11 year old Electroair EI. It would fire only one of the two wires connected to the "B" coil. Since it fires on every up stroke (lost spark system fires on the exhaust as well as the power stroke) I switched cylinder 3 and 4 wires as a test: the bad firing followed to the opposite cylinder.
All of this was easily observable on the engine analyzer. If the magneto was operating and the EI so that both systems were on the indication was a 300F increase in EGT and a 50 decrease on CHT. If you run it only on the bad performing EI both EGT/CHT would go cold in the 250F range or less on the bad coil post.
I was lead to believe a Delco D55 automotive coil would be a direct replacement however the internal clips would not accept the 2 flat brass prongs or let the coil slide on. This may be a change by Delco of the internal clips over the years.

The equivalent MasterPro coil sold at O'reilley Auto parts PN#2-5192 or E51 will slide on the prongs easily.

That is where I'm at right now. I have not run it yet as the wind was blowing last night to hard to try to open the hangar.


Boyd,

It should work. Having had three Electroairs on 3 different airplanes, purchased the first from Jeff himself in 95". I only had one coil fail and I used a Lexus replacement. It too plugged right in. Btw, I'm running a PMag in unison with my Electroair, dual EI.

My Electroair"s have always worked great but like Forrest said " like the P-Mag a lot"

Smokey

Boyd Birchler 02-12-2015 12:44 PM

Electroair/Jeff Rose
 
I suspect the ignition wire on cylinder #4 caused the failure or perhaps the wire that proceeded it. The wire was obviously replaced with a standard automotive suppression, soft conductor wire. All other wires were the original Taylor spiro wires that, while also suppress ignition noise, have only 1/10th the resistance of normal suppression wires. This could be a co-incidence or a cause, I do not have enough information to make a good conclusion.

mosquito 02-12-2015 01:46 PM

Quote:

Originally Posted by Boyd Birchler (Post 958669)
I suspect the ignition wire on cylinder #4 caused the failure or perhaps the wire that proceeded it. The wire was obviously replaced with a standard automotive suppression, soft conductor wire. All other wires were the original Taylor spiro wires that, while also suppress ignition noise, have only 1/10th the resistance of normal suppression wires. This could be a co-incidence or a cause, I do not have enough information to make a good conclusion.

If your fix proves problematic, I have an older (2002-ish) coil pack with ~100 hours on it in some dark corner of my hangar.

-jon

Boyd Birchler 02-28-2015 02:20 PM

Half coil failure
 
WX has been 30 or more degrees cooler than average for INDY for the past month, some days the high has been below "0". For that reason it took nearly 3 weeks before I could flight test with the new coil and the new wire. It ran perfect!

Prior to this I often saw a rise in EGT on cylinder 4, it would come and go. I did not worry too much about it because the CHT was always well within range. The EGT rise was likely caused by intermittent failure of the coils out put to plug/wire #4. It took a complete failure of this half of the coil to make it apparent that was causing the problem. The problem is now solved.

Glas467 03-01-2015 08:41 PM

Great info, I also have an original '95 vintage Electroair, still going strong.

Reggie


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