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older Electroair inition noise?

13brv3

Well Known Member
auto plug recommendation?- older Electroair inition noise?

Greetings,

The -3B I purchased has an older (purple) Electroair ignition, and I've been trying to eliminate some radio noise. I've been struggling with this for months now, and what I've determined is that it is RF noise that's broadcast, not wiring related. I can use a handheld radio and hear the noise, and moving the radio closer to the engine (reaching from the cockpit) makes the noise more pronounced. Turning off power to the EIS ignition 100% stops the noise.

It would appear that the high voltage ignition RF noise is not being suppresses, and that leaves the coils, wires, and plugs as obvious suspects.

The wires were the first thing replaced. The original wires were blue Taylor Spiro Pro 8mm silicone wires, with a special spring type insert for the plug end. First I cut the wires off an inch, and reterminated them, but that didn't help. Next I tried to order new wires, but bad timing (OSH) and the fact that the wires were out of stock was a problem. Eventually I ordered a universal wire set from Taylor, using the same 8mm Spiro Pro wire. Those were installed with the old plug spring fittings, but it didn't correct the noise issue.

The UREM37BY plugs had 160 hrs on them according to the logs, and looked OK, but I replaced them with new plugs gapped to .032". No change.

The plane used to have two of these EIS units, but a previous owner changed the left side back to a mag, though they left the unit bolted to the firewall. I had removed the unit, and I was able to use those coils to replace the ones on the working unit. Sadly, still no fix.

Electroair has a newer red set of wires, and a brand new adapter that converts the aircraft plug into a normal spark plug tower to eliminate the fiddly spring adapter. I'm waiting for confirmation that those are actually better suppression wires, and hoping they're in stock.

Has anyone else had this much trouble getting rid of ignition noise? I've had Lightspeed ignitions on two previous RV's, and never had any radio noise, so this is really getting frustrating.

Thanks,
Rusty (measuring RPM by the popping on the radio)
 
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Thanks, but I think I have it isolated well enough. I'm mostly curious if anyone has had to go to different wires or plugs to eliminate similar noise from their EIS. If anyone saw an improvement going from the older blue wires to the newer red wires, that would be nice to hear as well.

It seems odd that mag wires are shielded, but other spark plug wires are not. Is that to allow non-resistor plugs maybe?

Fortunately, the noise doesn't make the radio unusable, but it's an annoyance that I've put off for too long.

Cheers,
Rusty
 
I was referring to the bottom comment in the link where the guy switched to magnecor racing wires which he claims totally solved his noise problem.

Lightspeed ignitions are CDI and don't have near the voltage peaks an inductive ignition does. I was good friends with the original designer of the Lightspeed before he passed away a few years ago and discussed this at length with him.
 
I was referring to the bottom comment in the link where the guy switched to magnecor racing wires which he claims totally solved his noise problem.

My apologies. I got bogged down in all the RF sniffer talk and gave up before getting to the good part. The Magnecor CN wires do sound nice. For all I know, that might be the new red wires that Electroair offers. Still waiting to hear from them.

Thanks,
Rusty
 
I had this same issue with my electro air installation. Electro air can supply you with suppression ignition wires. The same wire they use on certified installations. The new wires took care of 90 percent of my problem. These are spiral wound wires designed specifically for RV suppression. I believe they are supplied by magnecore
 
That's good to hear, because for almost $50 each :eek:, I'll have a set of 4 tomorrow. The price seems to have nearly doubled either because they are PMAed wires, or because they now come with an adapter that screws onto the aircraft plug to give it a normal spark plug contact. Having recently stuck that spring thing into wires a number of times, that will be a welcome change. I guess you still have to make up one end, but it's with a normal spark plug boot and connection which is supposed to be easier.

They said they started using the red (new) wires for all the certified installations, and at some point the experimental kits will get them too.

In the interesting theory dept, an RF genius friend of mine suggested that you want to make sure and not make the wires 1/4 wavelength, since that will make them a better antenna. For the 125 MHz range I've been using for testing, that would be about 23.5". I'd bet I have cables close to that, and I'll make sure and avoid it when I make the new ones, just in case.

Cheers,
Rusty
 
My kit came with the blue solid core wires which we?re extremely noisy in the 10. Only the radio connected to the upper antenna had the issue. The cabin in the 10 is composite and did not block the upper antenna as well as the fuselage did for the lower antenna. I used a spectrum analyzer to troubleshoot the issue. Electroair replaced the wires for free.
I would not sweat the quarter wavelength issue with the spiral core wires, totally different situation than solid core wires
 
I got the new wire kits, but they needed to send some connectors separately. When I got those today, I headed to the airport to install them. Just as I got to the airport, I got an email saying NOT to install them. Sounds like they're having some teething pains with the new spark plug tower adapters. I'm sending their wires and adapters back, and will try autoplugs and maybe magnacor wires.

Speaking of auto plugs. Any known good suggestions for use with an IO-320 160HP?

Thanks,
Rusty
 
Thanks. I saw those mentioned somewhere else as well, so I'll give them a try.

I'm going to try the auto plugs with the Taylor Spiro Pro 8mm wires I have now, just because it costs nothing, and might work. Auto plugs often have higher resistance, so it won't hurt to try. If that still causes noise, I'll have to look for better suppression wires, like the Maganacor.

Rusty (make the noise stop...)
 
My experience has been that the noise will be reduced and be acceptable, but not completely eliminated. I'd like to get a spool of Magnecor wire to try.
 
EI EI O....

Thanks. I saw those mentioned somewhere else as well, so I'll give them a try.

I'm going to try the auto plugs with the Taylor Spiro Pro 8mm wires I have now, just because it costs nothing, and might work. Auto plugs often have higher resistance, so it won't hurt to try. If that still causes noise, I'll have to look for better suppression wires, like the Maganacor.

Rusty (make the noise stop...)

Rusty,
I bought one of Jeff Rose's first Electroair systems back in the early 90's for my 0-320A powered RV4 and used his stock automotive wires with Autolite 386 automotive plugs with no radio noise noted, ever. I avoided Aircraft plugs as the issues (and cost) outweighed the gains.
Additionally, Autolite 386's thread right into the cylinder and are so cheap you can discard them for new ones every year.

My HR2 (IO-540) and my RVX(0-360) also have early Electroair ignitions with ACCEL plug wires, Denso L-14U or A386 plugs and I've never had radio noise issues (although those jets get quieter every year:)).
FYI...

V/R
Smokey
 
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That's interesting. I didn't know you could even buy 18mm plugs anymore. Of course I've already ordered the adapters, so I'll stick with the 14mm plugs. How many hours do you get on a set? Just curious really, since there's be no reason to ever reinstall a used plug for what those cost.

Cheers,
Rusty
 
I've tried the 386's in the past and found them to be too hot. Would get dieseling on shutdown, electrodes would wear relatively quickly, and would get occasional misses. You can certainly try them but I wasn't happy with them. After going to the adapters I tried BR8ES and they were better, but the BR9ES plugs being a step colder work great.
 
My experience has been that the noise will be reduced and be acceptable, but not completely eliminated.

This is completely accurate. I installed the auto plugs, and reterminated the Taylor Spiro Pro wires yesterday. A quick test shows noise so low that you'd never hear it if you didn't know what to listen for.

I meant to measure the resistance of the aircraft plugs, but I did measure the auto plugs at about 4500 ohms. The Tempest plugs allow a range of 500-5000 ohms, and I'm betting they're close to the 500 end.

Thanks for the comments!
Rusty
 
Good to hear.

Aircraft radios generally have an amplifier gain circuit that turns up the gain on weaker transmissions (usually 100+ miles away) and you will hear more noise in those cases. Otherwise its fine.

I've been wanting to try Magnecor wire but I still have a spool of Taylor wire.
 
I have mild problems of the same nature with my RV7 and Electroair system (same set up as yours: one EI+1 impulse mag). Be nice to know if the red set of wires makes the problem go away.

Very interested.
PS I had no luck getting a response from the factory 3 weeks ago trying to get new coils. So I bought 2 from Electromotive (same coil with a different lable).

Electromotive may also have the new red wires...
 
This is from Magnecor's web site!
KV85 COMPETITION CABLE CN25 SERIES 8.5mm

Features Magnecor's exclusive 2.5mm Metallic Inductance Suppressed CN25 conductor, consisting of a special alloy wire precisely wound at 200 turns per inch over a ferromagnetic core. This ignition cable is specifically designed and constructed to overcome the severe RFI problems associated with low-resistance spiral conductor ignition cables, ever-failing carbon conductors and the need for additional suppressors, making it an ideal choice for land and water vehicles in which Ham radios, telephone and TV equipment, 2-way radios, off-shore communication equipment, and high powered sound equipment etc. is installed. High capacity conductor eliminates the spark energy reduction associated with all "suppression" ignition cables and supplementary suppressors normally used to solve severe RFI problems. Entire jacket made from aerospace extreme heat-resistant silicone rubber.
 
I continue to be happy with the auto plugs and the blue Taylor Spiro Pro wires, so I won't be trying any new wires.

Cheers,
Rusty
 
You can purchase the red wires direct from Magnecore. Like I said in an earlier post, they eliminated 90% of the noise. When you install the EI system, you need to keep the wires separated in wire looms. You should not bundle them together
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