IO-540 Ignition

I posted this in the Engines section but got no response, so trying here.....

I have a stock IO-540 D4A5 built by Aerosport. I am close to starting her up and have no faith in Emag having their P200 ready in time - despite their website saying it is "close". So, I am researching conventional mags.

Here is what I have found:

- Slick kit K6536 - left mag 6393, right mag 6350

- Left mag has retard breaker

- I need a Slick Start

- I have to add the jumper to the start switch to ground the right mag during start. I do not need to ground the advance breaker on the left mag as this is taken care of by the Slick Start

Is that all correct? Also, there are various choices of colour of harness and type of plug (fine wire or massive). What's the deal with that? What would you recommend?

Before anyone starts recommending other types of electronic ignition, let me stop you. In UK, only Pmags are authorized for dual installation and I don't want to go with a single and don't want to get involved with all the mods that are required. Researched it all - Pmags are what I want but it's very much touch and go.........

I'd say everything you posted is correct.
I'm surprised your engine didn't come with plugs and harness(?). Yes, some harnesses come in different colors. I think most people are running massive electrode plugs.

A couple of quick thoughts.

1. I was about where you are 3 years ago and also wanted the Pmag system and was assured it was just a few weeks out.

2. The Bendix 1200 mags fit nicely in the RV10 and Monte Barrett told me directly that those are what he would personally use. Plus you don't need the slick start.

The engine would have come with everything installed but I asked not because the P200 was supposed to be available "soon". Now I am having (miracles not withstanding) to retrofit the entire ignition system.

Anybody any further comments on what plugs/harness colour to use?

I have dual mags on mine: Left mag is a 6351 impulse coupled and right is 6350 non-impulse. I do not have a Slick Start set-up and have no need for one. Its EZ starting hot or cold using proper procedures. I have massive plugs also. No way I will spend $100+ for a fine wire. Choose your harness color to suit your desires. I used white on my old C-152. They looked great,,,,for a while.

http://www.vansairforce.com/community/showthread.php?t=102709&highlight=Slick+540+service+bulletin
Consider exchanging the impulse coupled mag with a slick start module and you won't have to be concerned about the 250 hour service bulletin.
It does not matter if you have a newer version all impulse couplings are affected with your engine.

OK, think we are getting there. I didn't realize that the harness colour was purely cosmetic! Duh........

My research also showed that the left mag was a retard breaker not impulse - or is it optional?

I also understood that the Slickstart was more or less mandatory.

Most engines are coming out with a retard breaker mag, because of the onerous SB on the Slick impulse mags.
Retard breaker mag - you need Slick start to insure a spark at low rpm.
Impulse mag, whether Slick or Bendix, no Slick start needed.

Thanks - got it.

One more thing, if I may. Spark plugs seem to come in 2 flavours - -38 or -40. What's the difference/recommendation?

You know when you expect the worst at an airport, load up extra fuel, lots of contingency planning and you get there to find the place wide open, no1, high speed all the way? Happened to me last week in JFK after the snow. Maybe that's what will happen with the P200.......

When I switched to a Lycoming in my RV-8, the engine I bought came with Bendix 200 series mags. The left one has the retard breaker, and uses a starting vibrator. This is my first experience with retard points and vibrator, but I sure do like the way it starts. Shower of Sparks outperforms an impulse coupling.
In my case, I had to research the connecting wiring. I used 2 toggle switches and one automotive 'black ice cube' relay to switch the mags and a push button to energize the starter, the vibrator and the relay.
So I can't help you with the Slick brand, but I can encourage you about the benefits of retard points and starting vibrator.
As for the 38 and 40 spark plugs, my engine came with the 38 heat range. It had previously served in a Brantley B2B helicopter where it ran hard and hot. These plugs fouled on me during initial ground running before the first flight, they ran too cool with the idling and taxiing. I installed a set of UREM40 plugs and it's been fine.

Thanks everyone - think I now have the info I need

Looks like I need another bit of info. Do Slick mags come with a RPM sensor fitted? I see in Aircraft Spruce, the Hall effect sensors are pretty pricey but they say "replacement"

If not, I assume you can sense the high volt output?

paul330 said:

Looks like I need another bit of info. Do Slick mags come with a RPM sensor fitted? I see in Aircraft Spruce, the Hall effect sensors are pretty pricey but they say "replacement"

If not, I assume you can sense the high volt output?

Click to expand...

No. My RPM sensor came with the sensor package associated with my EFIS. In my case a UMA T1A9-1 for my Garmin G3X. Best answer is to get with whomever made your Tach, whether it be digital or analog, and see what they recommend as the solution may not involve the mags at all.

I have the same engine with a Slick mag on the left and Lightspeed on the right. Starts first time every time. Almost no mag drop on the Lightspeed alone, it is very efficient.

My sensor package from Advanced Flight included an rpm sensor that screws into the side of the Slick mag.

Thanks again.

I have Skyview and they don't do a RPM sensor. The manual shows how to use a straight pick off from the P-lead with a resistor. Think I'll try that before forking out $$$$$.....

Sounds like you have what you need but just for info, I also have a D4A5 with Slicks... I have no impulse coupler nor a slick start vibrator and it starts fine with massive electrode plugs.

I had a lot of trouble with the p-lead pickup recommended by the SkyView install. I have a single Slick plus Electroair. In order to analyze the problem, I purchased a portable digital sampling oscilloscope and captured p-lead waveforms in flight.

What I found was a complex, variable amplitude waveform that depends on external factors... Compression ratio, Cylinder number RPM, MAP, plug gap etc. a 'one size fits all' resistor value did not work.

Since I get juiced by solving technical problems, I decided to develop the P-TACH magneto p-lead pulse stabilizer. (see link).

I posted the design as an Open-source project, but it can procured as a completed device. I think the variable reluctance sensors that mount to the magneto are fine as well, as long as you want to run the wires.

Something this simple shouldn't be so complicated and 90% of installations don't seem to have probems. The rest of us have that odd combination of circumstances that require help.