6

6 Gun

Well Known Member
Trying to figure out the best way to run autoplugs on a slick mag using harness has any one got a way to crimp autoplug ends and use auto boots on the slick wires? If not able to figure it out I will look at 8.5mm auto wires.
Thanks Bob
 
wires

Thanks Dave for reply I knew about g3i and that's an option ,but I'm looking for a homebuilt way first and wanted to check with everyone to see if its been done before and if info is already there.
Thanks Bob
 
Bob,

What David is saying to you is, Thomas at G3i does exactly that.

Even if you don't use the MSD amplifier, the technique of installing the spark plug boots for auto plugs onto aircraft wires is the same.

BTW, the G3i system is GREAT!

I love mine.

:) CJ
 
wires

OK CJ I get what your saying,but what I'm saying is I fly a RV exp. airplane because I like to make things and experiment just like when I buit my on fi boost pump I ask that question 2 years ago and after no response from a member I ordered parts from Summit Racing and after trying a.couple different pumps got it right and I would be glad to share info.Now I thought it would save some time if someone who has done it before would share info.
Thanks to All
Bob
 
wires

Just to be clear I'm wanting to put plugs on slick wires.
That why I did not buy g3 I plans!
Bob
 
Ah!

I see now what you want!

Right, that is quite different.

I was set on the result, not the method.

Maybe all my confusion will bring this thread to someone's attention that can help you with your quest.

:eek: CJ
 
you should be able to find the plug ends and crimper on-line. Custom wire sets are sold with the ends un-attached. The connector and boot come with the set, but I am sure you can buy them somewhere. Pretty simple to do. If your lines are shielded, you'll need to strip it back and be sure it doesn't contact the connector.

Be sure that you get non-resistor plugs to use with the mag.

Larry
 
Thread drift, sort of...

Question about the recommendations against resistor auto plugs.

Aren't the stock a/c plugs resistor plugs? I can't ever remember checking the actual resistance of an resistor automotive plug in a car (it's been at least a decade since I had to change one), but I do know that a/c plugs are expected to have at least 1k-1.5k of resistance when new.

So what's the straight scoop?

Charlie
http://www.qaa.com/resource-center/tempest-tech-tips/tempest-tech-tips-the-right-way-to-check-spark-plug-resistors
 
And sorta back on topic...

I wonder if one reason you see automotive wire with automotive plugs is the noise issue. IIRC, a/c plug wires are solid core. Solid core wires radiate a lot of RF energy, hence the shielding. Automotive carbon core or spiral wound plug wires don't radiate (at least not like solid core wire) so the shield isn't needed. Think about the electrical havoc that would be wrought in a car, if there wasn't *some* kind of magic in the plug wires; there's a lot more energy in them than in a/c magneto wires.

Point is, you might need those metal shielding cans if you retain the stock wires when using auto plugs.

Charlie
 
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plugs

Back to post #9 that says don't use resistive plugs.on mags can that be backed up with stats.
Bob
 
lr172 said:
you should be able to find the plug ends and crimper on-line. Custom wire sets are sold with the ends un-attached. The connector and boot come with the set, but I am sure you can buy them somewhere. Pretty simple to do. If your lines are shielded, you'll need to strip it back and be sure it doesn't contact the connector.

Be sure that you get non-resistor plugs to use with the mag.

Larry
Click to expand...

Aircraft spark plugs are resistive.....
 
mags

I believe slick mags and to a lesser extent CMI S-20 series mags will run quite hot if solid core wires and non-resistor plugs are used. Standard aircraft plugs are 2K-5K ohms. This is to limit current flow in the ignition circuit but specifically in the magneto's coil. You would be risking an early heat related failure. CMI 1200 series mags are a different animal, their coils are much larger and can take the heat from the increased current flow. Back before the electronic ignition took over, many performance focused folks ran 1200 series mags, solid core wires, champion plugs with large gaps, converted to non-resistor by removing the resistor element & replacing it with a piece of brass rod. BTW this eliminates the failure point (the removable resistor) of champion plugs. Good Luck, Russ
 
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rv7charlie said:
Question about the recommendations against resistor auto plugs.

Aren't the stock a/c plugs resistor plugs? I can't ever remember checking the actual resistance of an resistor automotive plug in a car (it's been at least a decade since I had to change one), but I do know that a/c plugs are expected to have at least 1k-1.5k of resistance when new.

So what's the straight scoop?

Charlie
http://www.qaa.com/resource-center/tempest-tech-tips/tempest-tech-tips-the-right-way-to-check-spark-plug-resistors
Click to expand...

Auto "R" plugs have a typical 5K resistance and aviation plugs are 1K. Auto ingitions have plenty of power to spare and easily pass the resistance. This approach keeps noise down. Mag's have much less energy and you'll lose too much energy with R plugs. There is a design factor here as well.

EDIT: I should add my inexperience here. I don't know the resistance of a non-R auto plug and the previous poster is correct that you need to match the resistance of the plug to the coil design. But I do know that the designed resistance of a standard plug used with the common slick and Bendix mags is 1K. You can do some research here. I am sure some of the plugs have different resistance valuse to match different mag designs.

As I think more about this, look at what the G3i system uses. They need a plug that will work for both a modern ignition AND a standard mag. Maybe the R plug will provide acceptable results. However, even if it does I doubt it is optimum. In their case it is a backup only and doesn't necessarily need to be optimum.

Larry
 
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AK4x4 said:
I believe slick mags and to a lesser extent CMI S-20 series mags will run quite hot if solid core wires and non-resistor plugs are used.
Click to expand...

The harness provided by Slick has a solid core. If you look inside the cap, you can see that they solder on the connector/button. On the flip side, you do not want to run modern ignition setups with solid core wires. This is why the G3I system replaces the whole wire and not just the plug termination.

Larry
 
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plugs

The comments about mags not having any where new the power as electronic ignition is not spot on as a mag at 2700 rpm has as much or more spark as EI.The resistance of the plug is to stop plug erosion and for the spark to jump a wider gap.Now the problem with mags is at low rpm it doesn't have much spark for starting that's where the impluse comes in to produce more spark at low rpm.
Bob
 
Capacitance...

rv7charlie said:
I wonder if one reason you see automotive wire with automotive plugs is the noise issue. IIRC, a/c plug wires are solid core. Solid core wires radiate a lot of RF energy, hence the shielding. Automotive carbon core or spiral wound plug wires don't radiate (at least not like solid core wire) so the shield isn't needed. Think about the electrical havoc that would be wrought in a car, if there wasn't *some* kind of magic in the plug wires; there's a lot more energy in them than in a/c magneto wires.

Point is, you might need those metal shielding cans if you retain the stock wires when using auto plugs.

Charlie
Click to expand...

Im no EE, but the outer conductive braid on aircraft wires is part of the ignition system, not there for shielding exactly it forms one element of what is essentially a coaxial capacitor with the other element being the center conductor, storing energy until the plug gap is overcome by voltage, then the electrical field collapsing thru the plug.
That's about the depth of my understanding of how it works, so I don't understand how you can safely remove it from the system and switch to auto wires, maybe someone can explain it to me.
Tim Andres
 
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6 Gun said:
The comments about mags not having any where new the power as electronic ignition is not spot on as a mag at 2700 rpm has as much or more spark as EI.The resistance of the plug is to stop plug erosion and for the spark to jump a wider gap.Now the problem with mags is at low rpm it doesn't have much spark for starting that's where the impluse comes in to produce more spark at low rpm.
Bob
Click to expand...

I said that they don't have as much power, not that they were inferior or wouldn't produce a spark. I was referring to voltage/current and how that inter plays with plug resistance. Open the gap to .035" like an auto system and see how well it performs. Mags are limited in their utility because they don't pack the same voltage/current punch that an electric coil does. There is a reason that people run better LOP on EFI and it has to do with a more powerful spark event. It is due to a longer and more powerful spark event afforded by th increased voltage and current as ell as the associated larger gaps allowed.
 
rv7charlie said:
I wonder if one reason you see automotive wire with automotive plugs is the noise issue. IIRC, a/c plug wires are solid core. Solid core wires radiate a lot of RF energy, hence the shielding. Automotive carbon core or spiral wound plug wires don't radiate (at least not like solid core wire) so the shield isn't needed. Think about the electrical havoc that would be wrought in a car, if there wasn't *some* kind of magic in the plug wires; there's a lot more energy in them than in a/c magneto wires.

Point is, you might need those metal shielding cans if you retain the stock wires when using auto plugs.

Charlie
Click to expand...

Charlie has a good point here and you should really do some research here before proceeding too far down this path. I didn't think of it when giving you thoughts on using the existing wires.

Larry
 
autoplugs

OK here.is the skinny on were I'm at with putting autoplugs on Slick wires I ordered Taylor boots and terminals from Summit Racing and plug adapters from Efi2 that had great customer service . So last weekend I went to plane and installed the boots. It worked out Tgreat by dissembing the Slick ends and saving parts so if I ever won't to reassemble I can. Then I used heat shrink to keep the braided wire back 3/4 " and doubled it.Next took .o32 safety wire and inserted it 1/2" in the end of slick wire and wrapped it around three times then crimped terminal and put boot on.Next installed the naval brass plug adapters and torqued to 30# and installed NGK BR8 plugs @ $2 each gaped at 25.Now it was time to put all 4 wires on impluse mag on top and the right mag to the autoplugs on bottom.Time to do a run up and a mag check and it checked out good and after flying it for 2 hrs and inflight mag checks its running great.
Bob
 
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