Spark plugs?

[bandkiller]

Any body know anything about converting aircraft plugs and wires over to automotive plugs and wires? I was told a J616 plug will fit and then you swap your wires out to 8mm wires and your done, any info on finding those plugs and what they go to would be great, or is it not possible.

 

[Doc Holliday]

I don't know what engine you have, but by the gist of your question I'll assume it's an aircraft engine.

I run a Continental PE-150 (220 GPU). For this engine, I'd recommend Autolite 386 plugs gapped at .018 and Moroso 8-mm Blue Max solid core ignition cable. You'll have to work to fit the 8-mm cables thru the mag cap, but I think the extra diameter is worth it. Use silver solder to make the balls on the inside of the mag cap.

We've also used Champion D16s and D21s (hot plugs). I guess it depends on what you perceive to be best.

 

[bandkiller]

I have a 4 cyl continental, I was told it's a 0-200 or a pe-90 not sure. They make an automotive plug as big as an aircraft plug? Sorry I am new to the airboat and aircraft engine world. I was told mine takes a J616 but the auto stores don't have anything on that number. Any more help would be great thanks.

 

[cowboy]

Get the D-16 Champions, or the autolites, like the doc said.
The gap he quoted is very important, so make sure you go with an .018" gap. That's where I'd start. All engines are a little different, so run the 16's for a while, and then read them for color. If they look white, or grey on the insulator tip, the cool it down some. Champions are cooler, the lower the number. If they wan't to foul out, then step up from a 16 to a D-18, and try that. You want to run the coolest plug you can that won't foul under extended periods of idle, or low speed operation. At least on aircraft style engines.

Most folks run 7mm solid core / non suppression ignition wires.
It's a little tough to find them in that style.

8mm is nicer to have, and can be used, but Like the Doc said, it's a little tougher to interface with the mag wire cap plates than 7mm.

Suppression type wire "resistor" will work just fine, cause that's probably whats on there right now. If you buy some, just make sure it's got a solid core, not arimid fiber.

Before you realy get started in converting the wires to automotive style, take the wire cap off of the mag, and look in there. You'll see how the plug wires terminate in the mag, and what your up against there.

I've never done the silver solder ball meathod, but it's not a bad idea.
Some people thread a small brass wood screw directly into the wire core, to make the contact terminal in the mag, for each wire.

Some people will take the ferrule from a 1/8" pop rivet, and crimp it on the wires core for this purpose. Copper ones work well if you can find them. Aluminum is the next best choice.

You could pm Mike Thurman from this site. He can make a new ignition harness for you, and you can bolt it right on.

I hate making ignition harnesses. Time you figure the cost of running down the right cable, ends, and all your time farting around with making it all work, his harnesses are really a bargain. If your engine is a single mag motor, then it will be even cheaper, cause you'll only be buying one harness.

 

[Buck Thruster]

Good post Cowboy.

The C86 or C87 AC spark plugs are also a good choice to replace the aircraft spark plugs on most aircraft engines.

Paying to have someone who knows what needs to be done is money well spent in my opinion.

 

[Anonymous]

Champions have a plating on them. Autolites are just blued.

 

[Skeeter]

I like NGK WR-5 plugs the best. Ive tried them all. And run Moroso High Temp 8mm wires. On my 520 :twisted:

 

[rbjscott]

Lead solder works also and is easer to use--lower temp. I have not seen a soldering iron that will melt silver solder.

 

[Anonymous]

Some people will take the ferrule from a 1/8" pop rivet, and crimp it on the wires core for this purpose. Copper ones work well if you can find them. Aluminum is the next best choice.

Or you could just go to NAPA and get some brass distibutor clips, part number 727008. They work with 7mm wire

 

[bandkiller]

Are all of these plugs listed above available at just an automotive store or are these special order plugs? Thanks again for all the help

 

[rbjscott]

A good autoparts will have them. An autoparts that leans toward the industrial market is a better bet. The plugs listed are industrial plugs--natural gass engine etc. There was a person advertizing to make make mag. ignition harnesses at what I thought was a fair price. I lost his information.

 

[cowboy]

You can get the plugs at Napa, ar any real auto parts store.

The terminal ends that Red showed us above, probably wont work in most magnetos. If the magneto end is not terminated properly, you stand a good chance of the spark tracking to groung at the mag dist block. Once the blocks got a good carbon track on it, it's gonna be junk. The terminal wells in the mag are not very deep, and then you've got a grounded plate right above them. The terminal end has got to be right on the eng of the wire. They won't tolerate the terminals that crimp back up on the wire jacket. If it does work, it wont for long. I'm not trying to say Ha- Ha-, your wrong Red, cause I wish it was that easy to use those style ends at the mag.

Reds right about the champions having a plating on the base of the plug. The AC's don't. The non plated ones will rust allot sooner than the champions. I've seen people I respect running the NGK's, and the plating on those looks real nice. Denso makes a good plug also.

All of the plugs mentioned above will run just fine. Don't forget the .018 gap.

If you buy a pre-built harness from Mike Thurman, your troubles will be over. Like I said, if you figure in your time to chase the items down, then buy them, then fart with putting it together..... It's a real bargain.

At least when I figure how valuable my time is to me. You can P.M. Him on this site. Here's a link to a wire set he's selling on ebay. It has a good picture of how the terminals should look at the mag end.

I don't have his number handy. Somebody can jump in here with his number. Just call him, and tell him the model number of the mag, and what type engine you have. It should be pretty cheap for a 4cyl single mag wire set.

I recently got a set from him. They worked, and fit very well. It was worth every penny, and I am capable of making my own harness. I just hate farting around with plug wires. It's just an aggravation, but your engine aint gonna run worth a crap without good plug wires on it.

http://cgi.ebay.com/ebaymotors/Bend...ewItemQQcategoryZ26437QQitemZ4613123086QQrdZ1

 

[Doc Holliday]

$90.00 looks like a VERY fair deal. I paid $65 for the Blue MAX 8-mm wires, and spent at least two hours measuring and soldering them into the cap.

Silver solder does require a hot soldering iron. I believe the one I used was set to 680F. Helps to work for a computer manufacturer. Me and my bud actually had fun making the balls needed for the tips.

While I was proud of the work I did myself, I'd probably spend the extra $25 to let someone do it professionally.