spark plug caps

[Fireball]

could anyone tell me the reason for resistance in a spark plug cap? I've just finished making my HT set and lo and behold I've come across caps with resistance in them. I'm just about to connect my battery to the wiring loom I've dreamed up, then hopefully, if everything doesn't melt, I'll see if the engine will actually fire up......
Thanks in anticipation,

James

[Fireball]

as an addendum to this, I'm using copper HT leads and Champion RF9YC plugs. Hopefully the radio interference won't annoy outside of a 10 mile radius..

[Roger King]

Just be careful according to your ignition system. A lot of the US systems require spiral wound carbon core, but I have no idea what your setup is!

[Paul Blore]

The MSD systems certainly need the spiral wound carbon core leads.
I think some of the old style screw on plug caps had suppressors in them, which probably accounts for the resistance. The modern ones tend to be a direct connection to the plug using a metal crimp connector onto the end of the cable.

Paul

[amulheirn]

Hi James-

I spent quite a bit of time looking into the right plug for my engine, and if I remember rightly, the 'R' in a Champion spark plug part means it has a built-in resistor for RF suppression.

http://www.championsparkplugs.com/find-my-part
http://www.gsparkplug.com/shop/media/im ... ampion.pdf

So I'm guessing if there's a resistor in the HT leads as well that could cause an issue? Weak spark or something maybe?

Cheers,

Andrew

[Fireball]

gents,
I'm using a lumenition ignition system and there's no resistor in the caps as I've made these up manually.
Roger, I don't think my car will ever make it over the pond although it is destined for Europe one day..
I hadn't contemplated compatibility with the ignition system, isn't the lumenition just a trigger for the coil?

James

[Roger King]

gents,
I'm using a lumenition ignition system and there's no resistor in the caps as I've made these up manually.
Roger, I don't think my car will ever make it over the pond although it is destined for Europe one day..
I hadn't contemplated compatibility with the ignition system, isn't the lumenition just a trigger for the coil?

James

Hadn't realised you were overseas! I don't honestly know, I haven't had a Lumenition system since my old Triumph Stag days... which ran copper wires.
It's generally the US systems that require spiral bound. I presume you have a Rover motor as I don't think Lumenition do kits for yanks.

edit - I'm getting my wires crossed here. I don't think Bishop Auckland is abroad, unless it's a religious suburb in NZ... my point was that cars over here with US engines (i.e. Ford) have US ignition systems, of which the modern varieties prefer spiral wound cable.

As you were.

[Fireball]

Ha! (I'm getting my wires crossed here) Was the pun deliberate? You're right, I'm based north of England and I started the confusion when I thought you implied I'd be taking the car over to the US!!
I'm running a ford 260 with a lumenition system and a stock dizzy.
Could anyone have a guess at what sort of power I'll get from a stock 260 with cast iron heads, cam and a 4 x holley? I understand these engines don't mod easily and don't give out much power

[Roger King]

Ha! (I'm getting my wires crossed here) Was the pun deliberate? You're right, I'm based north of England and I started the confusion when I thought you implied I'd be taking the car over to the US!!
I'm running a ford 260 with a lumenition system and a stock dizzy.
Could anyone have a guess at what sort of power I'll get from a stock 260 with cast iron heads, cam and a 4 x holley? I understand these engines don't mod easily and don't give out much power

Wow - you must be on the originality kick too! The only other 289 I have heard of with a 5-bolt block... you must be running a toploader, too? Or have you used an adapter to take a T5? At a guess, if toploader, is your entire drivetrain from a Sunbeam Tiger? All MkI Tigers used the 260. Your spec would be pretty close to a Tiger's as well, but difficult to guess at power output. The stock Tiger used an Autolite carb (I think), and was quoted at something like 160 brake, if memory serves. Doesn't mean much, but I imagine the torque figures would be pretty good. The stock Tiger pulled a 2.88 diff ratio!
Didn't know you could get Lumenitions for US Ford distributors, most go with Pertronix. I'm sure you can mod a 260 - it's the same block as a 5-bolt 289, and mine's been discreetly modified quite extensively. It's just that folk don't bother, as they can bolt a 302 in and modify that instead.

[Fireball]

Hi Roger,
yes it is a toploader although where the running gear came from I don't know as I bought the car already built; I know the block is 1962. The ignition system is the standard optronic lumenition:
http://www.lumenition.com/new/main.php/optron/

In hindsight it may have been easier to start from scratch but I thought it just needed a little tlc and it would be back on the road again.. Three years later and counting.