wire resistance
so 4 inches approx 100 mm so 21 x 3-400 so that wire resistance sounds about right eh?
so 4 inches approx 100 mm so 21 x 3-400 so that wire resistance sounds about right eh?
Spark arc (1 Viewer)
- Thread starter IDave
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- Thread starter
- #62
Yeah, I think so.
Maybe what I have is really a diesel engine, and these are just glow plugs.
Talking of diesels, I think I'll retreat back to "diesel section" where I can lie low for a while.
I've done enough damage here.
Hell. I've been lying awake thinking about your problem and I'm even starting to suspect that there's something wrong with the air you have around there.
I'm stumped!
I've done enough damage here.
Hell. I've been lying awake thinking about your problem and I'm even starting to suspect that there's something wrong with the air you have around there.
I'm stumped!
- Thread starter
- #64
I've been thinking, what's left that's in common with all 6 plugs and wires that I haven't switched out?
Ignition wire to coil, secondary wire coil to distributor, distributor itself, condensor, engine block...
Do you have a ground wire going from the block to the frame?
- Thread starter
- #66
Yes, I do. And its old and oily, so last night I ohmed between the block and the frame, came up with 0.6 ohms. Ran a jumper cable between the block and frame just to be sure, but it made no difference. Maybe I should jumper the block directly back to the negative battery terminal?
Well I implied I was going to stop thinking about your problem IDave but that's easier said than done.
Have a read of this:
Arcing Plugs - FSC Forum
At least it shows that the demons haven't singled you out entirely on your own for this problem.
The last post is interesting as it suggests a lean mixture may have such a "spark killing" effect that the spark chooses to go outside. ..... But I don't know if there is any truth in that.
PS. I do know that a plug can spark in fresh air yet fail to spark when fitted inside an engine (where it gets fueled air). - But I thought that was always associated with having "a weak spark" in the first place.
PPS. Please find the solution soon. ..... For my sake as well as yours
Have a read of this:
Arcing Plugs - FSC Forum
At least it shows that the demons haven't singled you out entirely on your own for this problem.
The last post is interesting as it suggests a lean mixture may have such a "spark killing" effect that the spark chooses to go outside. ..... But I don't know if there is any truth in that.
PS. I do know that a plug can spark in fresh air yet fail to spark when fitted inside an engine (where it gets fueled air). - But I thought that was always associated with having "a weak spark" in the first place.
PPS. Please find the solution soon. ..... For my sake as well as yours
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- Thread starter
- #68
My local mechanic mentioned the lean mixture (as well as high compression) theories.
I figure since it happens with the hand choked pulled (or not!) and with the plugs fresh, or a little blackened after warming up choked, that I'm not running a lean condition to cause it!
As for high compression, well, it's a 45 year old F135 tractor engine....
No, I know I'm not the first to experience this. Doesn't sound like the guy in your link came up with a solution...
corona
Corona Effect : Corona Effect is a phenomenon which may be observed when viewing an engine running at night with the hood up. This phenomenon appears as a greenish blue halo around the wires. The amount of corona is dependent mainly on the humidity of the air and the amount of voltage pushing the electrons through the conductor. As the voltage and/or humidity increase, a more pronounced corona is observed. Be aware that it does not cause any problems. It is normal and there is absolutely nothing wrong with the wires. An actual arcing of a spark to ground does indicate a problem. A spark going to ground will make a noise, corona does not make noise.
Vitek Performance - Auto Accessories
is it in fact corona? if so is it really worth worrying about--- or is it snapping spark
Corona Effect : Corona Effect is a phenomenon which may be observed when viewing an engine running at night with the hood up. This phenomenon appears as a greenish blue halo around the wires. The amount of corona is dependent mainly on the humidity of the air and the amount of voltage pushing the electrons through the conductor. As the voltage and/or humidity increase, a more pronounced corona is observed. Be aware that it does not cause any problems. It is normal and there is absolutely nothing wrong with the wires. An actual arcing of a spark to ground does indicate a problem. A spark going to ground will make a noise, corona does not make noise.
Vitek Performance - Auto Accessories
is it in fact corona? if so is it really worth worrying about--- or is it snapping spark
I would use a set of jumper cables and run to frame, battery, and block (although it sounds like you've tried block already). It makes sense to rule it out, and it is common to every plug. I would imagine you would notice poor perfomance but again; it would be good to rule out negative resistance as a culprit.
I'm eliminating the "corona theory" because I've never seen it in action on a motor vehicle (although I love watching the "mercury-arc rectifiers" at Ferrymead and MOTAT here in New Zealand - and maybe coronas look similar
) and IDave was actually drawn to the problem by the NOISE of the "electrical discharges".(And I'm used to looking under the bonnets/hoods of petrol-engined vehicles at night as a means of finding "high tension lead faults".)
And I don't understand the suspicions directed at "earthing of the block/head" or at "distributor/leads" because it seems to me that they are doing their jobs admirably well. (After all, IDAVE doesn't get a WEAK spark!)
Brainstorming for causes that could cause this, I come up with:
- IDave has fitted plastic/insulating caps to each plug (under the lead-caps) that is causing the sparks to travel outside the porcelain, or
- He has used an extraordinarily-effective dielectic grease as antiseize when threading the plugs into his head, or
- The head has ceramic/insulating thread inserts for each plug
Solution? - Maybe downgrade to the weakest-output coil you can find IDave? (Get one off a Lada perhaps.)
- Thread starter
- #72
Definitely invisible in daylight, as would expect from corona.
The only snapping sounds I've heard have lasted less than 20 seconds on 2 occasions while I'm driving in the dark, so I couldn't say if that's what it was coming from. I can hear ticking while the engine is running, hood up, but I think it's just valve noise. Couldn't swear to it, tho!
The plug wires definitely do not glow in the dark.
The color of the phenomenon is white to whitish yellow, not blue or other color.
That site says corona on wires is harmless, but doesn't address corona between boots and base of plugs.
- Thread starter
- #73
Definitely going to do this, and clean up all of my ground strap and neg battery terminal connections.
- Thread starter
- #74
I'm eliminating the "corona theory" because I've never seen it in action on a motor vehicle (although I love watching the "mercury-arc rectifiers" at Ferrymead and MOTAT here in New Zealand - and maybe coronas look similar
(And I'm used to looking under the bonnets/hoods of petrol-engined vehicles at night as a means of finding "high tension lead faults".)
And I don't understand the suspicions directed at "earthing of the block/head" or at "distributor/leads" because it seems to me that they are doing their jobs admirably well. (After all, IDAVE doesn't get a WEAK spark!)
Brainstorming for causes that could cause this, I come up with:
But of course all of these are ridiculous.
- IDave has fitted plastic/insulating caps to each plug (under the lead-caps) that is causing the sparks to travel outside the porcelain, or
- He has used an extraordinarily-effective dielectic grease as antiseize when threading the plugs into his head, or
- The head has ceramic/insulating thread inserts for each plug
Solution? - Maybe downgrade to the weakest-output coil you can find IDave? (Get one off a Lada perhaps.)
It is true that I was drawn by the noise, and if it hadn't happened I'd never have seen it, because I'd never have looked in the pitch dark. The thing is, it happens independent of the snapping sound. It's very conceivable at this point that it's been happening since the day I got the truck, and before, and the snapping was unrelated to the glowing, pulsing sparkplug phenomenon.
I have a very old coil that was on one or the other of my trucks that I could actually try...
Well that gives me an idea
Tonight - Reach in and try touching your coronas.
If they don't zap they're real coronas.
If they zap you then they're just your traditional common-garden-variety sparks/arcs.
PS. Make sure your pacemaker is working properly first though.
- Thread starter
- #76
How about if I wrap a thin wire around the exposed waist of the plug insulator and touch the other end to the cat and see what happens?
safety first
the cat? ahhhh yes, safety is job one Dave
you could touch a screwdriver to the block and slowly circle it around the wire and see if it jumps to the screwdriver
I am sure the cat would appreciate it
on the resistance of the engine ---the idea was that if the resistance of the threads to the block was a higher resistance to jump to than along the insulator to the block it might cause a prob so thats why I asked you to shoot that
As for the engine to ground ---well it has to jump to ground and if the resistance of the block to ground is high it would in fact be high for both the plug and along the insulator but it might be slightly easier along the insulator because of compression--Oh well, it was not hard or expensive to check so what the heck?
the cat? ahhhh yes, safety is job one Dave
you could touch a screwdriver to the block and slowly circle it around the wire and see if it jumps to the screwdriverI am sure the cat would appreciate it
on the resistance of the engine ---the idea was that if the resistance of the threads to the block was a higher resistance to jump to than along the insulator to the block it might cause a prob so thats why I asked you to shoot that
As for the engine to ground ---well it has to jump to ground and if the resistance of the block to ground is high it would in fact be high for both the plug and along the insulator but it might be slightly easier along the insulator because of compression--Oh well, it was not hard or expensive to check so what the heck?
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- Thread starter
- #78
How about grounding one end of a wire to the negative terminal of the battery and waving the other end close to a plug insulator and seeing if I get a snap and a spark?
I'm with Mr. Smith on looking into Magnecor wires or comparable quality.
But before you take that expensive step, IDave, do you have any Cruiser aquaintanences that you can borrow a different brand ignition wire from? All you need is one different brand wire to check for a difference from your engines wires.
But before you take that expensive step, IDave, do you have any Cruiser aquaintanences that you can borrow a different brand ignition wire from? All you need is one different brand wire to check for a difference from your engines wires.
- Thread starter
- #80
I'm pretty sure I have the wires it came to me with, which I think are Bosches. I'll have to go dig.
