stevieturbo

wires were cracked or plugs ?

RealQuick

iTrader: (14)

wires.

pantera_efi

iTrader: (1)

Hi Quick, this make great sense, what brand of wire ?

I fit FireCore 50/250 wire, call Rick G.

I do NOT use the steel covers.

Lance

kingtal0n

iTrader: (1)

You mean stock truck plug wire steel covers? Any reason why to avoid them?

Dian

last time i had a missfire, i was logging lean spikes of 0.9 lambda, up from 0.78 or so. so this was a very light missfire?

stevieturbo

It could be many things, misfire, dodgy sensor, valve related issue etc.

I'd imagine the stock wires with the metal shroud...used in close proximity to a turbo manifold, would cook the wire, not protect it.

RealQuick

iTrader: (14)

Lance, I was using Taylor 10.4mm Wires. I had used MSD's previously, ACCEl 9000, stock ones...

RealQuick

iTrader: (14)

There may not have been misfires... or very light ones. Previously, I had a bad stutter under load with burnt wires (two separate occasions). I did not feel it this time around... and only noticed the burnt wires when removing them to change the plugs. They may not have impacted my numbers. I just figured I would report the observation.

I still think the main culprit is the clutch loading/unloading the motor/turbo.

RealQuick

iTrader: (14)

I am not using metal shrouds, just the DEI heat sleeves. What kills my wire is they need to make a tight u shaped bend to fit thru the primary tubes and go up to the coils. The heat combined with the tight bend just appears to be too much for the different wires I have tried.

stevieturbo

Can you wrap those header tubes where they are in close proximity to the wires ?

Even heat sleeving...can end up cooking the wires. Allowing air to circulate is often the best way of keeping things cool, as a lot of the damage is caused after shutdown when everything just bakes and the heat sleeves can just keep heat in.

RealQuick

iTrader: (14)

Manifolds are ceramic coated, wrapped with DEI lava wrap and wires were sleeved. I needed the sleeves to keep the wires off the manifold. The new wires will have a nice 90 degree bend, so no more bent wires and potentially no heat sleeves.

stevieturbo

Ahh right.

I guess keep some stock of wires and just replace them often then.

I have used the Firecore wires myself, with their Promod boot and they were a nice fit and good quality.

When I changed to IGN coils though I just bought some cheap wires to cut/shut to suit what lengths I needed. Think they were Ford Explorer wires or something, the boot was pretty much identical to Firecores Promod boot which I liked.

kingtal0n

iTrader: (1)

I put some thought together based on what little physics i understand, it is not directed at this thread it is just a general sense of insulation vs energy transfer

I would equate the sleeve to the metal shield. both are designated as insulators, they would do the same thing i would think. so i guess if you are going to use a sleeve, you should use the metal shield to add to the insulating effect. If the temp of the wire is less than the temp of the surroundings, then the insulation is working. The temp of the wire unshielded would rise because of the rate of energy transfer from the air to the wire. the max temp is set by the ambient air. If the ambient air raises to 200*F, then the max temp of the wire is near 200*F. If the wire starts off at 100*F, it raises to 200* at some rate, which depends on how well insulted or not the wire is from the ambient air or anything touching the wire.

As to the temp of objects during a shutdown, the higher the temp the wire is at during a shut down (which will not exceed the temp of the surroundings, there is no temperature increase upon a shut down) the longer it takes to return to baseline temp. If the temp of the engine or nearby air is dropping it will allow the wire to cool as well, and the rate the wire cools is directly related to it's insulation. If both the wire and the ambient (near air to the wire when i say ambient) are at the same temp, or nearly, the rate of temp drop in the wire will be slower than the same wire without insulation. Two factors work against this theory which make it unlikely as a real solution to the 'cooking problem'. The first is higher-than-acceptable ambient temp possible of the air near the wire. Temp near wires may exceed 200*F and may approach 1800*F depending on location and engine application. In some instances the wire could never be allowed to approach such a high temp, and in that application heavy insulation is necessary and preferred to having over/exceeded-temperature wires. In other words, with such a high nearby temp, any wire which starts low and ends at a high temp is going to overcook without the slowing effect of insulation, and ultimate reduction in final wire temperature it provides if any. The more insulation is available to the wire the lower the final temp of the wire will be when checked later as higher temperatures and duration are applied. It may reach a steady state or not, with temps possibly approaching the full temperature or not, depending on the application. This means any possibility of heating wires beyond a reliable temperature automatically require insulation. The second factor that works against the theory that insulation slowing the rate of temp reduction as an argument against insulation of wires in a cooling engine is the time that a given engine would be expected to perform at max temp output. In other words, marine engines or track engines that get a non-stop demand for output may reach higher plug wire ambient temperature conditions and are more likely to develop the max steady state given a specific duration of use at high output. If the air around a marine engine (lets say it is enclosed) reaches, say 1500*F then if this temperature is too high for the spark plug wire, this will require insulation. Even if the engine is to be vented and cooled quickly, and the fact is that the wire would cool faster without insulation, there still stands the initial demand for the insulation to protect the wire from the total high temp that exists when the engine is running. IF, on the other hand, you are able to remove the insulation after you shut down the engine, as long as the nearby temp of the air decreases dramatically (within a specific rate /time period) you would theoretically speed the cooling of the wires (but who would do that), and in a second case, if you could somehow guarantee the entire steady state or high output operation would maintain a low enough temperature that would not affect the wire adversely it would similarly be ok to leave off the insulation. It could be said the the construction of all wires seems somewhat adversely affected by the high temperature an engine might possibly make and the majority of application (I think turbo, a majority) call for insulation to prevent the highest temp from reaching the plug wires regardless of their stated manufacturer tolerance allowments and is a good idea.

In short I will be running the metal shields and plug wire insulators, and I may even take the insulating step even farther in some respects. If there is a technical reason why the metal shields are non desirable (maybe they cause wires to break easier or something I have not discovered yet) I would love to know. The mere fact they are made of metal vs cloth material makes no difference from the insulation point of view or 'cooking', I think maybe the metal frying pan aspect is bringing to mind the idea of a cooking egg. Of course the coefficient of the rate of change or exchange of temperatures is different in metal vs cloth (most likely) and I might even suspect the cloth was more effective at "cooking" than the metal (but that is just a hunch) as we are looking to cooking like " an oven" or a place where temp can be insulated and warmed. keep in mind the temp rise is not coming from within the wire as in an oven. Any cooking action is due to temp which persisted through the insulation.

pantera_efi

iTrader: (1)

Hi King, good "tech" again.
You ASKED "metal" shields, are they good ?

I do not use them thus NO experience.

I DO TEST SPW by the use of my CO-2 Test bench (eight channel).
This is one method that allows a different Pico Load (1.5uF) with a simple change of CO-2 Pressure.
The chamber allows for Spark Plug, Boot, Wire and Coil testing.

The FIRST thing I show my viewers is the "corona" effect by turning OFF the room lights.
ALL ARE SURPRISED at the light emitted by the wires, the Corona.

The next test is to fit a 10.4 vs 8.5 wire.
The 8.5 has less Corona.
WHAT ???
The reason is that when the wire is extruded there is a greater change for small air pockets to form with the thicker insulation.
The NEXT test is for "flashover" using an INCORRECT boot, one that is too short to cover the plug insulator.
I "heat" the air around the plug, as it becomes hotter flash over takes place.

Lance

kingtal0n

iTrader: (1)

This is very technical info. You are much higher up in the tech world than most hobbyist. Personally, having no equipment, I am very limited in how I test my engine setup, as are many home-garage enthusiasts. We appreciate what you share. As far as testing spark system without special equipment, my caveman method is to 'strain' the system, by initially providing the harshest environment possible. For example, with my first 5.3l engine, I used the most mundane setup possible: high mileage used oem truck wires, new but ungapped (0.045"?) plugs, rusty/aged truck coils, no heat shields or insulation, everything is exposed to high temp. This way I might expose the 'weakest links' in the ignition before upgrading all components. Using this method I have found 2 cylinders which misfire as temperatures rise, especially near idle. Once I replace the offending coil/wire or determine that the location was specifically too hot, I can be sure that the system overall has been removed of its weakest links and all cylinders will no longer misfire under these harsh conditions. THEN I go back and use new wires, excess insulation, gap the plugs down, and assured the coils and wiring are good for the moment (its more likely than if I skipped the stress test). In other words, initially installing high quality components might mask a weak coil or a weak area in the installation (a high temp area that needs special attention, like extra insulation) as initially the high quality components and small gap would help keep the ignition system from misfiring, masking one or two cylinders which are on the verge or deteriorating more rapidly than the others, which is something that should be fixed before attempting to rely on the setup for thousands of miles.

pantera_efi

iTrader: (1)

Hi King, thanks.

One method I have used at the track was to "power brake", my helper's foot,
with my observation of the "underhood" area looking for light from the wires. (arcing, corona, sparking)

Lance

RealQuick

iTrader: (14)

Quick update:

installed new plug wires, used two DEI heat sleeves on the wires, and replaced the plugs with NGK Iridium projected tip 8 heat ranges plugs gaped at 0.025". Went out for a quick spin at 9-10psi, car pulls great in 2nd gear. Some observations:

1) speed vs time is smooth now (does not fluctuate)
2) MAF curve is silky smooth now (does not fluctuate)
3) A/F is about 1.5 points leaner now.

kingtal0n

iTrader: (1)

Yeah, bet you are pretty happy right about now. Congrats on the new engine. (crosses fingers, 80% of LStech will read between the lines)

RealQuick

iTrader: (14)

Yeah, pretty happy

I am a little confused about being leaner now though.

kingtal0n

iTrader: (1)

It is, right? I am always surprised by the changes at the gauge when it comes to spark quality. Makes you really wonder how the gauge thinks, and if there are better gauges out there. Of course there are. The one we buy for $150 and stick in the panel of our car is just a little reassurance, a little extra chocolate. It goes along with the rest of the meal, you have to taste everything and decide for yourself. Sometimes the ingredients are hidden, and we are not chefs, just tinkering around with our pathetic gauges.