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On the last outing we had some misfiring from arcing ignition wires. The car still has the original wire set so after 26 years and 65k miles, its time for a new set obviously.
The car has stock exhaust manifolds and no future plans for headers so we will opt for stock replacement type 7mm wire set. I ordered two sets which I will compare before deciding which to use. I’ll compare visible overall construction quality and do resistance tests and comparison. Is there anything else you think I should compare while I have the two sets on the bench?
Here are the two sets I’m comparing. Although both these links are from Advance Auto, I ordered the ACdelco set from Amazon for $80. The Carquest set had a coupon deal and the cost was $60.
You didn't mention the year or engine, but that may not be too important at the moment. From the pictures it looks like everything is already assembled on your wire sets.
I replaced mine the other year with the Delco set and as long as you replace each plug with the correct replacement you should be fine.
Something I did which made the job a little easier: I attached a length of twine to a wire and pulled it out leaving the twine behind to show the original wire routing. I then compared the original wire to the replacements to insure I picked the right one. To reinsert the new wire, I attached the twine to the end of the new wire and worked it back through the mess and put them back in the original routing. There's a couple of them that should cross to prevent misfire (from what I remember) and if they go back the way they came out it should not be a problem.
My 2 cents. Good luck.
I looked the two sets over. Carquest Premium vs. ACDelco. I took a few pictures below that don't say too much themselves but there they are.
Some observations;
1. Both sets came with 10 wires total which included 2 different coil wires in each. This is obviously to accommodate the post on the two different coils that can come on these cars.
2. Both wire sets have various length wires as you would expect and the lengths between the two sets are almost identical.
3. The outer insulation sheathing felt different between the two with ACDelco feeling spongy and slightly more flexible compared to a more rigid and less spongy feel to the Carquest Premium.
4. While both sets are listed as 7mm, the Carquest Premium are ever so slightly narrower. Micrometer measurement was 6.8mm ACDelco and 6.7mm Carquest Premium.
5. Looking down into the boots for the spark plug ends, the Carquest Premium set appeared to have slightly smaller connector rings. I used a spare spark plug to snap into each set. The result was, Carquest Premium took a bit more effort to snap in and definitely more effort to pull off. They snapped in with a prominent "click" compared to the ACDelco which had a looser feeling at connection.
6. I did resistance testing on each set. BTW, I also have a new set of Taylor Spiral Wound 8mm that are for another non vette LT1 car we have. So in addition to comparing resistance between Carquest Premium and ACDelco, I also tested a Taylor wire to add to the comparison. I tested the longest and shortest wire on each set. On the Taylor, I only tested one equal length shorter wire just for comparison since they are commonly in use on our cars. Here are the resistance test results.
No matter what you choose stay with gray or black. Color wires on a stock engine look totally out of place. And anyway with a stock ignition system stock wires are more than enough. Same with the distributor cap.
No matter what you choose stay with gray or black. Color wires on a stock engine look totally out of place. And anyway with a stock ignition system stock wires are more than enough. Same with the distributor cap.
I have no concern about color really as the stock routing of LT1 wires is so buried you can hardly see them. But I wasn't planning to use the red Taylor wires on this car if that's what you mean.
Well, then go with red wires. If the car has a stock looking engine go with what was stock. This is the best receipe to keep a car resale value. To each their own and taste can't be debated but this is how I see it.
I saw it suggested to remove the wires as an assembly and still in the looms. I’m glad I saw this method and it turned out not too difficult to remove each side. I’ll swap the new wires into the looms and transfer the protectors over while on the work bench.
The passenger side was without the need to move anything out of the was and the entire process on that side was done from above.
On the drivers side I unbolted the ASR motor and leaned it back out of the way. I also removed the splash guard by the shock mount. I reached up from underneath and popped the wires off the opti then pulled them past the accessory bracket one at a time from above.
I got the Carquest Premium wires assembled into the looms and installed them today. On the install I had to move one more part out of the way. It was the belt tensioner which was easier than I thought to remove and install. The problem was on the drivers side with snapping the boots back on to the opti. I was able to feed the wires down towards the opti from above. Then from underneath I could reach up and get them started onto the opti but I could not get enough pushing power to snap them fully on from underneath. That's where moving the belt tensioner became necessary. After it was out of the way it was easy to snap the wires fully on to the opti.
absolutely 100percent, why gamble with auto parts store brand when the originals lasted this long. ive been a technician since 1985, i always use OEM parts when i can.
absolutely 100percent, why gamble with auto parts store brand when the originals lasted this long. ive been a technician since 1985, i always use OEM parts when i can.
Being a technician since 1985, can you assure me that the replacement parts that are made today always the same quality as the original ones that were made 28 years ago? With an older car, even if you buy something labeled as OEM replacement, are you not still taking a gamble?
Carquest makes more than one grade of ignition wire and the ones I got are the Premium. Nothing about their construction looked or felt sub par compared to the AC Delco. Furthermore, the Carquest set measured at about 50% of the resistance that the AC had. The lower resistance won me over to Carquest Premium.
You know, I got curious about the previous resistance measurements I took by comparing the new Delco set with the Carquest Premium set. You can look at my numbers in the previous post in this thread and see that the new Delco wires have double the resistance when compared to the Carquest Premium.
Anyway, I decided to check the resistance of my original AC Delco wires with 27 years and 65k miles on them. I was surprised to find they have pretty low resistances. Here’s a comparison
The longest original Delco wire. 1699 ohms
The longest new Delco wire. 9900 ohms
The shortest original Delco wire. 1051 ohms
The shortest new Delco wire. 5900 ohms.
Question; Do ignition wires lose resistance with age and use? If anything I would assume they might gain instead of lose.
If they typically do not lose resistance over time, I’m concluding that the new AC Delco wire set that was sent to me is not the same as the original wires that I took off the car.
Maybe, but not sure i would have any faith in some brands that's all, im picky sometimes, warranty or not. If anything it would be thought materials would be better now then 28 years ago, eh who knows. The car may not see the miles anyway to really know. Im sure it will be fine. Just my experience. im sorry if i offended your choice, my coming across via text tends to look brash. No harm intended.
You know, I got curious about the previous resistance measurements I took by comparing the new Delco set with the Carquest Premium set. You can look at my numbers in the previous post in this thread and see that the new Delco wires have double the resistance when compared to the Carquest Premium.
Anyway, I decided to check the resistance of my original AC Delco wires with 27 years and 65k miles on them. I was surprised to find they have pretty low resistances. Here’s a comparison
The longest original Delco wire. 1699 ohms
The longest new Delco wire. 9900 ohms
The shortest original Delco wire. 1051 ohms
The shortest new Delco wire. 5900 ohms.
Question; Do ignition wires lose resistance with age and use? If anything I would assume they might gain instead of lose.
If they typically do not lose resistance over time, I’m concluding that the new AC Delco wire set that was sent to me is not the same as the original wires that I took off the car.
It all depends on the type of core used, they vary greatly, when i buy performance wires, they list the ohms of each part number sets. one doesn't mean the other is bad. carbon core/fiber core, and some are solid core. all have different ohms from what i have observed. the solid core stuff is more like race car parts, it has to do with radio interference. i never worried about it. if i like the wires, they fit well, they get installed. Some sets we buy are almost $250, double insulated with jackets, heat shrinked to the ends. bullet proof stuff. Wires mainly go bad from oil leaks and abrasions.When loomed properly and stay dry they last a long time.
No offense taken whatsoever. It just that I’m one with growing skepticism about assuming quality based solely on a label. More and more as time goes on.
They’re on a mission to abolish internal combustion engines right? So why would they really give a crap about making good quality long lasting parts? Maybe they still do, I don’t know
I just got my new wires installed on my 93. I went with acdelco premium 7mm. While I think they are fine and will last a very long time, they do not seem to have the same quality as the OEM wires. They cut down costs and made some of the similar length wires identical length. Again it’s “fine” but you have to adjust the loom slightly to accommodate. also I’m sure the materials are better now but the originals seem a bit more substantial.
This is really not a big deal but my point is the “branded” parts are not really “OEM” anymore. You have to decide who is using good quality wires and ends.
Ignition wire replacement
