Platinum or Iridium plugs on stock 82 Vette?

[Robenstein]

As everyone knows, changning plugs on a vette can be sort of a pain. Well I got suckered into helping my friend with his 82 corvette change his...more like I am going to end up doing it. It has standard copper plugs in it now. I was thinking since he drives the heck outta this thing I dont want to do it again for a long long time or never and thought about having him buy platinum or iridium plugs for it. I know these work well in newer cars but how do they hold up and perform in older GM HEI small block chevy motors?

If they work well Im gonna do it on my old 86 SS Monte as well when its due.

 

[RamFan]

Let me be clear that I know practically nothing when it comes to plugs. However, from what I've seen on the net I am under the impression that using the OEM plugs or OEM type plug are the best way to go. If it came with copper from factory, use copper. If it came with platinum, then use platinum.

Not sure how valid this is but it is what I see the most of.

 

[Robenstein]

I try to stick with OEM brands. So I will put AC Delco's in it but if I can get longer life out of a plug, Im all for it.

 

[barlowc]

The folks on one of the Vette forums (e.g. corvetteforum dot com) will likely have a good recommendation.

 

[Robenstein]

Well I just wondered if someone on here had used it in any Small Block Chevy motor with HEI so I do not have to register and sign up for a forum im going to visit once.

 

[brentalan]

I use Iridium in my '88 Caprice and it works fine. I'm sure platinum would too.

 

[Knox]

I'd stick with copper, the platinum and iridium plugs where made specifically for Coil on plug and other High output systems.

Direct from autolite Q&A

Q:What are the different types of spark plugs?
A:Spark plugs are available in different thread sizes and heat ranges. The various sizes and heat ranges are required to match engine requirements. They are also available with premium features such as platinum tipped electrodes for long life and small diameter (fine wire) electrodes for improved ignitability

None of the "premium" features apply to an 86 vette. Plugs last a long time, as long the vehicle is tuned correctly. The thinner electrode might make a difference if you had extreme compression or where running boost.

Hears a side by side video of NGK plugs.

http://www.youtube.com/watch?v=tS4MV2pELyU&feature=related

I imagine the electrode will be fouled and the porcelain burnt by the time you have to change them next. There's no magic plug to stop that.

 

[Quest]

platinum plugs will run on engines that specified for copper core plugs, so long as your ignition system is "strong" enough to create consistent sparking.

In other words: if your vette runs on electronic (solid state) ignitions, then you can retro it with iridium or platinum plugs w/o fear.

To all others: platinum or iridium plugs were previously considered extremely exotic plugs, destined to be used in exotic race cars, grand-prix or F1 varieties where cost is not an object. As technology advancement and also the ever so stringent emissions regulations in NA gasoline emissioned vehicles, the call for platinum or iridium plugs on mass-produced vehicles is to help in providing consistent sparking over an extended period of time (when compared to copper core), so that vehicle manufacturers can meet the stringent emissions requirements (esp. OBD-II types with lots of controls and monitoring on the emissions side: pre/post cat o2 sensors, etc.)

There's absolutely nothing exotic about platinum or iridium plugs other than cost and manufacturers can now venture further into the takes of rigging their factory vehicles stock with either one and will be guaranteed that the vehicles will still meet EPA and federal emissions standards 5 ~ 8 yrs down the road (past factory warranties). Try that with copper core plugs and you'll be guaranteed with a CEL message in about 3yrs worth of service.....

Case to the point: while everyone in the small engine section of the forum aware of how a Briggs and Stratton engines would generate HT sparking (rotating magnet to induce HV on a coil), haven't you noticed that on Wallymart's shelf they now carries high end, B&S relabelled platinum plugs for those lowly flat-head mower engines?

Q.

 

[Robenstein]

Well the last set in my properly tuned Nova lasted a whole 20k miles. But those are a piece of cake to replace.

 

[mpvue]

iridium and platinum plugs don't provide a better spark, they just last longer.
'82 vette, wasn't that a low output cross fire injection small block? I'd just put in whatever and call it a day.

 

[tomcat27]

Platinums and Iridiums will work just fine with your car - and last alot longer. Plats were not specifically designed for Coil On Plug.... although with a C.O.P. (or any ignition with one coil total OR one coil per plug) you only need a single platinum. with a waste spark system with one coil for every two plugs you need a double electrode. (*with the exception of some dual plug engines line the late model Dodge Hemi) It all has to do with the direction of the spark - the most wear occurs on the positive electrode of the plug.

I've used plats on many cars with plugs that are difficult to reach - and also on Durango's with the Hemi. (think 16 plugs on an engine that is stuffed back pretty far)

 

[Errtt]

I changed my motorcycles to Iridium plugs. I noticed last winter easier starts and smoother idle on those cold winter mornings. I pulled them again recently to see how they were doing after summer use. For the miles on them, they are cleaner compared to when I was running standard plugs before for about the same mileage.
Before when using standard plugs, I was changing them once a year needed or not. As good as these Iridium look, I'm keeping them in instead of changing them yearly.

Unconfirmed - but I was told that the Iridium is easier to fire and bikes (at least mine) don't have a robust high energy ignition system. A buddy of mine has been using them and he talked me into trying them. No regrets except I wish I had done it sooner. He claims a little better mileage in his bike - I don't track mine so I don't know.
On the wife's bike, she says it's smoother and a little more responsive at highway speeds, and smoother at sitting idle.
Someday I'll get the itch and maybe throw Iridium's in the car and 2 SUV's.

 

[Knox]

+1 It's not something exotic.

Also i had meant to say, 82 'vette or 86 monte carlo.

 

[Robenstein]

Yeah a small block is not exotic, its the task that makes me want to use a plug that lasts longer so I wont have to deal with it as often. The few bucks a plug is worth a nice sunny afternoon here and there I can be out for a nice drive, motorcycle ride, or BBQ instead of cranking on wrenches.

 

[mechtech2]

What is up with everyone mentioning copper??
A plug can be plain steel, platinum or iridium tipped, and be copper cored.
Who cares how the heat range and resistance specs are met??

I'd use a premium double tipped plug in that car, for sure.

 

[oppirs]

Stick with the copper plugs. I had a major issue trying to remove the plugs on my '89 caddy. Rusted so much, they broke at the hex nut!

If that Vette is not driven much. Better to replace the plugs every "x" years. Unless like you said you never want to change them again, use Iridiums. The Iridium plugs in my GMC looked so good @80k. I think I could have gone to 150k mi or more. But I didn't want them rusted in after 9 years.

 

[SteveSRT8]

Originally Posted By: mechtech2
What is up with everyone mentioning copper??
A plug can be plain steel, platinum or iridium tipped, and be copper cored.
Who cares how the heat range and resistance specs are met??

I'd use a premium double tipped plug in that car, for sure.


This. I also agree, it's nearly comical.

Pick your plug based on how often you want to fool with it.

Use some anti sieze if you have "head anxiety".

Then go for a drive!

 

[mpvue]

Originally Posted By: tomcat27
...with a waste spark system with one coil for every two plugs you need a double electrode.

not always. the saturn 1.9 has a waste spark system 2coils/4plugs and they work best w/ OEM traditional plugs. they actually don't run well at all w/ platinum/iridium plugs.

 

[meep]

Originally Posted By: tomcat27
Platinums and Iridiums will work just fine with your car - and last alot longer. Plats were not specifically designed for Coil On Plug.... although with a C.O.P. (or any ignition with one coil total OR one coil per plug) you only need a single platinum. with a waste spark system with one coil for every two plugs you need a double electrode. (*with the exception of some dual plug engines line the late model Dodge Hemi) It all has to do with the direction of the spark - the most wear occurs on the positive electrode of the plug.

I've used plats on many cars with plugs that are difficult to reach - and also on Durango's with the Hemi. (think 16 plugs on an engine that is stuffed back pretty far)


^^this^^

use what you want. the HEI will handle it just fine.

ONE NOTE that hasn't been discussed. ALL plugs will generally spark just fine. There are cases (I've known one or I wouldn't believe it) where for one reason or another a plat plug didn't work well in a "copper" car.

People come up with all sorts of garbage ideas why. One is that platinum has more resistance than copper. Phooey! The plugs we all use are resistor plugs. Wires are in the k-ohm range... 0.5ohm or whatever small amount introduced at the tip will have NO effect in a high volt / low current circuit such as the high-tension secondaries.

NOW-- what CAN wreak havoc is how the newer vehicles zap the plug and then READ the reflected signal back from the plug circuit in the ecu to determine combustion health. I'm not making this stuff up. It was brought up on bitog 2 years ago and I read the links and yes, the ECU's on some (maybe more now) vehicles also use the spark plug as a sensor as well. Since we are talking milli and micro seconds in which these reads occur, different resonant properties of certain plugs could be an issue in modern cars.... SOME modern cars.

But in an old-school vette--- use whatever you want.

My accord ran bosch plats a-Ok. my brother's wouldn't idle with them.

My Town and Country runs bosch +2's just fine, while most mopar internet guru's condemn any mopar engine with platinums to a "don't talk to me status."

My jeep shipped with NGK v-power... in a world where Mopar says "Only Champion may enter here." I installed champion plugs and now 10k later it has a single cylinder stumble on tip-in. It gets NGK or Bosch next if this gets worse.

A lot of folks need something to believe in.

Mike

 

[MrCritical]

Five letters that will ruin your Corvette day...B-O-S-C-H. Go back with OEM's, or if they list an improved plug available.