sparkplugs

[bvectra]

want to put new plugs and want to know what people use I had e3 in but have to replace them:flag:

[ssrszz4]

I was wondering about using NGK iridium in my "90. ?? I really like these plugs and have used them where ever I can.

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[ghlkal]

I use AC 41-602 plugs. They seem to work fine and they are inexpensive enough that I can change them out every year or two depending upon how many miles I put on the Z.

[Dynomite]

I was wondering about using NGK iridium in my "90. ?? I really like these plugs and have used them where ever I can.

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For my 91' NGK Iridium BKR5EIX Eagle
Gapped .043".
I will use anti-sieze on stainless steel bolts, spark plugs, and header bolts (Permatex Anti-Sieze 133A).
http://i287.photobucket.com/albums/ll142/dynomite007/91%20ZR1/NKGIridium.jpghttp://i287.photobucket.com/albums/ll142/dynomite007/91%20ZR1/Permatexantisieze.jpg

Starter, Starter Relay, Wiring Harness, Battery, and Plugs Tricks (http://forums.corvetteforum.com/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-3.html#post1581564085)

[ghlkal]

I sent a message to Marc Haibeck since I plan on changing mine this winter. I'm sure he wouldn't mind if I share his response ...

- - - - -

The 41-602's are very good. I gap them at .035". They are inexpensive and last about 15,000 miles.

The best plug is the 41-801. It's a double platinum with a smaller pointy electrode. The smaller electrode has a better electric field for a .045" gap that might contribute to a better idle. They are expensive at about $70 a set but they will last about 50,000 miles.

[Roadster]

I already have a few sets of the 41-602's, but decided after reading this, why not pick up a set of the 41-801's. Went on ebay and found some very inexpensive compared to what was mentioned in the text.
When I spoke to the PO before the previous PO, he informed me that he changed out the plugs at 55,000 miles. I am now at 68,800 miles, so I will probably change them out this year......

[Hog]

The mail in rebate for all Delco plugs is in effect for all of 2017.
41-801 the double Platinums are $5.20 a hole, so the $2.00 rebate brings that down to $3.20 a hole.

Iridiums are discounted $3 per plug
Double Platinums $2.00
Rapidfire Performance Single Platinum ($1 per plug)
Professional Conventional ($.50 per plug)

The 41-602's are $1.44 or $0.944 a plug after the rebate.

I just bought six 41-834 plugs for my Atlas Inline 6 cylinder, and they were $10.00 a piece. Not cheap but they cover GM's 100,000 mile warranties these days.

https://www.rockauto.com/Images/CurrPromoFiles/DelcoSparkPlugs2017.jpg

[ghlkal]

The mail in rebate for all Delco plugs is in effect for all of 2017.
41-801 the double Platinums are $5.20 a hole, so the $2.00 rebate brings that down to $3.20 a hole.



Nice find.

Thanks :-D

[Hib Halverson]

The OP was asking about E3s. They are crap. Don't waste your money.

If budget is tight, consider the above mentioned ACDelco discount/promo price.

If you want really good spark plugs and are not too concerned about price, for the last 15 years I owned Barney, my 500-hp '95, I used the Denso IT-22 (two sets) exclusively. Great performing plug with pretty darn good plug life. I also use the IT-22 in my LS6 and LS7 engines.

[Roadster]

Found out from Yun that the plugs that I had ordered AC-602 and have and the most recent ones ordered AC 41-801 are the incorrect spark plug type for my 94. Learn something new all of the time. These are all brand new and in the box. I will sell them for a good price plus free shipping if anyone is interested and will also list in the
FS section....

Ordered NGK 7397 Iridium IX TR5IX which are the correct for the 93-95 ZR-1's.
found them for a decent price and local on ebay.....

[Hib Halverson]

Keep in mind that virtually all plug recommendations in catalogs, regardless of manufacturer are, IMO, too hot.

When the 1G LT5 was in final validation back in the late 80s, GM and Lotus specified the FR1LS spark plug, which was in the ACDelco #1 heat range. That offered best performance in all normal street driving duty cycles.

Right as the car was reaching dealers, because of concerns about "pre-delivery plug fouling" and its effects on customer satisfaction, the spark plug spec was changed to the FR2LS, which was the one range hotter #2 heat range. The only reason GM did that was to avoid warranty problems with any pre-delivery spark plug fouling which might occur and addressed some customer complaints of new car with fouled plugs. When ACD started publishing spark plug data, it listed the FR2LS and all the other plug makers followed that lead, i.e." NGK lists their 5 heat range, Denso lists its 16 heat range and so on and so forth.

No one in the C4 ZR-1 community needs to be concerned with pre-delivery fouling and use of the 2 heat range plug, unless their ZR-1s are never driven normally and are subjected to duty cycles such as frequent starts-without-warm-up, trailered car-show use, short trip street driving only use with no high-rpm or high load use.

Anyone who drives their ZR-1 normally...ie: seldom or never any starts without-warm-up, should go to a colder plug. Such as:

ACD #1 heat range
NGK 6 or 7
Denso 20 or 22.

The reason you want a somewhat colder plug is that hot plugs make the engine more prone to detonation under high-rpm/high-load operation.

For the last 15 years I owned Barney, my 500-hp '95, I used the Denso IT-22 exclusively. It worked very well on the street and in mild racing applications. Before that I used the NGK 7 heat range.

The NGK TR5IX is too hot a plug unless the car is a show car and never is driven normally. You need at least a TR6.

[Roadster]

Anyone who drives their ZR-1 normally...ie: seldom or never any starts without-warm-up, should go to a colder plug. Such as:

ACD #1 heat range
NGK 6 or 7
Denso 20 or 22.

The reason you want a somewhat colder plug is that hot plugs make the engine more prone to detonation under high-rpm/high-load operation.

For the last 15 years I owned Barney, my 500-hp '95, I used the Denso IT-22 exclusively. It worked very well on the street and in mild racing applications. Before that I used the NGK 7 heat range.

The NGK TR5IX is too hot a plug unless the car is a show car and never is driven normally. You need at least a TR6.

Hib, I can return the TR5IX plugs which are arriving today. You mention above that I need at least a TR6, I can also get a TR7 that you have also used. So which one do you recommend. I drive just under 5,000 per year.
I now have 68,000 + on the 94, the plugs were changed by a PO @55,000 miles. The plugs that are in there are AC 41-963
Thanks for the info.....appreciated.

[mike100]

Factory heat range is usually ideal for the low speed emissions testing, but maybe I will try an alternative at one range cooler someday because you can definitely get some pinging on CA 91 octane gas in the summer.

[Hib Halverson]

Hib, I can return the TR5IX plugs which are arriving today. You mention above that I need at least a TR6, I can also get a TR7 that you have also used. So which one do you recommend. I drive just under 5,000 per year.
I now have 68,000 + on the 94, the plugs were changed by a PO @55,000 miles. The plugs that are in there are AC 41-963
Thanks for the info.....appreciated.

When I used NGKs, I used the 7 heat range. Of course, back then the TR plugs didn't exist in the NGK line but, yeah, if you are partial to NGK, then you need the TR7.

[Roadster]

When I used NGKs, I used the 7 heat range. Of course, back then the TR plugs didn't exist in the NGK line but, yeah, if you are partial to NGK, then you need the TR7.

Sounds good to me, because the TR7IX are on the way. Returned the TR5IX.
Thx, appreciated.....

[Hib Halverson]

Factory heat range is usually ideal for the low speed emissions testing, but maybe I will try an alternative at one range cooler someday because you can definitely get some pinging on CA 91 octane gas in the summer.

Regardless of what plug you run, you are going to get spark knock on 91-octane gas because GM calibrated for 93.

When I had my 95, because I was at sea level, the only time I never saw KR at WOT was when it was really cold out. Once it warmed up outside I'd start to see KR. If it was a hot day I'd get a consistent 5-7 deg. spark retard.

What the colder plug will do is keep the spark plug from making the knock situation worse, if the detonation incident occurs under wide open throttle/high-load conditions.

[Paul Workman]

For what it's worth...

41-602s in Pete's Green Monster

https://www.youtube.com/watch?v=SFNFOhGGlR4

41-602s after one year in my 500+ LT5, gapped at .035

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/AC%20Delco%2041-602s%20with%20aprox%202800%20miles_zpsrpb9nrx1.jpg (http://s185.photobucket.com/user/6PPC_bucket/media/tech%20files/AC%20Delco%2041-602s%20with%20aprox%202800%20miles_zpsrpb9nrx1.jpg .html)

[rush91]

For what it's worth...

41-602s in Pete's Green Monster

https://www.youtube.com/watch?v=SFNFOhGGlR4

41-602s after one year in my 500+ LT5, gapped at .035

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/AC%20Delco%2041-602s%20with%20aprox%202800%20miles_zpsrpb9nrx1.jpg (http://s185.photobucket.com/user/6PPC_bucket/media/tech%20files/AC%20Delco%2041-602s%20with%20aprox%202800%20miles_zpsrpb9nrx1.jpg .html)


For us un-mechanical folks, what am I looking at? Spark plugs obviously, but are these good looking plugs for a year worth of use? Were they fouled or anything, and what does gapping do? I'm wanting to change my plugs, would they need gapped or is that for modified engines?

[ssrszz4]

They look near perfect

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[S.hafsmo]

For us un-mechanical folks, what am I looking at? Spark plugs obviously, but are these good looking plugs for a year worth of use? Were they fouled or anything, and what does gapping do? I'm wanting to change my plugs, would they need gapped or is that for modified engines?
Some photo comparisons if you scroll down a bit.

https://www.autohausaz.com/html/spark-plugs_spark-plug-wires.html

[Paul Workman]

For us un-mechanical folks, what am I looking at? Spark plugs obviously, but are these good looking plugs for a year worth of use? Were they fouled or anything, and what does gapping do? I'm wanting to change my plugs, would they need gapped or is that for modified engines?

As ssrzz4 said: "Near perfect". My point is you don't have to go to some exotic, pricy plugs for good performance. These plugs are inexpensive (about $2 ea.) perform extremely well (as Pete's car and photo demonstrates).

These plugs could easily do another 3-6k miles (like last season), but plugs are so easy to change on an LT5, one could put in a new set each season (as I usually do).

The space between the electrodes is the "gap" which the electrical charge must jump resulting in spark that ignites the very hot, compressed air/fuel mix.

The gap can be increased or decreased by bending the (prong) electrode closer or further from the center electrode.

The amount of gap is a recommendation that comes from various sources. But, generally the larger the gap, the longer and hotter the spark. A feeler gauge (you should invest in one, btw) is used to measure and set the initial gap; which increases with use with mileage and other conditions.

Difficulty in reaching/replacing the spark plugs on some engines, and with the demand for longer maintenance intervals. resulted in the recent use of exotic rare earth materials. These plugs offer the advantage of increased durability (longer change intervals) AND significantly larger spark gap which results in a hotter spark.

So, why not use exotic plugs and reap the benefit of "hotter spark" and longer life?

Well, plugs work best when new, but their performance begins to deteriorate from the first moment they are put to use. Changing plugs every season means my plugs are always near the top of the performance curve for the entire time they are in the motor. And, it "forces" me to check how the motor has been running for the past 3-4k miles or so. (Rare earth plugs may go "50,000 miles" before performance deteriorates to the point of changing them out of necessity. But, why put up with marginal performance near the last 1/3 of their life...maybe 20k miles or more?:dontknow:)

Not trying to sell you on plugs. Use whatever you think is best. But, my (500+ hp) motor obviously likes the plain ol plugs I'm using, and the video of Pete's car doing an 11.3x quarter mile does too. (BTW, that video is old: since then he's cut an 11.04 sec quarter with that stock-bottom 350 LT5 using those 41-602s!) Point is: you don't have to spend an arm and a leg for good plugs...unless you want to.

[secondchance]

you don't have to spend an arm and a leg for good plugs...unless you want to.[/I]

I just want some iridium on my car. That's all...

I use to run AC Delco Rapidfire when these were copper plugs with fluted electrode. LT5s ran great with these plugs and these were good for 12,000+ miles. Somewhere along the line, GM kept the name but changed the plug design. That's when and why I went to iridium plugs. Iridium plugs are pain because when you gap them you can easily damage the electrode if not careful unlike conventional plugs.

[mike100]

...

The amount of gap is a recommendation that comes from various sources. But, generally the larger the gap, the longer and hotter the spark....

'longer' in distance jumped by the spark, but the burn duration will be shorter in time as some of the energy was used to jump a long air gap. old fashioned automotive analyzers used to have inductive scope pickups for wires and triggered off the coil negative. It was a pretty cool way to look at some before and after on ignition tune ups or mixture problems.

An electrical spark will jump a bigger gap in a vacuum vs sea level and going to pressure extremes, high compression or turbo cars usually run narrower gaps to insure proper light off....either that or hotter ignition systems.

[XfireZ51]

problem w increasing the plug gap is that it puts a strain on ignition coils.
The LSx coils have the additional uumph to jump a larger gap like .050".
At that gap, I found that my motor idles more smoothly but high rpm operation could suffer.

[Hib Halverson]

For my 91' NGK Iridium BKR5EIX Eagle


Car must be a total waxer.
:)

Even the LT5 plug called for by ACD back in 90, the FR2LS crosses to the NGK 6 heat range. The NGK 5 heat range is like putting an FR3LS into the engine, which is one range hotter than what the book calls for and two ranges hotter than the heat range Lotus specified during development.

[XfireZ51]

Hib,

I'd been using NGK6E for quite a few years, but recently went to NGK5E after inspecting the ground strap and doing plug cuts. The 6s were just a bit too cold for my setup.