FAQ: Which Spark Plugs & Ignition Wires should I use?

Can't really know the correct heat range based on mods alone, but based on your list, I would guess AL104s would work fine. Looking at your boost level will tell what range to use (see Page 1 of this thread). Electrode material is only relevant regarding the durability level you expect from the plug. The heat range is the same with copper, platinum, or iridium.

You have to make a choice: do you want the best performance? Or, do you want the best longevity? Part of having the best performance involves scanning for boost and KR, then selecting the coolest plug you can run without fouling. One option could be to use copper ($10) as your test mule, then switching to platinum/iridium after you know if the heat range works in your set-up.

All of this has been discussed several times in this thread. If you read through, you'll have a better understanding re: platinum vs. iridium materials, for example.

Alright thanks! I think going with the copper 104s is a good plan, and if they foul out then it was a cheap gamble. Better to use the coppers as a test mule than the more expensive platinums or iridiums.

Does anyone recommend any spark plugs wires that aren't as expensive as the AC Delcos? Would some cheaper ones from Napa be decent? would these be okay?
cheaper
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=MPW2902_0166239606&An=0+599001+101995+50008+2008026&Ar=AND(P_RecType%3aA)
not as cheap
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?A=BEL700431_0141520683&An=0+599001+101995+50008+2008026&Ar=AND(P_RecType%3aA)

Not sure what the prices are for those NAPA parts, but are you really worried about paying $33 for a proven a product?

http://www.rockauto.com/catalog/raframecatalog.php?carcode=1303322&parttype=7228

AC Delco/Delphi wires will last about 100k miles. That's about 3 cents for every 100 miles of driving. Still seem expensive?

The prices are 13 and 28, the only reason i didn't want to get the AC Delcos were because i wanted to get this project done this weekend and i would have to buy the AC Delcos from the dealership at 69 bucks.

RidzRiv wrote:

The prices are 13 and 28, the only reason i didn't want to get the AC Delcos were because i wanted to get this project done this weekend and i would have to buy the AC Delcos from the dealership at 69 bucks.

A supercharged engine with a .060 plug gap demands a great deal from the ignition system, especially under boost. Buying cheaper wires is not the way to go. The AC wires are excellent, and by far the best for this car.

where can u buy a good set of 10 or 12 mm wires ? what about upgraded coils?

2000ws6transam wrote:

what about upgraded coils?

stock coils on an L67 produce higher voltage than L36 stock coils AND the aftermarket "MSD" coils for 3800s. What makes you think you need even _higher_ output?

stock wires are also good enough, unless you are building a 400+hp engine AND are having interference/heat/breakup issues.

ah, my name is daryl, and im officially an addict of rivieras and boost ( use to despise power adders until i bought my 98 riviera). ok so... i want to run a 3.5 with MPS, a plog, downpipe, and a CAI, how many steps colder plugs do i need (note. i may as well get the car tuned because im weary of just putting things on). i was told not to go to a 3.4 unless i put rockers on etc. which is fine id rather start of little by little and be safe... further down the line, i was actually considering a turbo kit. ive driven my friends 04 monte ss with out a supercharger( im guessing an L36) but had a cartuning turbo kit intercooled with methanol.. that car pulled like nothing ive ever been in lol.. anyways enough babbling. how many step colder plugs should i run?

highwaywarrior wrote:

ah, my name is daryl, and im officially an addict of rivieras and boost ( use to despise power adders until i bought my 98 riviera). ok so... i want to run a 3.5 with MPS, a plog, downpipe, and a CAI, how many steps colder plugs do i need (note. i may as well get the car tuned because im weary of just putting things on). i was told not to go to a 3.4 unless i put rockers on etc. which is fine id rather start of little by little and be safe... further down the line, i was actually considering a turbo kit. ive driven my friends 04 monte ss with out a supercharger( im guessing an L36) but had a cartuning turbo kit intercooled with methanol.. that car pulled like nothing ive ever been in lol.. anyways enough babbling. how many step colder plugs should i run?

BTW I strongly recommend getting it scanned before you change pullies. Many stock cars have KR, adding the pulley will compound that into bigger problems. If you do have KR find out why and fix it first. Could have leaky fuel injectors, clogged fuel filter, vacuum leaks, bad LIM gaskets, many other possibilities and you could have a decent amount of KR right now! So there is a balanced approach to this. Make sure things are running at their peak before you start throwing mods on there!

definitely a good idea, what tool do i use?

For what you are thinking about mod-wise I recommend Autolite AL104 copper plugs (no platinum or iridium). These should run you about $10 at thx local parts counter.

awesome thank you

I just bought my autolite 104s from napa and the guy that worked there gave me damn near 25 minute lecture on how hey are wrong for my 97 rivi and i shouldnt get them and to get ac delco or champion .. Sheeesh

Take those plugs out after 20k miles and show the NAPA guy how clean they are.

can anyone tell me if the sparkplugs om my 97 riv. will be any problem changing them all out? Someone told me that one of the plugs in the back was very hard to get out & put back in. They said that you would have to raise the engine up a couple of inches?? Is this true?? Thanks Birdogmike

No, they're not very hard. If you're a big guy, it helps to remove the passenger side hood strut for better access. Smaller folks can just squeeze through the strut and lean over the fender and back of engine.

Some have better luck going from underneath, but I have tried this and find it easier from the top.

Rockauto has two part numbers for the ACDelco wires listed.  A quick "Google" didn't make much sense of the difference, although another brief forum post elsewhere yeilded a comment that one set was 7mm and the other 8mm.

Do we know which is the correct/best set?  Based on the prices quoted in this thread, I'd guess the 626D for ~$33 is the correct choice, but wanted to check before ordering.  


ACDELCO Part # 9626D  {#88862389}
  WIRE KIT,SPLG   
$26.79  
 
ACDELCO Part # 626D  {Click Info Link for Alternate/OEM Part Numbers12074048, 12074087, 19154581, 626F}
  WIRE KIT,SPLG FRT GREASED BOOT   
$32.89


Also, I've read this whole thread and likely am going to go with the 104 plugs as I am in the throttle pretty regularly, although the engine is stock for now.  But I put 25-30k miles on a car a year, and plan to change the plugs annually.  Would the copper 104s be good for this application, or the irididium?  Based on the prior posts, it sounds like the copper 104s lifespan is right in this mileage zone.  I like the coppers as they are signficantly cheaper

Thanks,
Al

The copper plugs will do just fine if changed around those intervals. I don't really see a point in going to 104's if the engine is stock, but it won't hurt anything.

You could go with either plug and probably have the same result. The iridium more expensive plugs will last longer (if you've read the thread, you know I prefer plugs that don't last for maintenance reasons).

The 104s won't make an improvement unless you're seeing KR or on the verge of seeing KR. Mildly modded and some stock engines see a little knock when at WOT under load or at high RPM. Even then, the gain is very small if any. They're just plugs. But once you are building more boost you want a plug that runs cooler to prevent pre-ignition under boost, like the 104. You don't want a sharp, hot electrode like on an iridium or platinum plug. There are some cooler-running iridium plugs, but I don't like paying for them.

Thanks, I was leaning toward the copper plugs but simply wanted to be sure of their lifespan as I don't want to have to change them more than once a year since my annual mileage is around 25-30k. 
 
I don't have any preference for the iridium or platinum, especially since they cost so much more.

I'll likely try the 104 or 605 and see which plays well with my car.  I had a bit of a fight with knock on my 95 Roadmaster recently which turned out to be plug age/wear related, and it was highly sensitive to ambient air temp.  Going into our hottest time of the year, I just thought I'd try the cheap copper 104s and see if they stay clean.  If not, I'll step back to the 605.

Once I have a good baseline with the car I may drop a pulley size, but that's a ways off for now as I'm still doing some basic maintenance items.



Any idea on the wire set part #s question?

Thanks
Al

For about 9 years I drove 25-30k miles per year with only AL104 plugs in my Riv. They needed changed at almost exactly that interval. Gaps had worn from .058" to about .070" in that time.

On the wires, I wouldn't chance it with RockAuto. Try these and be sure:

http://www.trademotion.com/parts/1998/BUICK/RIVIERA?siteid=214858&vehicleid=1303322§ion=ELECTRICAL&group=IGNITION%20SYSTEM&subgroup=IGNITION%20SYSTEM&component=CABLE%20SET

(sorry, you'll want the 1995 versions, if different)

AA wrote:

For about 9 years I drove 25-30k miles per year with only AL104 plugs in my Riv. They needed changed at almost exactly that interval. Gaps had worn from .058" to about .070" in that time.

On the wires, I wouldn't chance it with RockAuto. Try these and be sure:

http://www.trademotion.com/parts/1998/BUICK/RIVIERA?siteid=214858&vehicleid=1303322§ion=ELECTRICAL&group=IGNITION%20SYSTEM&subgroup=IGNITION%20SYSTEM&component=CABLE%20SET

(sorry, you'll want the 1995 versions, if different)

www.magnecor.com makes very good wires but they will cost more.  I have about 150K miles on my set, no issues - no failures.

Thanks, I found our "parts FAQ" and that matched up with one of the alternate part numbers for the more expensive set.

Well I'll be a sonuvabitch. Knowing good and well what could happen, I went and tried NAPA's Beldon brand ignition wires on my Grandpa's '96 SC Riv. He'd been experiencing that pulsating hesitation we commonly see with these engines around 100-150k, when the wires start to wear out. I knew it was the wires, so I drove 300 miles to do the job, but I didn't have time to order the OEM Packard/Delphi wires, so I bought NAPA's "best". The sales clerk told me he'd "never seen a pair returned for any reason." They weren't cheap, and I thought they would be good enough for Grandpa.

Well, they weren't good enough. After a month of trouble-free driving, got a call. Same problem again. He got it scanned - multiple misfires. The guy at NAPA is about to get his "first" returned set of Beldons from us!

I can't believe it. We preach and preach about OEM wires being the best, and I thought maybe this time I'd get lucky with a solid brand from NAPA. Nope. Sorry Grandpa, and shame on me! I'd say lesson learned, but I knew better.

    

Order placed. Heading out to fix the problem when they arrive. So frustrating!

PS - spark plugs looked good as new. We re-gapped them and reinstalled. The car ran completely free of misfires for 4-5 weeks.