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FR2LS Spark Plugs

  • Thread starter Steel Half-Shafts
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S

Steel Half-Shafts

Guest
In addition to the Rapid Fire #5 Spark Plug changes, I just tried to order a set of the FR2LS OEM Spark Plugs from AC Delco Direct.com and was told they have been discontinued and have been replaced with the 41-602 Spark Plugs @ $ 2.02ea.

The FR2LS plugs have worked excellent in my 90 ZR-1 and assume the 41-602 plugs will perform the same.

Anyone have any info on the plug change? ;help
 

Rob

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Gordy,

I believe I have these installed in my car. I asked for a set of FR2LS and received these at the parts counter. When I get home, I will verify.
 
S

Steel Half-Shafts

Guest
Thanks Rob,
I just picked up a couple of sets from AC-Direct.com.
The 41-602 has a smooth insulator body (for a more positive seal with the spark plug boot I'm told) as compared with the FR2LS which is ribbed design.
The base shell design is slightly different. The nose and tip seem identical.

I've got a couple of e-mails into AC Delco/AC-Direct.com asking about the change. I'll let you know what I hear. :crazy
 
S

Steel Half-Shafts

Guest
Here's AC Delco's response to my e-mail on the 1990 ZR-1 OEM #FR2LS sparkplug change to the new #41-602. :confused

Thank you for writing ACDelco.

The correct part number for your vehicle is #41-602. It has replaced the #FR2LS Spark Plug.

The new plug the #41-602 is a platinum plug while the #FR2LS was a standard plug. The new features focus on changes to the center electrode, the side electrode (also known as the ground electrode) and the insulator.


Thank you for your interest in ACDelco.


ACDelco Customer Assistance
 

Rob

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What is it with AC Delco converting everything to Platinum type plugs and not stating it on their packaging!!! :r :mad

I don't want platinum plugs in my Vette. It didn't come with them, it was happy with FR2LS standard plugs and that's what I want. This really bothers me. :mad
 
S

Steel Half-Shafts

Guest
Posted by Rob.
I don't want platinum plugs in my Vette. It didn't come with them, it was happy with FR2LS standard plugs and that's what I want. This really bothers me.

I agree with you Rob! :dance

I was very happy with the way the FR2LS performed in my ZR.
Now, it appears we'll just have to see how the 41-602 work out :(
 
J

jw461

Guest
I found this out also, which is peculiar, because I'm not sure how I came up with the idea to use that plug in my car. Whenever I needed cheap plugs I used the FR2LS (i.e. dialing in fuel initially to get a car to idle, breaking in motor, etc) in my 3000GT.

Since they stopped making them, I started using FR3LS which are the same plug but one range hotter. If you want, there are aos FR1LS which is the same plug but one range colder. They'd probably be a good nitrous plug, but I don't use them since I just want a car to start and idle whenever I use Delco plugs.

Since we seem to be using the same plugs, if any of you are adventurous, try one of these NGK plugs:

BCPR6ES-11 (0.044" gap)
BCPR6ES (0.032" gap)

For nitrous or boost (I've run up to 25psi):
BCPR7ES-11 (0.044", but you better have an awesome ignition under lots of boost)
BCPR7ES (0.032" gap, which is what most of the fast single-turbo Supras run)
 

Hib Halverson

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Those who do not want platinum-tipped plugs in their LT5s and who are confronted with ACD's discon. of the FR2LS, need to look at either NGK or Denso for non-plat plugs.

Keep in mind that the original LT5 plug was the FR1LS not the FR2LS. The engine was designed with that plug in mind and the FR1LS was released back in 1989 for that application. Shortly before the 90s went on sale, GM, nervous about pre-delivery plug fouling problems, changed the LT5 to a plug one range hotter. FR2LSes are too hot if you drive the car the way it was meant to be driven. No one except waxers who trailer their cars--and, thus, see lots of starts w/o warm-ups or people who drive real easy needs a plug as hot as the FR2LS.

The closest thing ACDelco has now to the FR1LS is the Rapid Fire #9. The original RF9 was a non-platinum plug that nearly duplicated the FR1LS but with some revisions for higher-performance. The current RF9 is a single-platinum, like the 41-602, but it has some additional performance features.

With the discon. of the standard type ACs and the conversion of the RapidFire line to a single-platinum tip, there are no non-platinum tipped ACs for LT5s.

For those looking for the durability of platinum plugs, the 41-602, a single-tipped plat., isn't a good value for the LT5, anyway. The LT5 "waste-spark" DIS needs a double-platinum tipped plug, otherwise the durability advantage of a set of plats is negated. Four of the plugs in an LT5 fire with reverse-polarity. Electrode errosion goes the way of current flow. For that reason, to get the durability benefit of plats in an LT5, you need double plats. Use a single tip plat in an LT5 and you need to understand that the durability of the set of plugs will be no better than that of non-plat. plugs like the FR1/2LS

Actually, I have used double platinum plugs in my LT5 but not ACDelcos. I've used the NGK BKR6EP-11. The NGK double-plats are a different design than the ACDs and are less suceptible to the failure of the bonds between the platinum pads and the center electrode. I've run the BKR6EP-11 with good results.

The sraight/crossover, NGK equiv. of the FR1LS is the BKR6E.

As for Denso, its equiv. to the FR1LS is the Q20RP-U11.

Lastly, it was mentioned that the NGK 7 heat range plugs are good for boosted engines. I've run the NGK 7 and, even the NGK 8 heat range, on the street in LT5s with no problems. I'd recommend the 7 heat range plug for street-driven LT5s that are driven aggressively whether they are stock, boosted or otherwise.
 

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