correct spark plug for L98?
06-04-2009, 08:25 PM
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Car: 87 Formula 350
Engine: 350tpi
Transmission: TH700R4
Axle/Gears: 3.23 limited
correct spark plug for L98?
I've been google'ing and even looked up the part number on rockauto, but I'm confused.
the local autoparts store gave me Bosch Platinum HR9BP (installed now), my service manual says AC R46TS and rockauto lists AC Delco R43TS.
what's the right one? all of the heat ranges are different.
I ask because when I rev my engine and under hard accelleration the engine pops out of the exhaust rediculously, sometimes when I accelerate WOT it will reach a certain RPM and pop so much it hardly accelerates for a second then will pick back up.
For the first 2 minutes that the engine starts up, it revs up fine. Idle is fine, but the idle hunts when it's warming up.
the local autoparts store gave me Bosch Platinum HR9BP (installed now), my service manual says AC R46TS and rockauto lists AC Delco R43TS.
what's the right one? all of the heat ranges are different.
I ask because when I rev my engine and under hard accelleration the engine pops out of the exhaust rediculously, sometimes when I accelerate WOT it will reach a certain RPM and pop so much it hardly accelerates for a second then will pick back up.
For the first 2 minutes that the engine starts up, it revs up fine. Idle is fine, but the idle hunts when it's warming up.
06-05-2009, 01:00 AM
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Car: 1989 Camaro IROC-Z28
Engine: Rebuilt 350TPI (see sig)
Transmission: is being replaced...
Axle/Gears: 20 year old G92 Borg-Warner 3.45
Re: correct spark plug for L98?
Sounds like you need to adjust your timing a bit...
As far as spark plugs go all I know are Delcos cuz thats all I use and both the R46TS and R43TS is correct for the L98 but the heat range isnt important enough to cause backfiring unless you are way off so I would look into your timing. I use R42TS in my car because I have higher compression. the R46TS in your service manual is because they wanted the motor to burn hotter to help emmisions but R43TS is the common replacement plug.
hope this helps
As far as spark plugs go all I know are Delcos cuz thats all I use and both the R46TS and R43TS is correct for the L98 but the heat range isnt important enough to cause backfiring unless you are way off so I would look into your timing. I use R42TS in my car because I have higher compression. the R46TS in your service manual is because they wanted the motor to burn hotter to help emmisions but R43TS is the common replacement plug.
hope this helps
06-05-2009, 06:00 PM
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Car: 1989 Iroc-z
Engine: 5.7L 350
Transmission: 700r4
Axle/Gears: Stock 2.77 posi
Re: correct spark plug for L98?
Take what you have in there and throw them away....I'm running R43TS with 10 to 1 compression, ac delco all the way. Unfortunatly like above said, your backfiring problem is probly not the plugs. Check timing and injectors...
06-05-2009, 06:33 PM
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Car: 1985 Camaro and 1996 Mustang GT
Engine: 350 4bbl/281
Transmission: 700R4/4R70W
Axle/Gears: 9" rear/8.8" 4.10
Re: correct spark plug for L98?
i have always done best with NGK TR-6 or TR55's plugs
06-06-2009, 06:22 AM
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Car: 92 GTA/ 00 TA
Engine: 383/350
Transmission: 700R4/T-56
Re: correct spark plug for L98?
I run acdelco r44ts in one of my birds and acdelco 41-6something in my "toy".
AC Delco all the way.
AC Delco all the way.
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