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Help me choose a spark plug gap!

tntcorvette

Well-known member
Joined
Oct 21, 2002
Messages
604
Location
Chicago, Il
O.K. I just got a set of new spark plugs (A/C Delco FR3LS, rec. spark plug for my afr 190 heads) and im looking for a spark plug gap to compliment my setup.

The ignition is a MSD 6A, MSD GM HEI Coil, MSD 8.5MM Wires, Accel cap & rotor & MSD low resistance rotor bushing & Aftermarket high performance moduel (the one outta M.A.D.)

I got these plugs because they are the ones rec. by AFR for their 190 head, and ran these plugs last year fine with a .040 gap w/o any problems.

Now that i've upgrade the ignition what should I run the gap at?
 
i would suggest a .047 gap this helps in burning all the fuel and keeping the plugs from fouling out. i use this gap in all my rides if i don't use +4 plats most plugs come stock gapped at .045
 
Mic, your signature image is getting a little big. Could you resize it slightly smaller please? ;)
 
tntcorvette said:
O.K. I just got a set of new spark plugs (A/C Delco FR3LS, rec. spark plug for my afr 190 heads) and im looking for a spark plug gap to compliment my setup.

The ignition is a MSD 6A, MSD GM HEI Coil, MSD 8.5MM Wires, Accel cap & rotor & MSD low resistance rotor bushing & Aftermarket high performance moduel (the one outta M.A.D.)

I got these plugs because they are the ones rec. by AFR for their 190 head, and ran these plugs last year fine with a .040 gap w/o any problems.

Now that i've upgrade the ignition what should I run the gap at?


Thanks for the tip!

BTW, you have 88 - 89 rims. The 1990 rims have a different center cap!
 
With that ign. system, set the plugs at .060-in.

Also, I read you have AFR heads along with all that MSD stuff. That leads me to believe you have other mods and probably drive the car fairly hard. If that's the case, the FR3LS is too hot a plug.

I'd be using at least an FR2LS and, maybe even the FR1LS. That said, I think there are better choices than those ACs. I've been using Denso Iridium Powers in all my cars with non-DIS.
 
Hib Halverson said:
With that ign. system, set the plugs at .060-in.

Also, I read you have AFR heads along with all that MSD stuff. That leads me to believe you have other mods and probably drive the car fairly hard. If that's the case, the FR3LS is too hot a plug.

I'd be using at least an FR2LS and, maybe even the FR1LS. That said, I think there are better choices than those ACs. I've been using Denso Iridium Powers in all my cars with non-DIS.


Hib,


what do you exactly mean by too hot of a plug? Please forgive my ignorance on spark plug temps and such. The only reason I got them is because AFR rec. the plugs.

Now that I think about it, the car has been running somewhat hot for the temp up here in Chicago (30's to 50's). It usually gets to 190 real quick then cools down to 170 or so. But I dont know if it is the miniram and its different cooling channels or what because last year I ran a LPE SuperRam system and the same plugs, less the msd ignition and the car ran fine temp wise. Especially the quick heat up and such.

Mabey I should ditch this MSD stuff??? I went with it for the best idle possible, to make sure all the gas is burnt, and to hopefully give me a edge on emissions.

Can I piut the FR3LS in a 94 chevy baretta? I hate to see that spark plug money goto waste......

So which plug should I go with????
 

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