Spark Plug Info for Drag Race Mopars ?

[cdr]

this is what i run 6993

 

[69 GTX]

Good info guys, thanks.

 

[Canyon707]

I run the NGK V Power Racing Plug R5672A-8 Stock number is 7173

 

[RacerAL]

I run the Champion C61CX (non projected tip) race plug. 13 to 1 with a MSD6 Digital and a MSD pro billet distributor

 

[Mike Gaines]

I run the Champion C61CX (non projected tip) race plug. 13 to 1 with a MSD6 Digital and a MSD pro billet distributor

Thanks Al.

The Champion C61CX is what INDY Cylinder head says to run (with their Aluminum Heads)
on 10.5CR up to 12.5CR

That Champion Cross-references to the Autolite Racing Plug AR3934.

 

[lewtot184]

if your using a flat top piston or a domed piston with a fire slot or plug relief, then a projected tip might make more power. domed pistons that shroud a plug and require a non-projected tip are a power lose.

 

[BigHemi]

In my 14:1 Indy headed 440 I run NGK 4554 (R5671A-8).
I use the same plugs in my 11:1 pump gas hemi when running naturally aspirated. Both gapped at .035" or so.
On nitrous I use NGK 5238 (R5671A-9) gapped at .025".
MSD 6AL and HVC coil.

 

[66Satellite47]

Holly crap .060 !!!

After looking at this thread, I've given some more thought to my wide gap approach. The .060 is what I used in the old days with my drag cars, iron heads, MSD 404 BC ignition. With today's aluminum heads & the better chambers, no domes, I'm guessing the super wide gap may not be really needed. The MSD 404 BC fired that gap with no problem up to 7500+ rpm. But with the flat tops & newer heads I guess that's not really needed. I'll probably shoot for more like .045 next year. Thanks to all for the advice.

 

[lewtot184]

seen some autolite 3921's at wal-mart, $3 a pair. should be equal to a 9 champion heat range and close to a 7 in ngk. cheap race plugs.

 

[actionange1]

Ive run NGK R5672A-8 STK #7173 in my cars for 10 years gapped at 35 with an MSD 6A and a 7AL2 as of late. I have the current set in for 2 years now as I take them out check the gap and when put back in the car doesn't change one bit. Indy 440EZ heads with Max Wedge ports. Best of 9.88 with the Belvedere and 9.75 just scratching the surface on the Coronet

 

[Mike Gaines]

THANKS FOR ALL THE RESPONSE ON PLUGS.

I can now make an informed decision on what I want to run as far as:
1) Brand
2) Type of Plug for that brand
3) Heat Range
4) Gap Setting
5) How often they should be changed

 

[moparmarkk]

spark plugs

THANKS FOR ALL THE RESPONSE ON PLUGS.

I can now make an informed decision on what I want to run as far as:
1) Brand
2) Type of Plug for that brand
3) Heat Range
4) Gap Setting
5) How often they should be changed

Any info for iron heads? Mark

 

[lewtot184]

Any info for iron heads? Mark

in my opinion the j11y was the best iron head plug. they've been extinct for decades.

 

[BigHemi]

I used to run Champion J8C plugs w/ iron 915 heads on a 440 with nitrous.

 

[gtxracer]

I run Accel shorty plugs for header clearance gaped at .045
MSD digital 6
MSD Blaster coil
Accel ceramic wires
MSD Pro Billet distributor
13.3 Comp
VP 112 race gas

 

[moparmarkk]

gtx racer how long do the shorty plugs last,I've heard they dont last long?thanks mark

 

[Mike Gaines]

THANKS FOR ALL THE RESPONSE ON PLUGS.

I can now make an informed decision on what I want to run as far as:
1) Brand
2) Type of Plug for that brand
3) Heat Range
4) Gap Setting
5) How often they should be changed

I ended up running AutoLite 3923's gapped at .042. They showed good coloration, etc after 10 runs at test and tune last weekend. They were in the car when I had my personal best of 10.61.

 

[gtxracer]

Mark, Thanks for asking. Actually I don't give them a chance to get bad. I change them every other time I take the car out.

 

[dvw]

Mark, Thanks for asking. Actually I don't give them a chance to get bad. I change them every other time I take the car out.

Why?

 

[ozymaxwedge]

Why?

Yes Why ? I stopped doing that a long time ago, waste of cash. A friend of mine with a 10 second small block car has over ten years on his plugs.