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Autolite 3924 Heat Range Chart How to Determine Correct Spark Plug Heat Range

Can I use these Autolite 3923s or do I need to run the 3924s
Can I use these Autolite 3923s or do I need to run the 3924s

a 3924 would be a resistor plug with a heat range of 4 (3 hotter than the 3911 plug). the 1st 2 #'s (39) designate the 5/8 .750 reach plug.

Autolite 3924's or 3923's ? - Club Cobra
Autolite 3924's or 3923's ? - Club Cobra

I've been using Autolite 3924's in my Vic Jr. headed 393. What's the real difference? I know spark plugs have heat ranges but does it really 

Understanding Heat Range
Understanding Heat Range

Working closely with engine manufacturers,. Autolite engineers have developed plugs in many heat ranges to suit all engine applications. They range from COLD 

What heat range sparkplugs should I use?
What heat range sparkplugs should I use?

For example, the Autolite 3924 is a VERY commonly used plug in engines making up to about 600 HP or so, and it's a heat range that most stock engines use.

ASP2009 Autolite Heat Range.qxd
ASP2009 Autolite Heat Range.qxd

Autolite® Spark Plug Heat Range Chart. Tableau des températures des bougies Autolite® 8251/XS3924. 52248302. AP54058308. XP52248302. 2399, 8252/.

Correct Shorty Spark Plug?? | NastyZ28.com
Correct Shorty Spark Plug?? | NastyZ28.com

My engine builder put Autolite AR3924 plugs in and said to get some The '4' on the end of the Autolite part number is the temp range.

Heat Range Conversion Chart - AutoliteSparkPlugs.com
Heat Range Conversion Chart - AutoliteSparkPlugs.com

However, according to an Autolite reference chart, Autolite 86 has the same heat range as 2244 and Autolite 303 is a hotter plug than 2974.

Autolite-3924 (8 Heat Range)
Autolite-3924 (8 Heat Range)

Take a look at our Autolite-3924 (8 Heat Range), as well as other Spark Plugs available for sale here at Fig Speed High Performance Speed & Marine Parts 

Racing Spark Plug Cross Reference Chart - Dragstuff
Racing Spark Plug Cross Reference Chart - Dragstuff

Sparkplug cross reference between Autolite Racing, AC Delco, NGK Heat Ranges - The larger the number after the dash the colder the plug 

How to Determine Correct Spark Plug Heat Range
How to Determine Correct Spark Plug Heat Range

Within the Autolite family, this particular plug is toward the hotter side of the range that runs (cold-to-hot) 3922 – 3923 – 3924 – 3926.