I like Autolite sparkplugs - they've proven themselves well over the years in my Fords .....so I'm prone to keep using them. The other day I ran across a box of 124's, they are the next step colder than the 45's and are the standard type of resistor construction. Would they be a good choice for a bit cooler tip than the 45's running in my driver car (which look a little hot to me). The 124's are the coldest resistor type 18mm x .468 reach plug shown on my Autolite heat range chart.

Is anyone already using this plug? and what sort of induction/ignition set-up is on the engine?

 
 Steve Metzger       Tucson, Arizona

Ditto on your comments on the Autolite sparkplugs.

The Autolite 124’s are similar in heat range to the old BTF-1’s.  Very cold so they work well where the compression is increased or the rpms are sustained at the higher levels.  I used the 124’s in Randy Gummelt’s dragster engine and they worked perfect in that application with 7½:1 cr and 16 psi of boost.  Any instance where the compression ratio is 11.0:1 or higher on a normally aspirated Y, then I’ll consider their use in lieu of the more expensive racing spark plugs.  The 124’s do have a very thick ground strap so I cut the end of the strap back in line with the center of the spark plug before installation just to unshroud the spark.  I’m doing the final details for a 12.0:1 Y engine right now and it will have the 124’s by default for the dyno pulls.  Regarding ignition setups, I fall back to the MSD ignitions anytime higher than normal compression ratios and the use of colder spark plugs come into the picture.

Lorena, Texas (South of Waco)

Good info!  Thanks Ted.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias