Don Terrill’s Speed-Talk

Anyone have a spark plug recommendation for a small block chevy that is the shorty style. The car has AC delco cr43ts in it now and I am looking for something with more clearance for the headers
Thanks Mitch

a lot of lawn mower plugs are shorter the regular plugs

Acell used to sell a line of header friendly plugs but I can't remember any specific numbers.

I wound up using NGK 5673-7
thanks Mitch

FYI
https://www.holley.com/brands/accel/pro ... ark_plugs/
And it's Accel, not Acell. Just sayin.

I've used NGK and Bosch "ISO" style plugs to clear header tubes on several engines. Here's a comparison to a standard plug:

The autolite AR13x and AR13 series are just as short as the Accel "shorty" plugs, too. For whatever reason, they only seem to have AR13, which is a cold projected tip, or AR13x, which are various heat ranges of non projected tip.

You know, I always ASSumed that shorty plugs had shorter insulators, leading (all else equal) to increased chance of spark tracking, but for this pair, the shorty has a slightly longer insulator! Why can't all common plugs be similarly shrunk? (I bet F1 plugs look like model aircraft glow plugs)

MadBill wrote:You know, I always ASSumed that shorty plugs had shorter insulators, leading (all else equal) to increased chance of spark tracking, but for this pair, the shorty has a slightly longer insulator! Why can't all common plugs be similarly shrunk? (I bet F1 plugs look like model aircraft glow plugs)

Dialectric grease greatly reduces spark tracking.