Focaljet - Ford Focus Forums - View Single Post - whats the point of Colder Heat Range Spark Plug?

**Petik** · 08-30-2006, 11:11 PM

So, the secondary role of spark plugs is to conduct heat from the cylinder into the head (and thus coolant). The "heat" of a spark plug refers to how much heat it conducts away from the cylinder. The colder the spark plug, the more heat it conducts. For stock and slightly modified you most likely want to stay with the stock "heat". For FI and wild cars you'd want to go colder to keep the cylinder temps in check.

08-30-2006, 11:11 PM	#2
Petik TEAM Member Join Date: Jun 2004 Posts: 947	Re: whats the point of Colder Heat Range Spark Plug? So, the secondary role of spark plugs is to conduct heat from the cylinder into the head (and thus coolant). The "heat" of a spark plug refers to how much heat it conducts away from the cylinder. The colder the spark plug, the more heat it conducts. For stock and slightly modified you most likely want to stay with the stock "heat". For FI and wild cars you'd want to go colder to keep the cylinder temps in check. __________________ '02 ZX3, 264whp/251tq @ 12psi, GT28RS custom kit, FC 65mm TB, JE 9:1 pistons, Eagle Rods, FR Head, Crower springs, Comp turbo cams, Esslinger gears, ARP studs/bolts, Focus-Power billet main caps, '00 ported intake mani, Quaife LSD, 4.06 gear, Spec stg3 clutch, Fidanza flywheel, SCT Pro Racer + Raptor tuning, Zeitronix Wideband, J&S Safeguard, FC STS.