Originally Posted by bboy
I've got a theory for you, mind you it's really out there.
Putting in a colder plug transferred more heat to the heads (valves in particular), the heated valves expanded more (lengthened) and closed the lash of the bucket-camshaft interface. Tighter lash meant quieter buckets and less false knock.
Please attack at will.
That's definitely thinking outside the box. Unfortunately, I have no opinion unless I have an idea how EGT and fuel were affected
. When I've used a colder plug in the past in search of the tuning sweet spot, I had to make global changes to my fuel.
BTW, if the engine is 9:1 (and I'd believe Quirt), you're not only igniting a more efficient charge, it will run leaner than the same map on a 8:1 engine, and consequently make more noise.And power.
What is the PN on your coilpacks?