spark plug observation...

I lowered my plug heat rang by 2 lower.
first thing I noticed was 100 RPM more at Idle.
next thing...smoother idle.
will road test tomorrow and see if any difference there.

...

 

Doesn't really make any sense. Probably running better due to the plugs being new. Hotter plugs run cleaner, but are more prone to detonation.

 

some suggest one heat range lower for every 75-100 HP gain.

 

I'm yet to see a fuel inj engine that changing plugs made a difference in idle speed(at least a factory computer controlled fuelie)... It's common for carbureted engines to increase slightly... Basically new plugs has a effect of increasing timing slightly, they fire more quickly...

 

But I've never had a problem, and that's with 9.5 compression and iron heads.

 

the plugs I removed had about 8K miles.
...... it today and it seemed to have a better cranking attitude...LOL
didn't have any performance gain/loss that I could tell.

 

This is in your LS, right? Maybe it just likes a colder plug. Give it what it likes.

 

It being an LS I have to ask. Were the old plugs oil coated?

 

nope...they were clean. I was chasing a detonation situation. when I stepped into it on a hill , just before it dropped out of OD it would rattle 3-4 times. tried it on a couple of hills this morning and it just pulled on up in OD, didn't even drop back...