Spark plug questions

[PhillipsLT5]

I am using NGK Iridium TR 71 X, pricey but last plug I probably will buy

[chriskinzel]

I have had one of mine find the road as well. two others where lose at the same time (no wonder it was running so poorly!).

[efnfast]

It makes a hell of a racket when one comes out.

[Jim Nolan]

Could the plugs being loose or coming out the result of some time in the engine's past the plugs being removed when the motor is still hot?

[scottfab]

Originally Posted by Jim Nolan

Could the plugs being loose or coming out the result of some time in the engine's past the plugs being removed when the motor is still hot?

More like put in when hot/warm.

I use anti-seize on just the top two threads
(farthest away from the spark tip).
This ensures none get in too deep.
The idea is to reduce the total max friction
should one plug want to resist coming out
(dissimilar metal bonding)
In 17yrs I've never had a plug come out or even loosen on
the ZR-1. On my 73 BB I did several times.
I torque to 20lb.

[hiperf406]

Well got all my plugs changed & took car for a drive. Before I changed the plugs the car had a significant miss in it - which I attributed to my injectors as am still still running original injectors. On my test run car ran great no miss at all & it seemed to pull stronger. The plugs looked good with a light brown color to them. It took longer to change # 8 than to do all the rest !

lorne #1748

[scottfab]

Originally Posted by hiperf406

...snip...
It took longer to change # 8 than to do all the rest !

lorne #1748

Welcome to the "Knuckle Busting #8" Club =D>

[Racinfan83]

It took longer to change # 8 than to do all the rest !

I actually had more trouble with #7 then I did with #8....

[Paul Workman]

Originally Posted by PhillipsLT5

I am using NGK Iridium TR 71 X, pricey but last plug I probably will buy

I follow Pete's philosophy; replace often, have a fresh set in the motor as much as possible.

A "gee wiz" exotic rare earth plug might last a lot longer, but the insidious half-life degradation is also longer.

On the other hand, the conventional copper core AC/Delco 41-602s can be had for about $2.00 + tax ea. and are good for at least 10k miles. That means my Z will have a fresh set in it for under $20 every season (≈ 3000 miles or so) well above their half-life performance threshold, and perhaps superior to a rare earth plug in it's twilight phase. And, considering how easy it is to replace plugs in an LT5, I don't see any down side to using the conventional plugs.

Your mileage may vary...

[XfireZ51]

I use a standard plug and a bit of oil for anti-seize. I found that using regular anti-seize allows the plug to loosen often. As for the plug, it's a NGK BKR6E.
When you view the ground strap for correct heat range, the 5 is too hot, and the 7 too cold. It's the Goldilocks plug. I also gap to .035". A .050" appears to give you a smoother idle, but puts more of a load on the coils top end.