Spark Plug Read

[RRoller123]

Does this plug look like it is running a little too hot to you folks? Some brown deposits on insulator, at the location under the arm. A few hundred miles on the plugs, maybe 500.

[klweimer]

Maybe a tad, but it looks pretty good to me.

[AriK]

Too hot is indicative of pinging upon acceleration. No pinging, I wouldn't be concerned.
Did you change to a cooler plug, if so, don't go more than one level cooler.

[RRoller123]

Thanks for the responses. No pinging, car runs most excellently. Using NGK cross from the Champion RN9Y. Will just keep on course I think. Maybe 1 step cooler next change.

[AriK]

Cooler will increase deposits, not sure if that's the correct thing to do. If your compression is up to par i would leave to stock specs.

[AriK]

Double post

[TStark]

Looks just right

No glazing, no grey

Not surprised to hear it runs excellently

If not for the spot, Looks like its out of a modern fuel injected engine.

Friend don't let friends run champions, so thats good

RN9Y is a 6 series ngk which run on the hot side and can induce preignition as mixtures get optimal.
So, that said, i think you wouldn't be off to go to a 7 for a little margin.

[RRoller123]

Thanks all, been away camping in Truro near the outer tip of Cape Cod and haven't had internet to answer these posts.

The plugs are in fact NGK6 series, and out of an FI car, yes. I pulled all 4 and they all look the same, compression runs around 150 give or take a little in all cylinders.

I don't have the car with me now to get the exact NGK number, but I chose the style that has the integral connection tip for the spark plug wire snap on, versus the threaded on tip type. (Don't know what the correct terminology is). But the spin on type, no matter how tightly I attach them, always seem to come loose. So far so good with these.

Pete