Advice on changing the spark plugs in my 330 GTC

I believe the OEM plugs for that car were Champion N7Y. For the life of me, I cannot figure out why.

The ideal plug is an NGK BP7ES or BP6ES.

Use a good anti-sieze compound.

I gap them at .030 (Manual calls for .025)

To start the plugs, just slip a short length of fuel hose over the insulator and insert by hand. When they bottom out, pull the hose off and torque to 15 to 18 LBf-Ft.

Bob Z.

 

I recall N6Y on the plugs

 

Bob Z has it right about plugs. The NGK BP6ES is the correct spark plug for your 330 GTC. If you want to go a bit cooler the BP7ES is the next step. NGK temp range gets cooler with the higher number....the opposite of Champions. Don't bother with Champions. The foul much more easily and you will be replacing sooner than you should. NGKs have always been my choice for both 330s that I have owned.

If you want to see a more detailed analysis of plug choices do a spark plugs Search in the Dino section. The late John Corbani did a very thorough comparison of various plugs.

 

And pull the wires off one plug at a time so you can keep them connected correctly.

 

use a good antiseize compound but not a lot of antiseize near the electrode. it can divert the spark away from the electrode. less is better.
ed

 

I agree 100% with Edward.
Whenever I remove plugs from a car, I do the following:
1) Sand blast them to where the center insulator is pure white.
2) Wash them in laquer thinner.
3) Clean around the center insulator with a pin.
4) Wire brush the threads.
5) Give them a really intense blasting with compressed air, especially the threads.
6) Set the gap.
7) Put a very thin coat of anti-seize on the threads except for the last two near the electrode.
8) Reinstall as described earlier.

[If they're new, just do steps 6, 7 & 8]

I've used this method on every car I've owned since 1974 - it works.

Bob Z.

 

Never heard of doing steps 1 or 2. What's the logic for them? Interesting.

 

Hi, Alberto.
Normally, when plugs are removed, there are various deposits baked onto the internal areas - mostly lead and oil fouling. The sand blasting (or glass beading) removes most, if not all, of these deposits.
The solvent will soften any wet oil deposits missed by the blasting. It will also remove any residual anti-seize or grease on the threads. I usually let them soak in the solvent for a few hours.
Digging around inside with a pin will remove a surprising large amount of carbon that has found its way into the plug's innards.
You can also soak them before blasting - seems to work the same.

Bob Z.

 

These plugs are two bux each...
Why waste all this effort, and subject the ceramic to physical shock.potential cracking to save two bux?
I think this is nutz...FWIW...
To each his own...

 

Doesn't sand(bead) blasting plugs alter the heat range? Or this this bogus folk lore.

TomB

 

+1 on the NGK's

 

These plugs are two bux each...
Why waste all this effort, and subject the ceramic to physical shock.potential cracking to save two bux?
I think this is nutz...FWIW...
To each his own...

Nutz? You didn't even spell it right. Same with bux.
I have probably done well over 1000 plugs this way and have NEVER damaged one.
We're talking about blasting the plugs with a fine abrasive or glass beads, not BOULDERS.
If it was really a bad as you assume, do you think that the FAA would permit aircraft plugs to be blasted? There are even commercial machines to accomplish this.
If there was a risk, I would not do it.
Two bucks on not, I'm not going to toss out twelve plugs every time I remove them. And with my GTC, they are out quite often for cleaning.
Read up on the subject before criticizing someone's work.

Bob Z.

 

I've been blasting plugs to clean them up for 40 years. I'm not sure how much plugs were when I started but waste disturbs my psyche.