How Does This Spark Plug Look To You??

[CudaChick1968]

Just a tip.

The inside back cover of every old Chilton's manual has a great Spark Plug Diagnosis Chart. (New ones may too but I haven't bought one in years.)

 

[beanhead]

I’m not 100% sure but I think the factory recommends an initial timing of 7 to 12? Would he be a little higher if he’s at 15?

It's the modern-day fuel formulations that have thrown everything off....and depending on the year/package the factory spec was as low as zero. Crazy! When the timing is right the ground strap will discolor into the bend. The new pump gas just doesn't burn the same.

 

[JG71B]

Stock jetting sure can be too rich for a given combe; the engine will want it wants for the conditions, fuel quality, etc. As far as the timing read on the NGKs, there isn't much of a defined mark as there was with those first plugs, at least to my eyes and screen anyway? "If it was me" I'd put in a couple of new plugs and bump the initial to 18 and drive it (without stomping it hard) and see how it feels. Give it some miles and then take a look at the new plugs, if you like the burn mark and the throttle response, then go from there. Of course....this is kind of "going down the wormhole" of tuning but you should IMO always get the timing squared away before getting into the carb.

I bumped the initial up to 18* my dial timing light. Strap looks OK to me now I think compared to the first pic. Then went to #7 on the Edelbrock tuning chart which is about 1 1/2 stages leaner jets with .073x.047 rods. I went 1 step leaner on the secondaries also while there. This is where it's at now. Response seems crisp. Drives good. Pulls good and no audible pinging. I'll drive it for a few days and check again. Maybe throw some fresh plugs in then also

 

[JG71B]

Eddy carbs are calibrated @ sea level and are usually Fat from the factory. Get the ignition squared away like Beanhead said then start messing with the carb. I would get the Calibration kit and start leaning it out in small steps. A 0.98 primary jet is fairly fat, follow the Ed chart. The first lean step #6 is just a rod change= easy.

Timing at 18* and went to #7 on the chart. That's about 1 1/2 steps leaner with the .073x.047 rods. I briefly went to .075x.047 rods and it was slightly hesitant off idle and slightly surging at cruise so the .073's went back in.

 

[wagonman]

Timing at 18* and went to #7 on the chart. That's about 1 1/2 steps leaner with the .073x.047 rods. I briefly went to .075x.047 rods and it was slightly hesitant off idle and slightly surging at cruise so the .073's went back in.

Sorry I had a little senior moment going on Yes 7 is good. Plug looks way better, mileage should increase also. What is your altitude?

 

[JG71B]

Sorry I had a little senior moment going on Yes 7 is good. Plug looks way better, mileage should increase also. What is your altitude?

650'

 

[wagonman]

Nothing to fret about. 4300 here takes a little messing with but I run Holley's. The Dual Quad 383 63 Belvedere wagon W/ 1405s has been a learning experience. Tuned for My 4300 but going to Nevada @ 2200. We shall see.

 

[JG71B]

The Bosch plugs seem to run cleaner. Going to leave them in for now. I don't know if it's me but, it seems to idle smoother with the Boschs' also. Still no pinging at 18 initial. Taking the usual routes I should've had to stop for gas by now. Almost but not quite. Still cant believe it wanted fed leaner than otb.

 

[HEMI-ITIS]

Plug still looks a little hot with alot of timing as well.

 

[Bee1971]

You mentioned 34 or so TOTAL

Did you verify that after you bumped it up to 18 initial

And ported or full vacuum advance with your distributor

 

[JG71B]

You mentioned 34 or so TOTAL

Did you verify that after you bumped it up to 18 initial

And ported or full vacuum advance with your distributor

Honestly Im going to have to verify that. I did NOT check that. I think I got complacent not hearing any pinging under load bumping up to 18 and didnt even think about it. Thanks for reminding me!