dirty spark plugs

[Kevin Brooks]

I recently removed my spark plugs from my '66 327/350hp. I expected to find my plugs carbonized, wet, or oily but not soot covered - as I did. An associate of mine recommended that I change/check the valve stem oil seals. Does anyone think this my be a good course of corrective action. A bit of background - I had often needed to pump the pedal 4x-6x before ignition caught, tired of this I pulled all the plugs, noticed the condition, thoroughly cleaned and replaced and much to my delight within 1.5 - 2x pumps my hard (cold) starting was gone. I'd like not to have to pull the heads but can imagine that if the plugs were this sooty then the space around it couldn't have been much cleaner.
Suggestions/Comments welcomed.

As an aside, when I cleaned off all the grease and crud from my valve covers I discovered the "seam" through the 'o' of Corvette. My car's build date indicates ~ Nov. '65, doesn't seem to me that these valve covers are "correct."

[Duke W.]

Re: dirty spark plugs

If the spark plugs are not the proper heat range for your type of driving they can foul. So, what is the plug manufacturer and number and what type of driving do you do. Primarily city? Short trips? A combination of city and freeway/highway? What is the typical trip length?

Oil seal condition is indicated primarily by oil consumption. So, what is your rate of oil consumption?

Duke

[Jeffrey S.]

Re: dirty spark plugs

Kevin:
Black, sooty deposits on the plug I belive generally indicates an overly rich mixture. Duke's suggestion to go to the next hotter plug is right on but also check mixture at carb.
Jeff

[Kevin Brooks]

Re: dirty spark plugs

My shop manuals call for AC Delco R-44 (original type). However, these are not available and the replacement is AC Delco R-43, which is what was is currently installed. I have seen AC R-45TS for the L-79 engine, which is what I have. The literature seems to suggest either type. Which one is correct?

I have not noticed much oil consumption. But then again my mileage has been very low the last several years, i.e.

[Mike McKown]

Re: dirty spark plugs

The 44's are too cold. The 43's are way too cold for normal driving. Recommend R45S or equivilent in Champion or Motorcraft.

[Mike McKown]

Re: dirty spark plugs

I think the "T" stands for tapered seat, instead of the copper washer which you need for '66 heads. Tapered seats did not come out until, I think, '71.

[Kevin Brooks]

Re: dirty spark plugs

Thanks, Mike.
Based on all that I've heard and read I kinda leanin' in that direction, too. That is, my plugs are a bit too cold. In a few weeks I should have some new plugs and some driving in to see if the changeover makes any difference. I'll post my results then.
Thanks again.