Thread: 71 corvette fouling plugs

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I have a 1971 Corvette with a 350 that I had rebuilt in 1988, but it oly has 1,000 miles on it. I had it in storage all of these years. Anyway, when I got it out I gave it a tune up and drove it for 50 or so miles and it began running rough. I checked the plugs and they were wet and black. I proceeded to changed the Carb to a newEdelbrock 600 CFM, change the plugs, and tune the car again. I had the car running great, however after 50 mi. it started running rough. I took out a plug and the plug was begining to foul. One side of the plug was black and the other was white. I can only figure it is oil, but I can't figure out from where. I figure it could be bad rings, but on all cylinders??? In addition it pulls great with new plugs. My latest guess is that it is either a bad manifold gasket(s) or low spark or both. Any thoughts??

Thanks,

Bryce

I think that your valve seals have dried up due to sitting, allowing oil to get by them and fouling the plugs.................

HMM.. that isn't what I wanted to hear. Anyting I can do short of pulling the heads and doing a valve job?

I would run it easy for about two weeks & let the rings re-seat, the seals swell before I started tearing it down again.

should I consider any additives? There are pleanty out there that say they can help old seals and worn rings. I always figured they were bogus, but faced with a teardown I am willing to try. Has anyone seen any results with additives?

Any other ideas on the cause of the problem or is it just the valve seals? Here is some more info on the engine.

350 rebuilt in 1988 1000 miles
Burns oil (Fouls plugs)
After 50 miles the plugs are black on one side and white on the other.
Performer Manifold
Edelbrock carb
EGR valve is disconnected from Carb.

it's only got 1000 miles on it & it sat for how long?

Yep 1,000 miles and it has been in storage for the good part of 15 years! No excuses, I know I have committed a crime, and it seems like I am now paying the price to the corvette gods.

Any advice?

Originally posted by Streets
Bardahl Top Oil or a can of Mystery oi!!!l

Good information by Streets...(As always)--- Worked for my 327/350 hp.. idle for 10 or more years.

Additionally.. as in a posting by Techinspector1--Run the bejesus out of it

Good Luck

Originally posted by poncho62
I think that your valve seals have dried up due to sitting, allowing oil to get by them and fouling the plugs.................

If theres THAT much oil coming from the top I'd target the guides, seals are'nt much more than a mechanics pacifier anyway

Dude- your rings are stuck from the long wait, pour in the Marvel Mystery Oil & let it set for a week, then fire it up & take it on a long road trip, say 500 miles and most of your troubles will go away.