I would at least remove those umbrella seals and install the positive valve seals on the intake valves.
Viton Positive Valve Seals 11 32" x 500" Set of 16 SBC BBC SBF | eBay.

You might be sucking oil into the #1 intake runner from the valley.

 

Thanks for the direction to go.

 

What coolant temps? The front cylinders run cold compared to the others as this is where the pump discharge hits first. If your running a cold thermostat or none at all the leading cylinders have a hard time getting warm enough fo keep the plugs clean.

If this is a Chevy V8 with a flat tappet cam I'd also recommend visually checking the lift at the valve as a fouled plug is one of the early indicators of the lobe and lifter failing. Not that this doesn't happen to other brands or to roller cams as well but the SBC is well known for this.

Bogie

 

Reply to Bogie

Thanks for the reply. Another engine builder installed an Edelbrock mild cam and I am assuming it is a Performer. Probably do not have over 3000 miles since that was installed.
Note that all the other cylinders do not show any "oil fouling" at all. Could it still be the lifters/cam lobe wear on one cylinder only. am planning to pull the intake and redo the gasketing / sealing on it this coming weekend. Can look at lifters then and will have a professional mechanic working with me.

Again thanks,
Jim

 

coolant temps

by gauge it runs 200-210. Runs about 220 after plug fouls out. Hot days 90+ degrees outside. When I check it with laser after shutting down, coolant temps at return hose on manifold are around 180 or so. Check head temps and they are not that high. I suspect the head temp between the siamese cylinders 5/7 shows a little higher.

 

could be the intake gasket leaking, sucking oil in form the lifter valley. but usually you have run on if it is.

 

Run on

Yep I have run on so I shut it down in gear. Thanks

 

Thanks, fixed my problem

Replaced intake gasket and found a flaw in old gasket. Now running great, no run on, no fouling as yet on #1. Thanks for the help. You guys were spot on.

 

thank you for coming back & telling us what the outcome was..so many don't & it's kind of frustrating [to me at least]
dave

 

I agree with that. Thanks for posting back.:thumbup: