Ngkbpr5es. Ever see a plug this grey? 464. Aluminum heads. 11 -1. Sunoco 110 fuel. New plugs. Only ran to check timing
Lead fouling or additive. (similar to the orange from MMT in Octanium booster) The Sunoco your running leaded? But unsure of it happening in short run time.
I was thinking the same. Haven't seen that gray color in decades! Yup, Sunoco 110 is leaded. For a short run time like that I wouldn't worry too much. Running enough to heat up the plugs should take care of it. If still showing same symptoms after some decently hard running, maybe time to look at air/fuel ratio. Devon
Me neither, not since the early 70’s The tailpipe on our 66 Impala wagon would get that color after a long highway trip.
I actually ran the engine quite awhile. It was definitely up to temp but it was mostly idle time. I did try out some different squirters on the Holley just messing around. Guess I never checked the exhaust pipes for residue. Was running ngk 6 and switched to these 5,s. Thanks for the replies.
