Inliners International Forums General Discussion Engines fuel distribution

first i have a 250 w/ a holley 390 carb, langdon's dual exhaust to 2" pipes, offenhauser intake is heater w/ water. ok

while doin a little tune up and oil change today i noticed the the middle two plugs were black, outside of them were white, and the front and back plug were brown, i'm assuming this is from the fuel (holley 390 carburator) going more to the middle cylinders

but my questions are 1. is this a major problem, will it affect performance and 2. what could i do to improve.

Normal for a offey with out the runner ribs in the bottom of the intake. Some Older Offeys Had a ribs running to both ends which In fact worked a little to well and Leaned out the center two cyl. to help with that issue a few were ground down. Now in your case You may want to try useing a plug a degree or Two Hotter On the center to cyl.

thanks twisted,will that do anything to improve performance, or actually is this hurting my performance right now?

I ran a single 4 bbl , Clifford intake, on a 261 Chevy and now a single 4 bbl,Patrick's intake, on a 302 GMC.No variation in plug color at all.

Some say it was a Very small gain in performance to vary the plug ranges(ex 1,6 had the same 2,5 had the same & 3,4 had the same ) Being 3 different heat ranges due to how the fuel was being distributed to those cyl. There could? be some other issue at play here But with out seeing the Plugs or hearing the motor. Carb could be in need of tuning(floats air fuel mix etc), timing ajusted how and where the PVC is setup,a small vacum leak ? I personaly never had that issue on my Offey (600 holley). I never ran a single 4bbl cifford Only my dual(450s) and My own 3x4 tunnle ram.(again 450s)