[RBOMAR]

Could someone tell me how long a new set of plugs should be run before getting a reading on them? I replaced mine one month ago and they all still look as white as they did right out of the box. The car runs fine, and has a Holley 650 DP with stock jetting. I beleive 68 in front and 72 in rear, I think! Could it be too lean?

 

[Wes Colby]

You are definitely running lean. The white porcelein should be a medium chocolate color by now. It does not take that long to get a good reading on the plug. Start jetting up by numbers of 2 until you get the right plug reading.

Remember to read your plug JUST AFTER you make a brief WOT speed run...ie. run up to 4,500 - 5,000 rpm's in first gear and then shift. Next, shut off the car, coast down and pull over. Then read one of the plugs.
Just guessing, but you will likely wind up with something like a 72 primary and 74 secondary. Your car will definitely pull harder on top end once you find 'the zone'.
Have fun!

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1970 Malibu - 383 'Fog Fed' Stroker. Houston, Texas...Gold Member #39
Keep America Beautiful - Drive A Brute Force Chevelle!

[This message has been edited by Wes Colby (edited 01-27-2000).]

 

[steve stanbach]

There should be a small brown ring around the base of the porcelain about half a millimeter up. It's pretty hard to see and thats why nascar guys use those doctors' lights with the magnifying glass on it.