Hot Rod Forum : Hotrodders Bulletin Board - View Single Post - My spark plug colors, am I good or not?
View Single Post
  #15 (permalink)  
Old 05-09-2009, 01:44 PM
cobalt327's Avatar
cobalt327 cobalt327 is offline
WFO
 
Last wiki edit: Intake manifold
Last journal entry: 1980 Malibu Wagon
Last photo:
Join Date: Mar 2009
Location: Atlanta
Age: 60
Posts: 5,037
Wiki Edits: 1616

Thanks: 128
Thanked 598 Times in 547 Posts
Quote:
Originally Posted by bubbahotep
The engine shakes so much at idle its hard to get an accurate fuel flow out of the side holes. Ive got all of 12hg vac from the idle screws which according to Holley is the way to check for proper setting (highest vac)
Hot kick-back can be from a lot of initial timing or even a battery with less than good condition or charge.

As for the engine shaking badly @ idle- are we to gather from this that you have a radical cam?

If that's the case, the plugs will look much as what you've shown until you are actually loading the motor and using it at the RPM that the cam's designed for.

Below that speed, and especially @ idle, a big-A cam will wreak havoc on plug reading- they'll soot up and generally be all but unreadable.

I'd suggest you sort the tuning as best you can (like you've already done, for that matter) AFA total timing and safe jetting goes, then go put some miles on the engine.

If you do this ending w/a "plug chop", you will get a much better indication of the tune from your plugs.
Reply With Quote