spark plug gap

Discussion in 'Street/strip 400/430/455' started by RIVBUILDER, Oct 3, 2003.

  1. RIVBUILDER

    RIVBUILDER Well-Known Member

    what's the best plug gap for a 455?
     
    RIVBUILDER, Oct 3, 2003
    #1
  2. 462CID

    462CID Buick newbie since '89

    I've always used 0.040", but I hear a lot of guys run 0.035" with good results.
     
    462CID, Oct 3, 2003
    #2
  3. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Tim,
    Gotta give us more information. That's too general a question. Compression ratio?, Ignition system? Carburetor?
     
    LARRY70GS, Oct 3, 2003
    #3
  4. RIVBUILDER

    RIVBUILDER Well-Known Member

    10.5:1 comp. ,stock dist. w/unilite conversion, 800cfm quadrajet.
     
    RIVBUILDER, Oct 3, 2003
    #4
  5. LARRY70GS

    LARRY70GS a.k.a. "THE WIZARD" Staff Member

    Tim,
    I would stick with .035. If you want to experiment, increase the gap .005 at a time until performance falls off. I think .035 is gonna be your gap though.
     
    LARRY70GS, Oct 3, 2003
    #5
  6. IgnitionMan

    IgnitionMan Guest

    .035 max, as the Unilite doesn't have drivers for larger gaps.
     
    IgnitionMan, Oct 3, 2003
    #6
  7. 68 LeSabre 4dr

    68 LeSabre 4dr Well-Known Member

    Tim sounds like 35 is the winning # !

    Set them ay 25 ! See ya at the strip !!!!!!!!:moonu: :moonu:
     
    68 LeSabre 4dr, Oct 4, 2003
    #7
  8. 70lark

    70lark Well-Known Member

    I set mine at .045 wit HEI. Is that too much? They came out of the box at .060:Brow:
     
    70lark, Oct 4, 2003
    #8
  9. IgnitionMan

    IgnitionMan Guest

    Under 10.50:1 c/r,

    Unilite, NO matter the coil used, .035 max

    HEI, NO matter the coil used, .045 max

    Higher comp ratios, drop the gap at least .005 or if the top end rpm has a miss you cannot find in the system, like wires, etc.
     
    IgnitionMan, Oct 4, 2003
    #9
  10. BadBrad

    BadBrad Got 4-speed?

    I hate to ask this of the IgnitionMan since I'm using Pertronix, but hey at least I'm also using an MSD 6A and an Accel coil. Still 0.045 with the old 9.7CR IgnitionMan?
     
    BadBrad, Oct 4, 2003
    #10
  11. IgnitionMan

    IgnitionMan Guest

    Yup. .045 max.

    Precident is, MSD box dictates the gap, even though the PerWhat is a full ignition system. In your case the PerSputter is only making a reference signal for the MSD to use.

    NO MSD, PeerMiss would dicatge the plug gap.

    Only variablefor BOTH systems is, higher or lower comp ratios.

    You are aware there is a dedicated MSD pickup conversion for the stock points dists, available when the PerStopped fails, aren't you!
     
    IgnitionMan, Oct 5, 2003
    #11

Share This Page