Results 1 to 7 of 7

Thread: High RPM Spark Breakdown

  1. #1
    Join Date
    Sep 2018
    Posts
    3

    Default High RPM Spark Breakdown

    I have a general question to ask in regard to spark plug gap. Would a low compression engine, say 8.5:1, require a smaller plug gap that a higher compression engine if using the same coils and ignition, etc.? I have a low compression engine and I notice what I think is a ignition breakdown at redline, 6000 RPM, where engine is missing slightly.

    I installed the MSD Blaster Coils 8207 and thought I could run a larger gapped platinum plug with the hotter coil than what was in the car originally. The original coils are Bosch, approximately 10K Volts, and the manufacture's recommended gap is only .028". The NGK plugs came with a .039" gap, which may be too much for this low compression engine. I will reduce the gap to .035" an see if that helps. Thanks, JDP

  2. #2
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,591

    Default

    What engine and what carburetor?
    Regards, Gary

  3. #3
    Join Date
    Sep 2018
    Posts
    3

    Default

    I'm running a BMW 5.0 V12 with stock fuel injection, ECU, etc.

  4. #4
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,591

    Default

    What's wrong with the Bosch coils? 10K volts, where's that info come from?
    Regards, Gary

  5. #5

    Default

    low compression were your at should be anywhere from .34 to .45 when the compression is higher the gap needs to be smaller. then when you go to power adders( Nitrous, turbo, super charger, race fuel) the gap will change
    shake-n-bake

  6. #6
    Join Date
    Jan 2010
    Location
    Brisbane, Australia
    Posts
    1,591

    Default

    Quote Originally Posted by msdtech50 View Post
    low compression were your at should be anywhere from .34 to .45 when the compression is higher the gap needs to be smaller. then when you go to power adders( Nitrous, turbo, super charger, race fuel) the gap will change
    Perhaps gaps of .034 to .045 would be more correct.
    Regards, Gary

  7. #7

    Default

    yes so if you want you can start at .40 and run it for about a week then check the plugs and go from there
    shake-n-bake

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
About us
Holley has been the undisputed leader in fuel systems for over 100 years. Holley carburetors have powered every NASCAR® Sprint® Cup team and nearly every NHRA® Pro–Stock champion for four decades. Now, Holley EFI is dominating the performance world as well as our products for GM's LS engine. Holley's products also include performance fuel pumps, intake manifolds & engine dress–up products for street performance, race and marine applications. As a single solution, or partnered with products from other Holley companies - Hooker Headers, Flowtech Headers, NOS Nitrous, Weiand, Earl's Performance Plumbing, or Diablosport - Holley products can give you the edge you need over the competition.
Join us