Please opine on an MSD Street Fire

Discussion in 'Ignitions & starters and electrically related comp' started by DorianL, Aug 14, 2018.

  1. DorianL

    DorianL solid fixture here in the forum Staff Member

    Hi All,

    I am about to pull the trigger on an order for the 1969 Corvette. A buddy and I plan to have a day of tinkering two weekends from now.

    One thing I have learned with this particular car is to: prioritize, prioritize, prioritize. You never know when something important can come up like a rusted out gas tank. It is best to afford things if they has a significant impact. So far the list of things that need attention is long: suspension bushings, rear leaf spring, emergency brake, weather stripping, and more. Best to be careful with limited resources.

    I want this engine running as smoothly as possible. That would go a long way to give me great satisfaction, enjoyment and confidence. If it runs smoothly, I am more likely to take it out for a drive.

    So far we have replaced the cam and lifters, reset the ignition timing, rebuilt the carb and added an electric choke, rewired the engine bay, given full battery to the ignition, reset the throttle linkage geometry.

    We also replaced a torn trans mount and moved the exhaust pipes away from banging on the body.

    Things are much smoother.

    We tested a fuel pressure regulator and that improved things even more. I will be adding one permanently.

    The ignition cables are in at 1,500 ohms per foot. I will be replacing that with a set of 50 ohms per foot + new plugs.

    The distributor, an HEI, looks new and of decent quality.

    My question is this (and we finally get to it) what impact would an MSD Street Fighter Box and matching coil bring? Beyond the new plugs and wires... will it further improve idle and upper RPM? Or will the difference be marginal?

    MTIA !

    D.
     
  2. DorianL

    DorianL solid fixture here in the forum Staff Member

    Hm... maybe I am trying to quantify the un-quantifiable. Would this improve things by say 20-25%. Idle and upper RPM
     
  3. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    the improvement , provided by a multi ignition spark, ignition, will depend on how well your current ignition works vs the new ignition
    , in most cases there will be a minor improvement, and its almost sure to increase dependability,
    and smooth the idle,and allow a couple hundred extra rpm with better power,
    and provide both a minor increase in mileage (frequently in the 1 mpg increase, range)
    your not likely to get a noticeable power increase thats easily felt, like adding an extra 15 hp,
    but over all emissions tends to be reduced, a minor upper rpm power boost and generally the engine runs better.
    most people find its very much worth the time and effort and cash spent.
     
  4. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    With You Living so far away in Belgium Dorian and racing secondary issue on this Corvette what is most important is guaranteed Reliability with Zero Failures.

    MSD Has a terrible reputation.
    I have seen it 1st hand.
    Streets.
    Dragstrips.
    In the Race shop I worked at and on the chassis dyno MSD Components ignition systems failing.

    If Your HEI is working leave it alone.
    If want a premium upgrade use a Davis Unified Ignition, DUI HEI.
    DUI HEI Sold on Summit Racing Parts online.
     
  5. DorianL

    DorianL solid fixture here in the forum Staff Member

    Are you guys disagreeing on this one ?
     
  6. DorianL

    DorianL solid fixture here in the forum Staff Member

    This is kinda where I am leaning...
     
  7. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Yes I am.

    MSD Is Trash Can China
     
  8. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    A while back Grumpy and me agreed Crank Trigger Race is best for many.
    My Vote is Electomotive.
    Expensive.
    Take all of your 2500 bonus money.

    I swear by Vertex magneto.
    Grumpy disagrees.
    But he used on his 1968 Corvette 496 BBC Street Racer back in the day.
     
  9. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    Brians not totally correct,I have near zero desire to run any hei,ignition.
    or similar coil in distributor cap chevy ignition,
    but from a reasonable comparison , based on cost vs performance and durability,
    well you and I are forced to make choices based on both cost and performance.
    Id swap to a vertex magneto in LESS than a 1/2 nano second if I had that option on most BBC and SBC engine builds,
    but finding one in pristine condition ,at a decent price is not very likely.
    crank trigger, individual, coil per cylinder ignitions and computer controlled ignitions have some advantages over the vertex ignitions

    after all that magneto technology is almost 70-100 years old, and the better individual coil per cylinder ignitions that can adjust individual cylinder timing,
    with the computer control speed to detect detonation, and in some models, that,
    work with injection controls and sensor out-puts ,
    too change injector pulse duration, or adjust the advance or retard curve, as required,
    thousands of times per second if that were required are far newer than the magneto ignition.
    I never had any problems running a vertex magneto, and would love to find one , but in many more modern cars the ignition advance curve is computer controlled and a vertex can,t be swapped into the car easily


    related info

    http://garage.grumpysperformance.com/index.php?threads/vertex-ignitions.1320/#post-64168

    http://garage.grumpysperformance.co...il-per-cylinder-application.10741/#post-46899

    http://garage.grumpysperformance.co...ouble-shooting-rebuilding-hei-ignitions.2798/

    http://garage.grumpysperformance.com/index.php?threads/distributorless-ignition.5916/#post-18181

    http://garage.grumpysperformance.co...es-and-trouble-shooting-guide.1179/#post-5875

    http://garage.grumpysperformance.co...ition-wires-getting-the-header-clearance.840/

    http://garage.grumpysperformance.co...ing-a-stand-alone-ignition-coil.275/#post-337

    http://garage.grumpysperformance.com/index.php?threads/shiming-a-distributor.251/

    http://garage.grumpysperformance.co...grated-multi-spark-digital-rev-limiter.13948/

    http://garage.grumpysperformance.co...stributor-for-your-application.855/#post-8931
     
    Last edited: Aug 14, 2018
  10. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    If you read up on MSD the multiple spark discharge quits above 3000 rpms.
    Coil Magnetic flux saturation time is not there and has to go to Single fire spark for high rpms.
    Crank Dwell spark duration time is double with a Magneto like Vertex.
    40 degrees.
    Joules or amperage delivered at the spark plug is much higher with a Magneto.
    Timing accuracy is always dead on.
    No Electronics to heat up and fail.

    I have Factory HEI on my 1987 Tuned port Corvette.
    It works.
     
  11. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    Be surprised how many guys dumped MSD.
    Running Mags Magnetos now.
    Some of the most powerfull Twin Turbocharged cars in the world.
     
  12. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    They are expensive a Nice Vertex Mag.
    Paid over $800 for Pontiac V8 & Olds V8 Vertex mags I have.
    Not for everyone like I stated in the past.
    Just Perfect for me.
     
    Last edited by a moderator: Aug 14, 2018
    Strictly Attitude likes this.
  13. Loves302Chevy

    Loves302Chevy "One test is worth a thousand expert opinions."

    The older (made in USA) MSD units were good.
    Chinese made now = not good anymore.
    If your current HEI ignition system is in top shape, then you cannot expect huge gains from any upgraded system.
     
    Strictly Attitude likes this.

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