Engine ground

Discussion in 'Engine Topic' started by 76 camaro car 1, Feb 22, 2011.

  1. 76 camaro car 1

    76 camaro car 1 Veteran Member

    Apr 23, 2010
    What is the purpose of the engine to firewall ground strap? Everyone I ask has a different reason for its use and noone agrees with what the other one says.
  2. CorkyE

    CorkyE Veteran Member Lifetime Gold Member

    Nov 4, 2004
    Ringgold, GA
    What answer are you looking for?

    The distributor is grounded to engine by a wire, and the engine is grounded to the firewall. Doesn't sound like much but remember there is a paper gasket between the distributor and intake.

    That's just one example I can come up with without a lot of thought.

    If you don't want to run that particular ground, then don't. And BTW, who are you asking; just asking?
  3. COPO

    COPO Veteran Member Lifetime Gold Member

    Sep 15, 1999
    Helps stop radio interference from the distributor. Some even put a capacitor on the alternator.
  4. flowjoe

    flowjoe Moderator Staff Member Lifetime Gold Member

    Feb 7, 2006
    Survey "sez"...Mark has it...:bowtie: ^+1
  5. Twisted_Metal

    Twisted_Metal Moderator Staff Member Lifetime Gold Member

    Feb 26, 2004
    Bloomington, MN
    Because the engine is grounded directly to the battery but nothing else is.
    The only other connecton between the negative post on the battery is a dinky little fusible link running to the fender.
    Disconnect your main ground cable from the engine and that link will cook because it's the only way for every circuit in the car to ground.

    The engine needs an electrically connection to the car body for all of the lights, accessories etc. to function.

    In a factory car....
    The motor mounts are rubber insulated, as is the transmission mount.
    The radiator is rubber mounted so the trans cooler lines won't even make a good ground.
    The exhaust system is hung by rubber straps and the fuel line has a rubber connection too.

    About the only thing left to ground the body to the engine is.... The shifter cable.
    People have actually burned up shifter cables because they had no engine ground strap. :eek:
  6. 70sbudget

    70sbudget Veteran Member

    Mar 21, 2008
    san diego
    so the ground from the bat to the alternator bracket doesnt sufice?
  7. 1972L

    1972L Veteran Member

    Feb 22, 2009
    Miami, Florida
    Since the engine/transmission is rubber mounted for the most part, the lights and accessories need a path back through the engine, back to the battery. Though you may have a ground on the fender for the front lights etc to function, it's a long way back to the tail lights.
  8. GoldenOne7710

    GoldenOne7710 Veteran Member Lifetime Gold Member

    Jun 23, 2004
    Athens, GA
    If in doubt.....use the ground strap and be done with it. Definitely ain't gonna HURT anything.
  9. greencamaro1981

    greencamaro1981 Veteran Member

    Jun 2, 2010
    the batt ground to the engine the ground will get from the motor to the firewall and frame they will either go through the tranny cable or throttle cable or the wire you install
  10. Twisted_Metal

    Twisted_Metal Moderator Staff Member Lifetime Gold Member

    Feb 26, 2004
    Bloomington, MN
    Not for the circuits grounded through the body.

    A bare, braided copper cable bolted to the rear of the passenger head and the firewall works perfectly for this electrical connection and prevents damage to incidental connections like the throttle or shifter cable.

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