Grounding questions.

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Kent mosby

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I understand that we need to ground the battery to the engine block. On an RB block, where do you do that? I have a nice spot on the trick flow aluminum intakes but with gaskets etc., is that a good spot?

The second dilemma is, if the motor is installed on rubber pads, the it is electrically isolated from the frame. Shouldn't we also ground the block to the frame? If so , where. I keep reading that you can never have enough good grounding.

Thanks for any help.

Pictures help me understand location easier.
 
Typically on these old girls there is one ground from battery negative to core support, one from battery negative to driver side head and one from passenger side head to firewall.

The reason for grounding is to ground where electrical impulses are happening, which is mostly in the heads (think spark plugs). Grounding to the firewall covers the cabin, grounding to core support is because of lights. Block would be grounded through the head bolts.

That's my theory anyway. I'm sure if my theory is wrong, someone will correct me, lol.
 
I run the battery negative to the intake manifold, a ground strap from my electronic ignition box to the intake and an additional ground strap from the intake to one of the brake master cylinder mtg studs. Never had a ground issue. 65'
 
It is very important to have a ground strap from the engine to the body. This gets left off on a lot of engine swaps. A lot of weird electrical issues can be traced to this.
 
I like to use a BIG ground from the engine to the body in addition to "whatever was there." Notice the alternator mounting hole(s) on the front of the pass side head. This same hole(s) are on the rear of the driver side head. Use a short "starter" cable (eyelet to eyelet) maybe a foot long, and bolt to the firewall, or to the master cylinder mounting bolt

Grounding strategy gets a LOT more complicated the more electronics you have, especially EFI, O2 sensors, ANY modern systems using sensors, solid state, etc.

Part of the reason is noise pickup IE ......EMI --electromagnetic interference-- a great example of that is high output ignition such as MSD. There has been cases where the high power pulses in the plug wires is induced back into the pickup/ trigger circuit ad re-trigger the MSD.

Another is what is called 'ground loops' This is where current in a circuit or ground circuit causes a voltage differenc which then affects related or connected circuits. The infamous "up and down" pulsing of a voltage regulator is just one example. These can be difficult to run down.
 
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You are going to want a clean ground for your FI system. Ground noise can cause issues there.

Battery up front, ground using a good size cable to block if possible. The trans could use one as well... the starter bolts up there and NOT to the block. ever seen a fried/cooked speedo cable? Guess what caused that.

When the engine is painted, make sure the trans mating surface is clean, no paint.
 
67Dart273 said:
I like to use a BIG ground from the engine to the body in addition to "whatever was there." Notice the alternator mounting hole(s) on the front of the pass side head. This same hole(s) are on the rear of the driver side head. Use a short "starter" cable (eyelet to eyelet) maybe a foot long, and bolt to the firewall, or to the master cylinder mounting bolt

Grounding strategy gets a LOT more complicated the more electronics you have, especially EFI, O2 sensors, ANY modern systems using sensors, solid state, etc.

Part of the reason is noise pickup IE ......EMI --electromagnetic interference-- a great example of that is high output ignition such as MSD. There has been cases where the high power pulses in the plug wires is induced back into the pickup/ trigger circuit ad re-trigger the MSD.

Another is what is called 'ground loops' This is where current in a circuit or ground circuit causes a voltage differenc which then affects related or connected circuits. The infamous "up and down" pulsing of a voltage regulator is just one example. These can be difficult to run down.
Click to expand...
Ok, so "rear of the driver side head. Use a short "starter" cable (eyelet to eyelet) maybe a foot long, and bolt to the firewall, or to the master cylinder mounting bolt". Got it. Now where would be the shortest/best place to, also, connect another ground cable from rear of the driver's side head to the frame, or from master cyl mounting bolt to the frame? Thanks ahead.
 
Well there IS NO frame as such. Unless you are talking about say, a pickup. With that you are on your own. Once you have a really good ground to an A body "body" only thing left "loose" are the fenders doors and trunk lid
 
67Dart273 said:
Well there IS NO frame as such. Unless you are talking about say, a pickup. With that you are on your own. Once you have a really good ground to an A body "body" only thing left "loose" are the fenders doors and trunk lid
Click to expand...
OK then, bolt to the firewall, or to the master cylinder mounting bolt should suffice. Thanks again.
 
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