Grounding question

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DesertRat

DesertRat

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I forgot where the negative battery cable terminates on my 1967 Barracuda. I am also interested in input on where the engine block ground cable terminates. I am building a custom ground cable that will have a 12GA whip that ties into my grounding bar system where I am running all the grounds on the car to. Appreciate some input please.
TIA,----------DR---------:coffee2:
 
The neg cable on my 68 is bolted to the front of the left cylinder head just below the valve cover.
 
Creedmoor got it on the battery ground cable.

You may want to run a ground strap from engine to chassis. If you ground everything to the stud in your engine compartment, a 12ga wire may not be large enough. I'd consider using the chassis to ground items not close to your compartment ground stud.

Use the ground stud for headlights, EFI or other electronics in the compartment.

Good idea vs bolting them all up to the radiator support.
 
crackedback said:
Creedmoor got it on the battery ground cable.

You may want to run a ground strap from engine to chassis If you ground everything to the stud in your engine compartment, a 12ga wire may not be large enough. I'd consider using the chassis to ground items not close to your compartment ground stud.

Use the ground stud for headlights, EFI or other electronics in the compartment.

Good idea vs bolting them all up to the radiator support.
Click to expand...

I am planning all parallel grounding.I will install the main negative cable to the engine head and run a #10 from a different place on the engine to the chassis (read body, perhaps MC bolt). I have two multiple terminal grounding bars installed, one in the steering column support steel under the dash and one above the battery behind the core support. All supplemental grounding is being run to these grounding bars which are tied together also with a #14 ground wire. My plan is to run a single cable from the battery negative to my battery shutoff switch. From the closed circuit side of the kill switch I will build a custom cable that runs to the left engine head with a #10 parallel conductor running to my grounding bar in the engine bay. I am trying to avoid grounding ghosts in the machine as the entire car has about 4 coats of epoxy paint on everything. Thanks for responding---------DR-----------O:)
 
There should also be a smaller ground wire from the battery terminal to the front radiator support...
 
some say don't use the ground to the rad if it's aluminum to avoid electrolysis...
me,i don't know.
 
^^^ I think the rad support was mentioned, not the rad. But, indeed, an AL rad is best not grounded to lower electrolytic action. Notice that production AL rads use plastic tanks and plastic/rubber supports; the AL rad doesn't touch the chassis.

Just another reason to keep one's coolant regularly changed out: keep the anti-corrosion additives fresh to give any hard mounted AL rad as much help as possible.

The multiple epoxy paint coats is a good reason for the extra grounding setup; an interesting problem.
 
This is NOT correct. The OPPOSITE is true. You want the BATTERY, the BODY, and the ENGINE all as close to each other as possible. One good way is to get a "starter" (ring to ring) cable in say, no4 or larger, bolt to the rear of the driver side head, and then to a bolt through the body or to one of the master cylinder mounts.

Electrolysis is caused by chemical action IN the coolant, caused by the coolant itself and the materials in the engine and radiator itself. In other words the material in the engine and radiator, together with what is in the coolant, turns it all into a battery. I "ain't" an expert on this, but there are various coolant additives to modify the coolant and prevent same. Over the road trucks use this stuff.
 
nm9stheham said:
^^^ I think the rad support was mentioned, not the rad. But, indeed, an AL rad is best not grounded to lower electrolytic action. Notice that production AL rads use plastic tanks and plastic/rubber supports; the AL rad doesn't touch the chassis.

Just another reason to keep one's coolant regularly changed out: keep the anti-corrosion additives fresh to give any hard mounted AL rad as much help as possible.

The multiple epoxy paint coats is a good reason for the extra grounding setup; an interesting problem.
Click to expand...

I am having my orginal radiator done with a new copper 3 row core. (for no small amount of treasure) I thought about aluminum a bit but just couldn't bring myself to do it. The gurus here seem to think that copper & brass to a better job and I really liked all the cool stock numbers on the top of my stock tank. The .040 overbore was a heavy consideration as well. I do know that there is no such thing as too much grounding on an automotive electrical system and I am operating on that premis. See color edits in post #4, may clarify.
Thanks to all who chimed in-------------------DR--------:coffee2:
 
i think a test for electrolysis is battery terminal to rad coolant.
.1 volt or more may indicate some current flow.
 
OK, with the copper/brass rad, then the corrosion moves away from the rad and goes to the block & heads. In any electrolysis situation, one material is 'sacrificial', depending on where it falls on something called the galvanic scale. With brass & iron, it is the iron. With AL & iron, it is the AL. So your brass rad is safer from corrosion long term. Again, good, regular changeout of the coolant will keep the corrosion under control.
 
I use a sacrificial anode in my radiator. I got it at a boat store. It replaces the petcock. Before I did this, my chrome water neck corroded right through the side.
 
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