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1968 Camaro SS Clone
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Discussion Starter · #1 ·
Getting ready to tackle some projects I’ve been putting off and one is my grounding situation in the engine bay. I currently have a heavy gauge wire from the wire to the aluminum heads. I am using they ground strap from the other head (header bolt actually) to the firewall that came with the car. IMO, it’s tiny and I going to replace it with something of the same gauge as my battery cables. I don’t have a ground strap from the engine to the subframe and don’t think I need one because nothing is grounded to the subframe. Thoughts on that? Also, should I stick with grounding through the aluminum heads or try to ground to the block? I use anti seize when I put a bolt in aluminum and wonder if that affects the grounding.
 

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Discussion Starter · #3 ·
Battery to motor, motor to firewall, motor to frame, body to frame.
But if nothing else s grounded to the frame, why is that needed?
 

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But if nothing else s grounded to the frame, why is that needed?
I am far from an expert but if you don’t properly ground the core support and subframe you can sometimes get electrolysis which will destroy a radiator in short order. Better safe than sorry imho.

Just my two cents,
Don
 

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Discussion Starter · #5 ·
I am far from an expert but if you don’t properly ground the core support and subframe you can sometimes get electrolysis which will destroy a radiator in short order. Better safe than sorry imho.

Just my two cents,
Don
Ah ok, thanks
 

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1969 Camaro Restomod
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In addition to grounding my alternator to the engine (#8 AWG), I also installed a chassis ground thru-bolt in the forward part of the PS inner fender well and ran an #8 AWG wire from the battery terminal. Sanded to bare metal before locking in place. Also left the original core support ground. Battery ground terminal to engine is #2 AWG. Old adage is you can never have too many grounds. I also installed a new #4 AWG charge wire from Alternator to battery with a #8 AWG Fusible Link. Attached my reference "schematic" which shows the basic setup.

7FADC113-30A2-4995-86A6-E4FBA1DE558F.jpeg 7B70623D-4AA5-4BE4-8A9C-ECCF7146CE81.jpeg Front-Wiring-Layout-001.jpg
 
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I'm no expert and some might call me a hack, but this is what I did when I took my Camaro apart in my garage and put it back together just a few years ago.

Ground direct from battery to inner fender well then a jumper to the core support ... both pictured here.,
DSC_2612 by Larry Madsen, on Flickr

Large ground to Aluminum head
DSC_2614 by Larry Madsen, on Flickr

I have heard people say don't ground to aluminum. Usually saying aluminum is not a good conductor. That's B/S. If you look on conduction charts you will find the only metals that conduct electricity better than Aluminum are Gold, Silver and Copper ... Iron is well down the list, so much for that.

Then a ground strap from the rear of that same aluminum head to the firewall.
DSC_2615 by Larry Madsen, on Flickr

Those are all the dedicated grounds I have. Everything works just dandy.

I'll add: while I had everything apart I welded nuts to the back side of all these grounding points on the sheet metal panels ... the inner fender well, the core support and the firewall. All of those connections are a 1/4" bolt into a welded on nut.

IMO though, we never get complaints about a car being "too well grounded". If you think a strap from that aluminum head to the block might be beneficial or ease your mind a bit ... no reason in the world to not do it.
 

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Discussion Starter · #10 ·
One correction to my original post. I said battery was grounded to the head but it is grounded to the intake. I will move it to the head. Also going ground same head to firewall instead of the opposite as it is now.

My concern about grounding to aluminum was not due to it conductivity but rather that I’d always understood having different metals in the circuit could lead to corrosion and electrolysis.
 

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As I see it: Any way you go about it, if you have different metals all connected together ... they are all in the circuit, no matter what.

Maybe I need to study up on it to know what's what. ;)

I do know that I have been grounding to aluminum heads for over 20 years and I don't know of any problems being created.
 

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Getting ready to tackle some projects I’ve been putting off and one is my grounding situation in the engine bay. I currently have a heavy gauge wire from the wire to the aluminum heads. I am using they ground strap from the other head (header bolt actually) to the firewall that came with the car. IMO, it’s tiny and I going to replace it with something of the same gauge as my battery cables. I don’t have a ground strap from the engine to the subframe and don’t think I need one because nothing is grounded to the subframe. Thoughts on that? Also, should I stick with grounding through the aluminum heads or try to ground to the block? I use anti seize when I put a bolt in aluminum and wonder if that affects the grounding.
Your starter has a heavy gauge positive wire. The return path is the engine block. A heavy gauge wire is needed from the engine to the battery as you and Mr. Doug G mentioned.

Never Sieze is great for preventing galling in your aluminum heads. I don't know if it has any electrical conductivity qualities. I would put Never Sieze on the threads of the bolt. I would apply Burndy Penetrox A-13 to the head of the bolt and the electrical round crimp terminal. Penetrox will seal the electrical connection and prevent electrolysis (corrosion) between the aluminum, steel, nickel plated copper (the crimp terminal). After you tighten the connection, wipe away the excess Penetrox with a towel.



277171
 

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The big + cable goes to the starter, which bolts to the block. The big - cable should therefore go to the block.
All the small things such as lights etc. must have ground paths. Typically there's a ground to the nearest fender, and from the engine to the firewall. Then there are other ground straps from various locations.
A large assumption is the ground straps are still there and that electrical connections through bolts haven't corroded in 50 years.
 

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68 Camaro SS/RS, 454 BB 4 speed, 3.73 Posi, new paint, motor mods , trans and diff assembly. 2" Drop
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I am following this as I am putting my engine back in and want to install new battery cables and grounds. My car did not have a ground from block to frame strap other than the puny straps from firewall to sub frame and FW to each VC, which I understand is for the radio suppression. I see headlight harness grounds, and there is one missing from dash cluster to dash. Can you list any other important grounds to look for? In my case this probably explains why my dash tach is erratic.
 

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Probably 90% Electrical problems can be traced to grounds. I have battery in the trunk and Large Cable to the starter and Bat ground to the body. Then large cable from engine to the sub frame, solid mounts to the body and a few other grounds here and there I would have to track down. Have not really had electrical problems since finding a pinched wire in the dash. Good proper grounds make things play well together.
 

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Couldn’t agree more. My battery is in the trunk. Large ground to the body. Large ground from the body to the subframe. Large ground from the engine to the subframe. Alternator to engine.
 
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