The Stovebolt Site Forums The Shop Area The Electrical Bay V8 swap in '63 - how ground the system?

I'm finishing up a V8 swap in my 63 suburban. I'm finishing the wiring in the engine compartment and I was wanting to know how this system should be grounded. The battery is grounded to the block. Should the engine block also be grounded both to the body and the frame?

usually grounding to the cab will do it - the engine and cab mounts seem to take care of the frame, but it's good on the bed to have a ground from the tailend to the frame to insure the taillights get a good ground

Bill

I have a related question. I am finishing up my 53 big bolt with a 235 engine. When I got the truck the battery was grounded to the frame. I can't remember about other grounds. While I was working on it the only connections I had were the positive to the starter and the ground on the frame. Everything seemed to work ok. The truck started and ran. I know there are usually other grounds, so I ran a wire from the motor to the frame also. Question: Is this ok? Should I have done it some other way, or do I need other grounds, for example, to the cab? Thanks Allen

Just so long as there are connections between everything, it doesn't matter where you ground what.

I have my battery grounded to the tranny. The tranny grounds to the frame via the crossmember, and to the engine block, via the bellhousing.

The body grounds via its contact with the frame.

All of my various electrical systems (horn, headlights, brake lights, coil) are grounded to something metal, and since all of the metal is connected somewhere along the line, I've got ground everywhere.

If there has been any modification done to your frame so that the engine or tranny doesn't make contact, then I would make sure that I had a wire running from the one to the other. In a stock situation, there won't be any reason to add ground wires except to ease your mind.

-Brendan

Too many gounds never hurt .
I normally connect the battery ground wire to the block. Then I get a couple of grounding straps and connect the block to the frame and another from the block to the body. The pic below sells for about $3

[img]http://www.sage.lunarpages.net/wfc/hw007.jpg[/img]

You can,t depend on engine & trans. being grounded to frame. They are mounted on rubber. Iv,e seen choke cables light up trying to serve as grounds. If the bat. is grounded to frame you need a heavy gauge cable from frame to engine or trans. If it is grounded to the engine a 10 gauge wire will do. It,s also a good idea to put a ground wire to the body also.

Thanks guys. Mine is working now. but just to be on the safe side I will change it. Allen

FYI - If you are running a fuel injected motor, you need to run grounds to EVERYTHING.

grounds...just the word can cause night terrors.

When their in your coffee I agree..$1.75 a 16oz slug out my way!


Stuart

These old trucks didn't have much for ground wires. But as the design advanced, the number of cables increased. It's one of those things that you can't have too many of. As the truck gets older, rust and corrosion get worse and cause problems with grounds.

My recommendation is a ground cable from the battery to the engine. You also need a 10 gauge minimum to the frame. A wire to the cab, bed and radiator support can be attached to the frame. This will get around all the rubber isolation mounts.

When connecting the grounds I use fine sandpaper to clean the rust and paint from the mating surfaces. Don't depend on the bolt threads to carry the load. Apply a dab of di-electric grease between the bared fittings and metal and bolt together. This is an important step with anything transistorized, like HEI and radio.

You can buy a tube of di-electric grease at the parts store. It's a silicone base with a filler added that conducts electricity.

I think that one purpose of dielectric grease is to prevent the conduction (especially arcing) of electricity (also prevents rust, corrosion, oxidation, and rubber parts sticking to metal/ceramic parts).

If you want to enhance conduction and are not concerned about arcing (such as battery cable connections to the battery and/or frame-ground), then a conductive anti-corrosive grease will serve that purpose.

http://www.tessco.com/products/displayProductInfo.do?sku=437469&eventPage=1
http://www.omgtr.ca/technical/General_Technical/grounding.htm
Eastwood

Supposedly, 6v vehicles had 2 gauge battery cables and 12v vehicles have 4 gauge battery cables. Often, people have the 4 gauge cables on their 6v vehicles. This is inadequate. Many people suggest 1 gauge battery cables for 6v vehicles and some use 0 or 00 (1/0; 2/0) gauge battery cables. Such cables are available (or can be made) at a good truck or tractor parts supplier. Be careful, most people behind the counter think that a smaller number means a smaller thickness of cable.

A few months ago, I finally got tired of hard starting (especially with a warm engine) and I installed 2/0 gauge battery cables (positive and ground). The engines spins very nicely now - hot or cold. The thickest braided ground cable that I could find was 2 gauge, so I used 2/0 gauge round cables.

It seems that 6v GMC New Design trucks ran the ground to the transmission (and, I guess, a ground cable was then run from the transmission/block to the frame). Chevrolet Advance-Design trucks ran the ground from the battery to the frame (behind the battery box) and then from the frame to the clutch-housing (to the bolt that holds the foot-starter mechanism to the clutch housing). There is also a ground cable from the head (behind the distributor) to the firewall (this is shown in the radio installation manual. I think).

Fred has it right Tim - dielectric grease insures good conduction, particularly by excluding moisture and preventing corrosion - in a rainy climate it's an excellent thing to use on nearly all electrical connections that are subject to corrosion/oxidation problems, like battery terminals and tail lite bulb bases

Bill

Bill,




Stuart

what Stuart? semantics again?
something that prevents 'conduction' is an insulator
I guess dielectric grease doesn't include an additive that 'conducts', so yeah, Fred is wrong too, but it also doesn't 'insulate' the mated surfaces, it simply seals them from the environment, promoting continued good 'conduction'

I think what happens is the firm mateing of the surfaces actually displaces the material to a film thickness that doesn't actually 'insulate but, by preventing the invasion of varying humidity, prevents oxidation

so, dielectric grease insures continued conductivity, it doesn't prevent it - unless maybe it's slathered on pretty thick - works extremely well to smear a light application to tail lite bulb bases when you install them to avoid the oxidation that frequently happens to distrub good conductivity

Bill

So, "If you want to enhance conduction and are not concerned about arcing (such as battery cable connections to the battery and/or frame-ground), then a conductive anti-corrosive grease will serve that purpose."

I use dielectric grease for small electrical connections, to prevent corrosion and to prevent arcing (when multiple connectors are close together). The physical mating of the two metal surfaces will "break" the dieletric (non-conducting) surface and allow a clean metal-to-metal connection.

I will stick to using a conductive, corrosion-preventing (anti-oxidant) grease on my battery ground cables (and, carefully applied to the hot-terminal-bolt on my starter).

and those w/ dielectric grease at hand can safely use it for the same purpose? works well for me, so I thought it might be helpful to others to point out that they won't be making bad [non-conductive] connections using it

I'm unfamiliar w/ 'conductive anti-corrosive grease', is there a brand name attached?

Bill

Kopr Shield (cited in the three links in my first posting).

It is also sold at many electrical contractor supply houses.

Tim

ok - I followed the links, just didn't know colloidal copper was grease - I know it's commonly used on boats and protecting aluminum wires at dissimilar connections

Bill