[461-69bird]

Where do you recommend I have my earth straps? Currently don't have enough, just from negative post to engine block and starter motor to frame mount on crossmember. Is it worth earthing alternator as well?
Ali heads iron block.

[steve25]

The factory set up was just two flat braided un insulated ones.
One from the rear of each head to the fire wall besides the main ground from the battery to the block.

That all said it would not hurt to have a jumper from that main ground to the rear of the passenger side head.

[Half-Inch Stud]

Everything runs better when the Alternator& Block& Driver Head are considered the best GNT. Frame not so good.

[roy381]

What material is best, copper?

[johnta1]

Yes.

Is it worth earthing alternator as well?

Some alternators have a threaded hole for a ground attachment. Wouldn't hurt to add a wire there to battery.

[steve25]

Jeg’s has these which are like what ran from the rear of each head to the firewall.

The one pictured may not be the length nor bolt hole size you need you need.

Factory on the heads would have been 3/8” bolts.

[P@blo]

I run a redundant ground from the frame to my transmission bellhousing paired with the braided engine/body grounds. And another distributor to block ground, as per Jim Hand, doesn't hurt either if running an HEI.

[461-69bird]

Originally Posted by steve25

Jeg’s has these which are like what ran from the rear of each head to the firewall.

The one pictured may not be the length nor bolt hole size you need you need.

Factory on the heads would have been 3/8” bolts.

Steve, even if my heads are aluminium?

[steve25]

So what was your issue with the motor not cranking over that you had earlier in the week?

[461-69bird]

Either bad earth or something to do with the ignition switch. Had it off to check voltage, so whether I adjusted it when refitting, not sure.

[Half-Inch Stud]

Copper best in auto.
Aluminum good but attachment points fraught with electrolysis corrosion.
Steel not so good, but in a penny pinch, GM and others will show you just how good running High current through Steel is.

Compromises done, and fix-able wth dedicated copper wite to block or darn close to it:

Rear lamps in bumper ought get dedicated copper wire run to Dash Firewall. Then firewall get run to ALT back boss.

Headlamps ought get dedicated copper wire run to alt back-boss, or firewall where ALT wire is.

Starter ought get shiney metal mount surfaces to block. Starter Steel shell ought get scraped shiner where the aluminum Nose contacts the Steel case..

Dash cluster ought get a dedicated copper run from sheet metal case to firewall.
Stereo GND ought get copper run to firewall.

So inside firewall point under dash, and underhood firewall point to transfer to Alt Case.
Done.

[HWYSTR455]

Copper, yes.

I go from batt to frame to block with 4g SGT grade wire. Copper crimp lugs with shrink tube. The frame point has a rivet-nut in it to ensure total contact. I connect to a bolt hole on the block.

Back of alt to that same bolt hole on block. (6g SGT grade wire)

Core support & fender to batt neg. (10g GXL grade wire)

Firewall to block. (8g GXL grade wire)

Body pinch weld in rear inner wheel well/rocker/floor pan area to frame, both frame & body using rivet-nuts. (6g SGT)

It is possible to have too many grounds. You can create 'ground loops'.

Never use 'hook-up' wire or generic parts store 'primary' wire. Use TXL grade wire in high heat areas, SGT for batt cables, and GXL everywhere else.

With quality wire, you can use 1 or 2 smaller gauge wire with no drop in voltage/capacity.

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[HWYSTR455]

Under the dash, I use the lower brace of cowl where the dash attaches by driver door to ground everything under the dash. Did a rivet-nut with a stud, and everything goes there. It will feed off the firewall.

Keep in mind the column requires grounding. The copper strap on the rag joint needs to be good too.


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