47-59 Grounding Straps/Wires for motor

[_Ogre]

Originally Posted by Tempest67

Are 2 grounding straps enough?

not in my book. i used #0 welding wire from battery to a stud on my frame, then i added a separate wire to the body, 2 stereo amps and motor

those little ground straps are insufficient. on a cold morning your starter uses everything the battery can throw at it, this will be well over 200 amps. at a minimum you want a heavy cable from battery to motor. then you want an #8 min to the frame and the body. additional grounding if you do a big amp or 2.

don't use house wire, it it very stiff and has very few strands compared to welding wire or automotive wire

[28TudorAZ]

Here is what I used.
https://www.amazon.com/Standard-Moto...114317&sr=8-16

[Tempest67]

Thanks Guys,

I will add several

[dsraven]

you could count on the chevy 350 starter drawing in the neighborhood of about 250-350 amps depending on the starter used and the performance level of the engine.
for a 250-300 amp draw over a max 4 ft length you need a 4ga cable minimum. welding cable is great because it is more flexible due to the number of strands. a starter/alternator repair shop should be able to fix you up with the cable with the lugs pressed on and shrink tubed for a good price. I am not a fan of the cheaper cables that a lot of auto stores sell, they don't flex well because they have less strands plus the insulation used is also less flexible when you go to strip the cable for a terminal install.
I like to use a ground cable from the battery to the engine block and one from the block to the frame, large cable. a smaller cable should go to the body depending on what the amp draw of the accy's used will be. longer cable runs mean larger cable to handle voltage drop over the length.

https://www.crutchfield.com/S-BnuZ5p...uge_chart.html

[MiraclePieCo]

Originally Posted by 28TudorAZ

Here is what I used.
https://www.amazon.com/Standard-Moto...114317&sr=8-16

I think those old-style tractor braided ground straps are cool.

Originally Posted by jwhotrod

do yourself a favor, especially if you have aluminum heads or even an aluminum water neck, run ground wires from the heads to the block and then to your ground on the battery or frame. 90% of the electricity in the car is in the ignition (spark plugs, etc)
if you don't that electricity will find a ground path somewhere and it usually is not pretty. I have seen it turn throttle cables into toasters, completely erode water necks, it acts just like a EDM machine if you don't give it a easy path.

Once I was doing some welding on a project car and accidentally forgot my ground clamp and left it laying on the car. After the welding was done and I realized my error, I calculated that the current had actually gone through the rear end and back up the driveshaft to the engine and then the frame. Yikes.

[dsraven]

a young welder's mistake I have seen is when working in Ft Mcmurray in the cold of winter the welders would weld on an extra lump to the grouser bars on the track pads of the dozers. this is for traction on ice because a dozer pad is fairly flat so going ahead and back the tracks will rather spin out instead of grip plus they can be slid sideways fairly easily on ice, like skates, if it is a side hill so the extra lump in the middle of the track pads helps stop or slow down the process. anyway, the dozers are put up on stands and the welder welds on pieces a few inches long onto each track pad, staggered so they don't all line up in the same footprint as the track spins around. long story short the inexperienced welders sometimes are not told to place their ground on each pad as they weld, instead of on a single pad for the whole job. if they don't do it right then welding current will pass through the bearings in each chain link of the track and leave a mark so the track wears out in fairly short order after the grouser bars are welded up. same goes for welding on vehicles if welding on something place the ground close to the weld, on the same part preferably, to eliminate the current flowing through something else first before making it's way to the weld