Im relocating the battery on my 64 Cutlass to the trunk. Decided to use Olds engineering to do so. So I found 1966 442 OAI instalation instructions. Best I can tell, they did not run the negative cable to the engine. I will run mine to the engine however , similar to the positive side. As a curiosity, did Olds run the neg cable to the engine?

 

NO, mine is located just about under the trunk on the right side of the frame rail.,cable is really heavy duty like 4 gauge welding cable.
plus, in the engine compartment there is a big ground cable open strand 1" wide from the block to frame. I did post pictures of mine some months back under pictures of 66 olds 442, where there are some pictures of this....

 

The frame is conductive and everything else is grounded to it. While steel is not as good a conductor as copper on a per-square-inch basis, there are a LOT more square inches in the frame rails than there are in a battery cable. Running the cable all the way up may actually reduce conductivity. In any case, you'll want to upsize the cable. If you do use the frame, be sure the connection points are clean and use dielectric grease and star washers to ensure good contact.

 

The most important single factor is the integrity of the frame. A frame replete with significant rust/corrosion will introduce and increase attenuation of electron flow e.g. hinder electron flow. While there exists far greater square inches of steel - it depends on the condition of that steel. Rusted steel does nothing for electron flow - it will, in fact, impede electron flow.

 

If the surface rust is deep enough to significantly impact conduction, there's a much bigger problem with that frame...

 

That is, in fact, correct. And, in addition, every device contained w/in the path contributes to electron flow - either increasing, decreasing or not influencing electron flow. The best manner to determine which remains the best opportunity is to measure resistance and pick the path of least resistance

 

Thanks for the replys . I am not going to run a cable to the engine. OAI instructions,. shows factory supplied ground ,that normaly went from engine to batt, switched engine to frame. Of course there will be a cable in trunk from batt to frame. Even though the instuctions dont show that cable. That coupled with the forum,GURUS knowlege has conviced me a cable neg cable from trunk to engine is not needed. Thanks Guys

 

I relocated my battery to the rear storage compartment and grounded the negative post to the frame nearby. I also put a ground between the engine block and frame at the front.

I used 00 cable for the positive to the front and for the two short negatives.

It worked very well.

I never thought to copy the early W-30s, but research led me to do the same thing that you will be doing.

 

I not only ran the ground to the frame in the rear, but used the large wide ground strap on drivers side like the instructions show. I ran a short cable from the front passenger frame to the engine block as well. Was that necessary? Probably not but that’s what I did along with sanding frame to metal and using star washers. My frame had minor surface rust only.

 

The ground has to be grounded to the cylinder head, just like the factory does it. It’s grounded that way because the spark plugs ground is the the plug threads/electrode.

it should not have to pass through a head gasket or intake gasket. there should also be a similar ground from the body shell to the frame to avoid body mounts

 

Seems like the head bolts would provide a sufficient ground from the block to the head.

 

I figured the grounding to the block sufficiently run through the head bolts, does it really make a difference? If so I will put my auxiliary ground to the head. I already have the factory big flat ground strap to the head. The one I put on the passenger side is more than likely not necessary.

 

my 70 is grounded to the block behind the PS pump.
then there is a braided ground to body from passenger side rear head.

 

I guess the millions of cars built by Olds was grounded wrong, who would have thought it?

 

Does anyone have the actual '66 diagrams from the PIM?

 

The 66 instructions are not in the PIM but I have a copy.

 

they are grounded at the head to the firewall and then under dash grounds .

have a look someday.

its even more critical on EFI systems. Both heads , if it’s a V8 ,should have their own ground

 

Yes I know about the ground from the head to the body but the topic was the negative battery cable ground.

 

And he said they didn’t run the ground to the engine ..which I responded to by saying it should have one from frame to body and from body to cylinder head..

The ground from firewall to head , and then from body to frame is very important, especially when using a trunk mounted battery.

Do you want me to explain how primary and secondary grounds work?

 

They did run the ground to the engine...by using the frame.

 

yes, he was asking that. If you want to live in 2024, add another one from body to frame. I explained why

 

This is the instructions for Outside Air Induction installation. I found online

 

Thanks for posting the .pdf file. Sure enough that last page mentions "negative cable fastening to frame." Does your car already have OAI?