Grounding

[sdsurf]

Where is the location for the ground on the engine? 521/L16

[datsunaholic]

Stock, the negative battery cable went to a bolt on the side of the block below and behind the fuel pump. It is best, however, to add a few particularly between the head and body.

[sdsurf]

Stock, the negative battery cable went to a bolt on the side of the block below and behind the fuel pump. It is best, however, to add a few particularly between the head and body.

 

Got any pics?

[datsunaholic]

No, I don't. Heck, maybe the L16 only had the point on the head (where the lifting eye goes). I'm too used to where the L20B ground bolt goes. I've used both. And I don't have a stock 521 to look anymore.

[hang_510]

the L16 only had the point on the head (where the lifting eye goes). I'm too used to where the L20B ground bolt goes. I've used both.

the block is a better spot than the (AL)head, the block-head combo :lol: would be easy to do.

[dat521gatherer]

i would love to see a factory pic of this answer myself.

 

iv'e always used the fuel pump stud for the lifting eye.

[dat521gatherer]

looking at a photo in the owners manual the battery ground goes to the lifting eye next to the fuel pump.

[mklotz70]

pg 220 of the factory manual(avail on the tech page of http://www.olddatsuns.com) only shows the battery ground cable going to the alternator body. That would be stock.

 

Running the ground to the block helps with the return side from the starter, which carries more current than all the other systems combined. Grounding the head helps with the return circuit from the spark plugs. I highly recommend running a ground from the eng to the body. The only stock ground between the two that I know of is a 10ga wire between the bellhousing(near starter) to the frame. Since all the lights/wipers/radio/wiper...all ground to the body, an additional ground from the bat to the body is a good idea. You can either run it from the eng to the body, or directly from the bat.

 

Anyone wanting the strongest ignition should run a dedicated ground to the distributor body....points or EI.

[datzenmike]

Mike's right on this. I had a catastrophic short from the POS to the body. The only path to the engine block was down the throttle cable... which got HOT! the plastic melted and hardened around it. No throttle at 1:30 in the morning with 15 miles to get home.

 

On some 720s the NEG cable has a lug on it about a foot from the battery that bolts to the inner sheet metal fender then on to the intake manifold.

[dat521gatherer]

yeah that owners manual was a guess. i love to stroll through the 521 service manual just to look at the pics. on that diagram it does show the ground cable going to the alt but i cant tell that it's connected to the top or bottom mount. maybe i'll stroll through the book some more and try to find an actual pic.. best book to have if you have a 521.

[dat521gatherer]

sycloned916's alternator thread has a great pic of the stock negative battery cable mounted to the front of the top alt bracket bolt. its a j13 engine.

[sdsurf]

ok... Should I ground the block (engine) to the fire wall? Negative battery to alt mount? anything else?

[dat521gatherer]

take the ground wires off your voltage regulator mounting screw/bolt and clean/sand/dremel the surfaces til they shine. actually take the whole volt reg off and clean the back mounting surfaces and the surrounding bolt holes where they go. one of the best preventive maintenance you can do.