battery Reloc. Wire Gauge Question - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Bigsyke · 09-04-2009, 02:28 PM

Ok let me ask you;

Why is the engine block grounded at all? let alone in 2 places almost opposite of eachother (IM then the rear of the head), We all know the sensors/harness grounds could be directly extended to the chassis itself. If the engine is grounded to the chassis, why go through the engine. We also know pure water will not conduct, but once a coolant or contaminant is added - galvinized corrosion, electralysis will occur on almost all aluminum or soft metals. Why do we isolate the heatercore, and radiator from the chassis.

ive seen service bullitins say the engine is grounded in 2 opposite places is mainly for a path of least resistance so an underpar electrical system will not energize the aliminum. However if the chassis becomes energized the current can flow back to the engine block.

My understanding is by grounding only 1 engine ground to the same spot as the bat - on the chassis, in the event of the chassis becoming energized from an underpar electrical system, the current can skip the chassis and directly access your engine block. Every aluminum engine ive seen has spaced out the -bat ground from all the other grounds, because the chassis is like an insulator, the engine is also like an insulator thus the sensative sensor grounds ended up being on the engine not the chassis. People have ran that circle of earth grounding systems and had a hole eat right through the water pump, radiator and heater core. There is just too many factors you have to dynamicaly acount for, like having an MSD system.

Thats just what ive heard/read, ive never seen anything like that, but ive been toying with these stupid grounding systems from years on 5 different cars, I also picked up about 300ft of 2-4ga wire when Circuit city went under. I just upgraded the OE wiring and found that OE isnt "damaging" anything. But your diagram does seem interesting. Why do you have only 1 ground going to the chassis? doesnt this leave room for energy to pass through half the engine?

09-04-2009, 02:28 PM	#22
Bigsyke Zilvia FREAK! Join Date: Jun 2008 Location: NA Age: 40 Posts: 1,342 Trader Rating: (0) Feedback Score: 0 reviews	Ok let me ask you; Why is the engine block grounded at all? let alone in 2 places almost opposite of eachother (IM then the rear of the head), We all know the sensors/harness grounds could be directly extended to the chassis itself. If the engine is grounded to the chassis, why go through the engine. We also know pure water will not conduct, but once a coolant or contaminant is added - galvinized corrosion, electralysis will occur on almost all aluminum or soft metals. Why do we isolate the heatercore, and radiator from the chassis. ive seen service bullitins say the engine is grounded in 2 opposite places is mainly for a path of least resistance so an underpar electrical system will not energize the aliminum. However if the chassis becomes energized the current can flow back to the engine block. My understanding is by grounding only 1 engine ground to the same spot as the bat - on the chassis, in the event of the chassis becoming energized from an underpar electrical system, the current can skip the chassis and directly access your engine block. Every aluminum engine ive seen has spaced out the -bat ground from all the other grounds, because the chassis is like an insulator, the engine is also like an insulator thus the sensative sensor grounds ended up being on the engine not the chassis. People have ran that circle of earth grounding systems and had a hole eat right through the water pump, radiator and heater core. There is just too many factors you have to dynamicaly acount for, like having an MSD system. Thats just what ive heard/read, ive never seen anything like that, but ive been toying with these stupid grounding systems from years on 5 different cars, I also picked up about 300ft of 2-4ga wire when Circuit city went under. I just upgraded the OE wiring and found that OE isnt "damaging" anything. But your diagram does seem interesting. Why do you have only 1 ground going to the chassis? doesnt this leave room for energy to pass through half the engine?