Proper grounding of the engine electrical systems is necessary for proper engine performance and reliability. Improper grounding will result in uncontrolled and unreliable electrical circuit paths.
Uncontrolled engine electrical circuit paths can result in damage to main bearings, crankshaft journal surfaces, and aluminum components.
Uncontrolled electrical circuit paths can cause electrical noise which may degrade engine performance.
To insure proper functioning of the engine electrical systems, an engine-to-frame ground strap with a direct path to the battery must be used. This may be provided by way of a starting motor ground, a frame to starting motor ground, or a direct frame to engine ground.
Ground wires/straps should be combined at ground studs dedicated for ground use only. All grounds should be tight and free of corrosion.
All ground paths must be capable of carrying any conceivable fault currents, and an awg #0 or larger wire is recommended for the cylinder head grounding strap.
The engine alternator should be battery negative (-) grounded with a wire size adequate to handle full alternator charging current.