electrical grounding of engine to airframe

[rjtaylor]

I am in the process of wiring the bearhawk fuselage and have a question. the grounding of the engine to the airframe is important. how are most doing it? the dynafocal mounts are not the correct way to ground it. any suggestions would be appreciated.

[N942VT]

Copper strap from the engine block directly to your main ground block on the firewall, you do have a ground block right?

[jaredyates]

I used 4-ga welding wire with ring terminals in each end. One ring to a bolt on the engine case, and one to the ground point on the firewall.

[rjtaylor]

Ok. thanks. I do not have a specific grounding block, but I intend to use two of the welded tabs that are used to secure the firewall to the fuselage tubing for grounds. the paint has been removed and I planned to use a single or two smaller double straps of the braided type. this seems to be what jaredyates used.

[alaskabearhawk]

Here's how Ron Jones did his:

http://www.mykitlog.com/users/display_log.php?user=jonesronc&project=191&category=2218&log=78255&row=21

[jaredyates]

I used an insulated, stranded welding wire from the local welding shop. Just go in there an tell them you need a few feet of it, but of course don't tell them what it's for! It's very flexible, durable, cheap, and available

[N942VT]

That ground block that Ron shows is a really good idea, bring all of your ground wires back to a central point, from there to the battery. It save allot of ground related issues later on. Bob Nuckols in his book 'The Aeorelectric Connections' calls out a central ground with good results.

[Phil]

Get a braided ground strap from your local auto parts store. Works great.

[Denali]

Get a braided ground strap from your local auto parts store. Works great.

@ Phil: Would you recommend braided stainless steel strap or braided copper ?

[Battson]

Remember this is in series with your alternator and starter motor - that's the greatest demand. It really needs to be the same size as your starter cable at least, to avoid creating larger resistance and becoming very hot during a prolonged start.

I just used the same heavy gauge cable as used for my starter. Ran it from a spare nut on the accessory case to the 'star-point' earth.