Ground wire question

[Drcoffee]

I am making up a new battery ground cable to ground to the engine block. I plan to use a copper eyelet lug at the end of the cable to bolt it to the iron engine block. Is there going to be a reaction between the copper connector and engine block? Should I use an Aluminum crush washer between the copper a iron?

 

[ConstantFix]

There will be no reaction. Just make sure the block isn't dirty and that it's a smooth grounding surface.

 

[Drcoffee]

I plan to use a little dielectric grease on the contact points. I was afraid it would corrode and break contact over time. Thx

 

[Swede]

Penetrox works good too. It's designed for use with dissimilar metals.