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I once read somewhere about folks grounding their alum heads to the block or chassis.....any truth to this? I've always run a strap from my chassis to the block, but do I need another for the heads now too?

I have read that too.BUT
I have never done anything except to bolt the engine between the engine plates.

Your trying to give a path for stray electrons to go back to the battery via the frame, not the coolant into the cast iron. If the electrons travel through coolant into the cast iron then due to the dissimilar metals you actually create a battery, and electrolysis. This will show as wicked corrosion in the cooling passages in an aluminum head and in an aluminum intake.
A few companies now make a "Sacrificial Anode" that is made out of Zinc and you can insert it somewhere in the cooling system. The stray electrons attack (actually return to ground via) the softer Zinc instead of the often times expensive aluminum cylinder heads. All this shit takes place on the atomic level, it's a slow process, but it does happen.


It's the same principal as a skeg on the outdrive of a boat.

Thanks for the reponses. So you're saying that in a perfect world, I'd have the heads AND the block grounded to the frame (or the head to the block and the block to the frame), to prevent the process stated above?!

This is true!

I found excessive corrosion in my Pro1 headed SBC when I tore into it for my current rebuild.
It only had 1 ground from the battery neg terminal to the block, that's it!

I don't think you can have too many grounds.

Do what you want but I WILL BE installing a ground from my battery negative terminal to the frame, another ground from that point to the engine block, each head will get a cable to the frame, and there will be a smaller ground wire (8 gauge) to the body.

Also, some of the import crowd replaces stock ground wires with larger cables to help reduce resistance. They "claim" Hp increases with this. Take it for what it's worth.

1 last thing....use good cable / wire with properly installed ends / connectors !! Not that real rigid crap with about 10 strands !!

TC

one other thing to consider is, if your running an electric WP, you should ground the heads and wp and run an zinc anode in the cooling system.

flex a lite sells a anode that screws into a 3/8 pipe opening.
they also have radistor caps with a built in anode in them.

All home hot water heaters come with anode rods,I think it would be best to run a extra ground wire from there to your "Johnson rod"too.....OLDHEAD