Grounding Aluminum heads to iron blocks? I heard this from several sources as a must do item. Thing is I've never seen it done, soo is it urban myth or is there something to it?
When you run abunch of head bolts through it, I'd assume that would be a proper ground.
Not to say this in any way applies to alot of boats, but lets take mine as a example. Head studs set in lock tight or any kind if sealer. Not exactly conducive to the flow of electrical current, specially a low amp current draw like a ignition system, specially at low Rs. I am guessing less than 1 amp at idle for a MSD. Even less at the spark plug. Then throw on some FelPro MLS Stainless VITON coated head gaskets. Lets see, viton rubber coating on top of the worse metal imaginable for conducting electrical current. Mmmmm? Oh but wait, we still have the manifold, which the only contact with the block has a 1/4" of silicone between it.Agreed X the number of head bolts you have!
Nope. Never. Too much vibration going on. One large cable from the battery to the block for the starter only. EVERYTHING else back to the battery, or a junction lug on a seperate cable from the battery. Like this:Doesn't everyone use their motor as the main ground in a boat? Where else is there?...
Like I said, it doesn't apply to alot of boats, and may never cause an issue. But it just to easy to run a single wire from the head to the block. Detroit did it on more than a few engines. Usually at the back of the head to the chassis.Just for fun (must be bored), I went and checked resistance from head to block and there was 0 resistance.
Alum heads, Cometic MLS, bolts with sealant.
Soooooo...are we talking about the same kind of corrosion one would run anodes for? If so your thinking the anodes arent enough??Strange things happen when you apply current/voltage to poor conductors, that may otherwise seem ok. ARP black oxide studs, Cometic gaskets, ARP assembly lube, and teflon paste. Engine getting hot to cold, will do it's fare share of moving around. Galvanic corrosion
Actually Jim, its a horrible conductor, specially fresh water. Salt is considerably better, but still worthless.Water isn't the best grounding location, but water running through block to heads and then out would create some sort of ground.
Funny what you don't see during a race, but shows up when someone post pics. It was taken by Rexone, and he posted some on the V-drive forum.Bad ass pic in your sig line!devil It looks like Rusher is gettin some air.