Electrolysis ?

Just a question : when I took off my intake manifold. I noticed that there was some white powder on the manifold side of the heads and that my galvanised intake manifold bolts were rusted... As this is the first time I used aluminum heads I was kind of surprised. Anything that needs to be done to counteract ?

I have a chart at home that shows the metals we use and their reaction with each other. I remember that gold is happy with all other metals.

A good anti-seize will keep the galvanic corrosion to a minimum.

I'll make myself a note to scan and post that chart.

The chart is known as the galvanic table:

Active (Anodic)

Magnesium
Mg alloy AZ-31B
Mg alloy HK-31A
Zinc (hot-dip, die cast, or plated)
Beryllium (hot pressed)
Al 7072 clad on 7075
Al 2014-T3
Al 1160-H14
Al 7079-T6
Cadmium (plated)
Uranium
Al 218 (die cast)
Al 5052-0
Al 5052-H12
Al 5456-0, H353
Al 5052-H32
Al 1100-0
Al 3003-H25
Al 6061-T6
Al A360 (die cast)
Al 7075-T6
Al 6061-0
Indium
Al 2014-0
Al 2024-T4
Al 5052-H16
Tin (plated)
Stainless steel 430 (active)
Lead
Steel 1010
Iron (cast)
Stainless steel 410 (active)
Copper (plated, cast, or wrought)
Nickel (plated)
Chromium (Plated)
Tantalum
AM350 (active)
Stainless steel 310 (active)
Stainless steel 301 (active)
Stainless steel 304 (active)
Stainless steel 430 (active)
Stainless steel 410 (active)
Stainless steel 17-7PH (active)
Tungsten
Niobium (columbium) 1% Zr
Brass, Yellow, 268
Uranium 8% Mo.
Brass, Naval, 464
Yellow Brass
Muntz Metal 280
Brass (plated)
Nickel-silver (18% Ni)
Stainless steel 316L (active)
Bronze 220
Copper 110
Red Brass
Stainless steel 347 (active)
Molybdenum, Commercial pure
Copper-nickel 715
Admiralty brass
Stainless steel 202 (active)
Bronze, Phosphor 534 (B-1)
Monel 400
Stainless steel 201 (active)
Carpenter 20 (active)
Stainless steel 321 (active)
Stainless steel 316 (active)
Stainless steel 309 (active)
Stainless steel 17-7PH (passive)
Silicone Bronze 655
Stainless steel 304 (passive)
Stainless steel 301 (passive)
Stainless steel 321 (passive)
Stainless steel 201 (passive)
Stainless steel 286 (passive)
Stainless steel 316L (passive)
AM355 (active)
Stainless steel 202 (passive)
Carpenter 20 (passive)
AM355 (passive)
A286 (passive)
Titanium 5A1, 2.5 Sn
Titanium 13V, 11Cr, 3Al (annealed)
Titanium 6Al, 4V (solution treated and aged)
Titanium 6Al, 4V (anneal)
Titanium 8Mn
Titanium 13V, 11Cr 3Al (solution heat treated and aged)
Titanium 75A
AM350 (passive)
Silver
Gold
Graphite
End - Noble (Less Active, Cathodic)

That's the longer version of what I have.

Belgian1979vette said:

Just a question : when I took off my intake manifold. I noticed that there was some white powder on the manifold side of the heads and that my galvanised intake manifold bolts were rusted... As this is the first time I used aluminum heads I was kind of surprised. Anything that needs to be done to counteract ?

Click to expand...

Summit sells a sacraficial anode that goes where the radiator drain petcock is located. That, and religious changing of the antifreeze every other year is about all you can do.

I guess you could be using pure ethyleen glycol. However I wouldn't know where to get it.

Belgian1979vette said:

I guess you could be using pure ethyleen glycol. However I wouldn't know where to get it.

Click to expand...

Water transfers heat better. Pure E.G could cause overheating. My statement actually pertains to renewing the corrosion inhibitors that is mixed with it.

big2bird said:

Summit sells a sacraficial anode that goes where the radiator drain petcock is located. That, and religious changing of the antifreeze every other year is about all you can do.

Click to expand...

For future reference

http://store.summitracing.com/partdetail.asp?autofilter=1&part=FLX-32060&N=700+115&autoview=sku

Over here, there is a radiator cap that has a sacrificial anode attached to it. Zinc or magnesium. Can't remember. A good misture of antifreeze and deionized water is suposedly the hot tip.

On CF Tom Dewit replied and said that the secret is to use distilled water and a 50/50 mix as pure antifreeze will cool less (as said by some).

Belgian1979vette said:

I guess you could be using pure ethyleen glycol. However I wouldn't know where to get it.

Click to expand...

Can't buy it at a parts house?? U gotta be kidding....why NOT?? common enough for some 100 years now.....

IMO, the most electrolysis is between iron blocks and aluminum heads...close to each other,...the rest of the system is no more problematic than with brass....and a 50-50 mix runs for decades even....

I remember my mother's '63 Olds F85 predecessor to the Cutlass 442, and it sitting in the garage for some 25 years, only had 35,000 miles on it the brakes were shot, the chassis rusted out, exhaust was garbage from all the condensation of Maryland seasonal changes....

but the engine RAN fine not an issue.....had that aluminum 218? cu inch engine, the one Land Rover ran forever yet....aluminum with iron cyl liners...

so go figger....