It's true that Electron or any other high magnesium alloy will oxidise quickly if left exposed to air. Generally, Alfa coated all of their mag. parts, so I don't know why a cam cover would corrode more than a bell housing or front cover.

 

Those we used, and I still use are painted magnesium. The item that was most often replaced with aluminum was the bell-housings which cracked made of magnesium. This was usually in the heat of racing, and could possibly be blamed on rough track surface or rougher driving or shifts.
I still have an alfa 101 1300 truck bell-housing set up for column shift. These were thicker aluminum than those for passenger cars, and, long ago, were a preferred replacement for cracked or broken magnesium housings.

 

The reference should be to the front timing cover rather than the valve cover. Unless specially treated, the water pump area tended to erode. Production was switched to aluminum timing overs when this was recognized. Today this can be dealt with with resin impregnation and special coatings.

 

Valve cover corosion

1. The valve cover in elektron ( magnesium/aluminium ) was only for the early 1600 heads without the 2 bolts in the front. Also these heads had a small part of magnesium to enlarge the strength .Later 1300 GTA heads are from aluminium/silicium mixture and the covers are from the same metal.

2. The tendence for cracking in the bellhousings comes from vibration of the engine and to heavy starters and has nothing to do with the material. Also late 2000 bellhousing are often cracked! for the same reason.

3. original GTA elektron parts were never coated , they are bare metal!


regards
Uli

 

and they leak big time!

 

(That's why if we use them we either paint or resign impregnate them.)
{Then they only leak a little!}