Alfa Romeo Forums banner

magnesium veloce air plenum

2K views 8 replies 5 participants last post by  Gordon Raymond 
#1 ·
So what's the story on these? I thought it was aluminum, but realized mine is magnesium.

Thanks!
 

Attachments

See less See more
2
#3 ·
Hi HUD

Your plenum top is a rather rare item, firstly being the round snorkel version unique to the Giulia SS only & secondly being magnesium.

It appears that air plenums & oil pans were made in magnesium for the 750/101 cars, no one has thus far come up with definitive proof of who actually made them, but we 'suspect' that they were cast in the Factory Foundry as they are absolutely identical to the aluminium ones and carry the same part numbers.

Many of the racing guys used magnesium oil pans and plenums back in the day, (the bell housings & tranny tail housings came with the GTA's). I know of a few Lightweights that have magnesium oil pans and or plenums, so that was late '50's early '60's. We are not sure if they were supplied OE or aftermarket...... Lightweight 04700, the Ex Jean Rolland car was raced in period with a magnesium oil pan which the current owner, Stuart still has with the car.

Magnesium is a can of worms as it's incredibly unstable & *really* wants to revert to a powdered state, so even the act of handling it and depositing skin oils etc can have an affect on it, whatever you do, do NOT attempt to clean it, that just accelerates the solid-to-powder process.

There are many others here, way more learned than me who can advise you on what to do with Magnesium, Gordon Raymond has dealt with a lot of these bits, he will no doubt offer sage advice on the practical aspects of living with magnesium bits on your car.... take heed !

Ciao
Greig
 
#8 ·
If it is magnesium then I would guess lots of value. But probably not easy to determine that value.

Ken
 
#6 ·
There is a GTA "street" version of these. Rough exterior finish. Check the casting number under the snorkel. Looks like this one on a complete GTA induction set up.
 

Attachments

#7 · (Edited)
I wonder how you know it is magnesium? Did you weigh it and do a volumetric displacement of water to determine its volume and then calculate the density, p = M/V, and find something close to 1.738 g/cm3. (cm3 is cc or cubic cm)

Or have it assayed? Or by its looks? Or weight comparison to an identical Aluminum (heavier part), or special markings as on some GTA parts.

Density of aluminum is 2.70 g/cm3.

Electron, a magnesium alloy name I often see associated with Alfa has up to 9.5% alloy added the main of which is Aluminum.

Just curious

Ken
 
#9 ·
Hi Ken,
The one I pictured is off of one of AUSCA's 65-66 GTA's, is easily 1/2 to 2/3 the weight of the 105 casting number counterpart in aluminum. It was also factory painted as you see, zinc chromate with aluminum colored lacquer on the exterior. It's the GTA Electron alloy. The pictured set-up even has the period "odd" 12mm hex GTA insulator / isolator nuts. I just photographed this assembly.
 

Attachments

This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top