tires and wheels 3 piece magnesium Alpina wheels

[mccusername]

Thanks Mark. I'll get some pictures next time I'm in the shop with them.

 

I have to admit, I'd be tempted to run them, danger be damned, but I think it might be a while before a find a random 4th 14" wheel center to complete the set. 

[markmac]

I would run them.  Have them magnafluxed first to make sure their isn't a 'hidden' issue with any of them.  I would have them epoxy primered and then painted.  To the extent you can keep them out of rain/wet - the better.  It's not like you are putting 20 or 30k miles on your car a year (guessing).

 

You may be able to find a foundry that can make a casting of your wheel center.  Just a thought.  You might be able to recoup some of your cost by casting a few sets and then selling them off.  No clue on what the cost of that could be though, someone here may know better.

[jp5Touring]

Worked with magnesium wheels for five years. Yes their very fragile for sure. 

When they break they tend to break big time, like two or three pieces.  

 

Cool wheel but wouldn't run on the street.

[mccusername]

I imagine it depends on the specific alloy, right? I have vintage Cromodora CD32s on a car, they're a magnesium alloy and lots of people are still driving around on them.

 

The Alpina wheel centers were made for racing so, yes, I would guess they might not have been made for longevity. 

 

You find me a 4th one and I'll be the guinea pig. ?

 

[mccusername]

2 hours ago, markmac said:

You might be able to recoup some of your cost by casting a few sets and then selling them off. 

 

There seem to be a fair number of people making re-pops of the earlier Alpina wheel centers, the ones where every other spoke is solid.

 

This place in England makes reproductions of the newer type wheel center-- and they make them in magnesium, which is pretty damn cool. Only 5-lug for e9s though.

 

https://www.cckhistoric.com/alpina-wheel-centres-group-2-bmw-csl/

 

 

 

[mccusername]

@markmac Pictures....

[markmac]

Interesting, your 100% sure they are 14"?  I had thought you could use the 13" centers that have every other spoke filled with certain barrels to make a 14" rim.  I always thought that is how the made up the 14" wheels.  A new one on me but why not.  If in fact it is 14", you will be making that part if you want to have four - the odds of finding a 4th would be (very) slim I would think.  I would probably take them to someone and have them vapor blasted then crack checked.  Then figure out a path forward.  Honestly that shape could be sand cast pretty easily, you would have some machining to do but pretty minor - I would cast it in a high strength aluminum.  Cool beans regardless.?

[mccusername]

Yep they are 14.25" diameter, just like Rey's in the original post. I wonder if he had a full set and if he ever built them up?

 

Can you see anything in the surface corrosion that leads you to think magnesium vs aluminum? I can't really tell if it's just gunky paint or what. As you said, I need to have them cleaned... but then they are not as good as wall art.

 

[markmac]

Oky doky.  Shame on me for not reading the original 2o1o post more closely.  Unlike yours that are clearly originals, Rey's look similar to those one's that CCK is re-casting, with fresh machining.  If at all possible find out where he found his and see if you can find another.  I am guessing someone is/was making them.  Raw magnesium changes from gold to grey as it is exposed to air/moisture.  Magnesium + moisture = badbadbadbadbad.  It's why it (magnesium) gets coated, then usually painted.  This is what raw, freshly cast magnesium looks like (or can look like), they often used a Dow 7or Iridite 15 conversion process ( I spent wayyyyy toooo muccccch time researching this for refinishing my Schnitzer engine covers.  The reality is that they only look this way once, when they are fresh out of moulds/machining.  They start to age immediately (sorry TMI)......

Edited January 27, 2021 by markmac

[mccusername]

No shame at all! I appreciate your experience and nerdy knowledge! I was trying to find information on what magnesium alloy Alpina used at that point, but no luck. In the early 70s it wouldn't have been pure magnesium anymore I'm pretty sure. But maybe since they were for racing, they have a higher magnesium content than, say, Campagnolos? 

 

One of mine has a chip in the edge. I wonder if magnesium alloy would chip differently than aluminum alloy?

 

There is a guy on e9coupe.com who is reproducing basically any Alpina or BBS wheel center. They are 600 euro each-- in aluminum-- and it seems you have to buy 4 at once. Let's just say that's a lot more than I paid for mine.

 

 

 

 

[markmac]

Aluminum or mag, that damage is repairable.  These guys can do it for you, and likely strip them down and crack test what you have.  You might reach out to Forrest at Kooglewerks, he has been a Covid casting madman, he has re-made Hardy & Beck centers in 13" (I think those were CNC'd though), Limmer (bbs esque) centers...and other stuff, seems to have really figured out the casting thing.

 

http://alfapartscatalog.com/NORMAN_RACING_GROUP.html