Magnesium fan-housing replacement

[adias]

I had to replace the alternator and found out that the original magnesium fan-housing was badly cracked.



Looking for a replacement I found the US-made EPS Al unit (weighing 11lbs) and a magnesium replica (weighing 2.73lb) made by CarPoint.



The german unit shipped from Germany in 3 days at a cost (including shipping) of about 60% of the EPS part. The fitting is perfect, both fitting the engine and cooling shroud, as well as fitting either the Valeo or OEM 90A alternator.

Carpoint sells in the USA on eBay. Link for the fan-housing HERE.


Note: I must credit member Discseven for his excellent advice and guidance in making this repair!

[Koizumi]

Where was this tip a few months back!!!

Good to know!

[lpsalsaman]

Wow glad you got it replaced, cause it would have been a catastrophic failure! Those cracks look really bad! I wish I would have found the German site you got yours, since I replaced mine years back with an aluminum one from Vertex. However, I can't complain much, it is a solid piece so I know it will be there for years to come. Anyway great work!

[LUFTKUL]

I found the Carrera 3.2 fan housing/shroud the hardest to find. I couldn't find an aluminum one at the time, but did find a new replacement magnesium unit. Happy to find it and it fits great.

I wasted a couple of days dragging my old housing around to welding shops to see if they would repair it. No one wanted anything to do with it. It's now wall art on my shelf.

[Jack Stands]

I understand that welding magnesium is a very specialized process, but can be done. I suspect most shops don't want to be bothered.

Was the housing dropped? I can't imagine there should be that much stress on that part as it only holds the ignition coil and fiberglass engine shroud attachments. I'd wonder if JB Weld would even suffice?

[mepstein]

Ben / MB911 welds alum, mag, steel, etc. he just fixed (rebuilt) the clutch cable bracket on my magnesium 915 trans. He has posts showing his welded and refinished fans and housings. He can fix the nicks on the fan for a fraction of new.

[mepstein]

Originally Posted by Jack Stands

I understand that welding magnesium is a very specialized process, but can be done. I suspect most shops don't want to be bothered.

Was the housing dropped? I can't imagine there should be that much stress on that part as it only holds the ignition coil and fiberglass engine shroud attachments. I'd wonder if JB Weld would even suffice?

Almost every Carrera fan housing I've ever seen is cracked - or will be soon. Impossible to find used.

[theiceman]

Originally Posted by adias

I had to replace the alternator and found out that the original magnesium fan-housing was badly cracked.



Looking for a replacement I found the US-made EPS Al unit (weighing 11lbs) and a magnesium replica (weighing 2.73lb) made by CarPoint.



The german unit shipped from Germany in 3 days at a cost (including shipping) of about 60% of the EPS part. The fitting is perfect, both fitting the engine and cooling shroud, as well as fitting either the Valeo or OEM 90A alternator.

Note: I must credit member Discseven for his excellent advice and guidance in making this repair!

what yea car is this off ?

[adias]

Originally Posted by theiceman

what yea car is this off ?

'86.

[Jack Stands]

👍 on Ben's talents! It's always good to find a true craftsman/artist.

[Koizumi]

I had my original welded by a great shop but it lasted a year. It is not worth welding repairs on this! It will fail and it's not a particularly pleasant job switching out the unit. Best to do it once, the right way, and be done with it.

It was a real pain finding a new unit. And it was not cheap either. Again, wish this info was available to me when I really needed it.

Cheers

[theiceman]

does that German supplier have SC versions also or are they backwards compatible ?
that look like a very nice piece .

[kuehl]

Just be sure the timing mark line etched on the new housing aligns with the split in the engine case.

[adias]

Originally Posted by theiceman

does that German supplier have SC versions also or are they backwards compatible ?
that look like a very nice piece .

On the link I provided above, CarPoint states:

[For:] Porsche 911 1978 - 1989 3,2 Carrera 3,3 Turbo

You may want to contact them and ask.

[adias]

Originally Posted by kuehl

Just be sure the timing mark line etched on the new housing aligns with the split in the engine case.

Yes, of course, all working correctly.

[Discseven]

Originally Posted by Koizumi

It is not worth welding repairs on this! It will fail and it's not a particularly pleasant job switching out the unit. Best to do it once, the right way, and be done with it.
Cheers

+1

Know fact that magnesium's stellar attribute is weight reduction. Cost for that is durability. Fractures in a fan housing can be beautifully repaired, but remainder of magnesium in that house is still age-stressed.

Nice find & share Tony. And compliments on clean powerplant!

[manbridge 74]

The main reason they crack is people think the housing should be torqued to something like 100 ft lbs. I forget the spec but it's not a lot. Once overtightened they tend to crack or warp.

[Plays with cars]

eBay ad states "$102 shipping". Ouch! Glad it's light. :-)

[adias]

Originally Posted by Plays with cars

eBay ad states "$102 shipping". Ouch! Glad it's light. :-)

Sure! But compare $540 to $950+ for the US Aluminum part...

[adias]

Originally Posted by manbridge 74

The main reason they crack is people think the housing should be torqued to something like 100 ft lbs. I forget the spec but it's not a lot. Once overtightened they tend to crack or warp.

Right! Bentley states 18lb ft.