2.7L - How much magnesium?

flash951 · 03-30-2011, 12:28 PM

I have the 2.7L - 1975 engine.

How many % magnesium?
Is it cast aluminum magnesium?

Someone knows the answer out there?

RWebb · RWebb's Garage

you want the composition of the alloy?

it has been posted for the Fuchs wheels - not sure re the case

if that is what you want, try a search on alloy + case + 2.7 +mg + magnesium

you may have to look in Frere's book or Aichele's engine book

James Brown · James Brown's Garage

Let's just say a 2.7 is magnesium as compared to the 3.0 that aluminum.

Targalid · 03-30-2011, 04:03 PM

I a thinking that Remi is the guy who cracked off the corner of his engine case where the oil pressure sender is located. He is trying to find the right alloy for a TIG weld to get the hole filled. Am I right Remi?

James Brown · James Brown's Garage

Oh yes I remember now.

flash951 · 03-31-2011, 12:50 AM

Correct: Want to repair with HTS-2000

ANSWER:

Hello Remi,

If it is over 65% magnesium like some chain saw covers then no, however if it is cast aluminum magnesium which most parts on a vehicle are then yes.

You can see more information, testimonials, a video or place your order at Aluminum Welding - Aluminum Repair - Aluminum Brazing - AluminumRepair.com

Sincerely,

Robert
New Technology Products

sc_rufctr · 03-31-2011, 01:26 AM

I vaguely remember the later air cooled VW cases were about 40% Magnesium but that depends on what year.

It may be the same for a Porsche case but I'd be guessing.

BTW: Those VW cases would burn like crazy of you got them hot enough

Targalid · 03-31-2011, 06:38 AM

Remi,
You should be able to get a small sample to an analyticaL lab for testing. Around here, a sample can be tested for about $60 for four or five elements using spectral methods, AA or ICP. That would give you a certain answer as to the composition of your case. With all the oil business in your country there must be many such testing laboratories. Probably the correct information is archived somewhere though it might require a trip to a good technical library. Lesen sie deutsche? I am curious as I have a 2.7 which is likely made of the same alloy though I haven't broken any pieces, yet.
Al

flash951 · 03-31-2011, 06:43 AM

You have information in german?

Targalid · 03-31-2011, 08:47 AM

Nein! But I bet the engineering library at one of the local universities has that information. Another option would be to ask the professor of metallurgical engineering at that institution how/where to find the data. These guys love real world questions.

Flieger · Flieger's Garage

I think it is more like 90% Magnesium.

Jon B · 03-31-2011, 11:12 AM

The only two references I found for the magnesium alloy of 911 engine cases differ. Ludvigsen says AZ81 alloy was used when Mahle began engine case production; Paul Frere claims it was AZ91. The letters AZ refer to aluminum-zinc, the two main alloying elements; the numerals are the rough percentage content of each. Thus magnesium alloy AZ81 would have roughly 8% weight aluminum, 1% weight zinc, and AZ91 roughly 9% weight aluminum.

Targalid · 03-31-2011, 12:59 PM

Good job Jon! I looked up Ludvigsen and he lists two magnesium alloys used by Porsche, ZE41 and AZ81. The ZE41 was used in the early 60s in race cars. Production cars used the AZ81 magnesium alloy for engine castings. Here is a wikipedia reference for the alloys. Basically if Remi gets some filler for his TIG that is 90+% magnesium and 8% zinc he should be close enough to weld his case back together. Turn up the argon! Magnesium alloy - Wikipedia, the free encyclopedia

flash951 · 03-31-2011, 01:55 PM

Thank you. I need to look up an very experienced welding expert then.

Flieger · Flieger's Garage

I thought it ws ~90% Mg.

aws · 03-31-2011, 06:46 PM

The last time I had to weld up a mag case I sawed off a piece from a junk mag case and used it as filler rod. It worked fine.

aws

safe · safe's Garage

Quote:

Originally Posted by aws

The last time I had to weld up a mag case I sawed off a piece from a junk mag case and used it as filler rod. It worked fine.

aws

An old warped lower valve cover may work good and be cheap?

aws · 04-01-2011, 10:15 PM

Just be aware the early valve covers were aluminum and you need to use the mag case covers. If memory serves me right I cut off a piece of the flat area below the distributor hole... but I think any of the mag parts--chain housings, valve covers, vent cover, chain housing covers, would work.

aws