[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]

RE: [T3] Volkswagen Metallurgy 101


On 24 Nov 98, at 7:29, Erkson, Toby wrote:

> >-----Original Message-----
> >I had one just like this once.  It was broken here because the nuts 
> >on the main bearing studs (see other side of the case) had come loose 
> >and the crank had pushed the case halves apart, bending them and 
> >breaking the left side there.  If this is the story for you, I'm 
> >afraid that you're SOL.
> 
> Brian F. told me to check the head torques and they are nice-n-tight per
> Bentley.

Note that I wrote MAIN BEARING STUDS, not head studs.  The head studs 
are irrelevant to this failure.

> >I recommend that you NOT try to weld this.  The heat might well do 
> >something to the oil in the oil galley and cause worse problems.
> 
> I talked to three professional welders and they have no problem with welding
> the material and two of them had done air-cooled VW engines in the past (and
> have welded magnesium as well) and all were aware of the case makeup.  In my
> welding research I know it can be done.  I would need to remove, and
> partially disassemble, the engine and naturally this would involve draining
> the oil.

Of course there is no problem with welding the Magnesium alloy case.  
The problem is with the small amount of oil that will inevitably 
remain in the oil galley just under your crack.  Welding there will 
turn that to a hard crusty residue.  Have you heard of coking up a 
turbo?  This would be the same thing.  The stuff could either stuff 
up the passage, or crumble up and pass on to the cooler and stop that 
up, or get into the bearings.  None of these possibilities is 
reassuring.

Since you needn't be concerned about strength here, don't get carried 
away with trying to weld this.  If you remove the cause of the 
problem it will be fine with the easy solution; if the cause is 
allowed to persist even the weld will crack again.

I'm afraid that this problem is probably terminal (for the case), but 
you can do something now that will allow you to plan for your next 
step and take it slowly.

Jim
-
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
*******************************

-------------------------------------------------------------------
Unsubscribe? mailto:type3-request@vwtype3.org, Subject: unsubscribe


[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [New Search]