[Mg-t] Cast Iron block lip broken

[Gene Gillam]

Mike,

I have had a couple of blocks rewelded - one was cracked where the starter
bolts up and on the other the starter mounting bracket had broken all the way
off (thank you UPS).  Both times the welder preheated the area and then welded
ithe didn't seem to have any problems at all.

I've seen a number of blocks where the external water channel (behind the
exhaust manifold) that had been repaired by brazing - if you don't want to
weld repair the area I would opt for this over JB weld.

Gene








On Mar 4, 2013, at 9:02 AM, PopeyMike at aol.com wrote:

> The oil pan lip on the engine block has one triangular piece broken in the
bolt area.
>
> Theoretically - the other bolts in the area will hold the pan in place and
it has never leaked there since the previous rebuilder put massive amounts of
Red- RTV on the gasket surfaces.
>
> I would like to repair this section - but am afraid of damaging the cast
block - anyone have experience doing this kind of work?
>
> My solutions are three:
>
> 1.    Weld in thsi area - but this requires masive amounts of preheat and
high local heat - so I have nixed this solution.
>
> 2.    Fill in with brazing rod & retap - Brazing material is softer and at
lower temps then welding - but still required high preheat and slow cooling -
being that this area is on an outside lip - I do not believe I will have much
to worry about shrinkage creating a crack - since the brazing material should
strech enough not to create undue stress on the cast iron.  The only problems
are the preheat and cooling adn the hardening of the cast iron.
>
> 3.    USE J-B Weld and reinforcing it with steel screen mesh and retapping -
Drill 1/16" holes by 1/8" deep into the flange area near the screw threads and
at the flange edge.  J-B Weld 1/16" steel rod into these areas to form the
bases of support and strength.  Then cut pieces of screen to fit and overlay
the outside portion of the lip in the area - then fill in with layers of J-B
Weld and screen misture.  After retapping - install a helicoil for the
durability of the therads.
>
> This area does not need to be supper strong or super stressed under a high
torque value - the pan is very rigid and the purpose is only to screw in a
bolt to hold the gasket in place somehat tight.
>
> Has anyone had to make such a repair?  Is J-B Weld a good strong resin to
use with cast iron? or is there a better resin?
>
> Or just leave it alone?
>
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> Michael Balahutrak
> 53 - TD