[urq] 2-Piece Manifold

[Eric J. Fluhr]

>Welding cast is more an art than science I think, I've had some success 
>with the audi manifolds,
>my wx motor has a welded one piece...excavate the crack and drill the ends 
>and find a guy that
>can do it....my last attempt to repair a 3.0 mercruiser block proved 
>unsuccessful with welding,
>two different guys tried, however the freeze induced block crack was 
>successfully repaired with JB weld.

All of my research on welding cast iron says that you should thoroughly 
preheat the entire piece to a
uniform temp between 500 and 1000 degrees.   Also, weld in small increments 
to avoid building significant
thermal hot spots in the cast iron, since it does not handle localized 
temperature differential well (i.e. it tends
to crack more).   The welding rod is also important for a successful 
result...I think nickel rod is the
generally accepted material.

Regards,
Eric
'82 urq