> Incidentally, don't let anyone talk you into "welding" the head. (Been
> there, done that.) The head, cast iron, does not like to be welded.
> You first must preheat the head in an oven (industrial), then "v" out
> the crack (if you can see it) and then weld it with a special arc
> welder and rods. (Not for the weekend mechanic or faint of heart)
> Odds have it that you'll probably crack the head worse than it was.
I have heard of a "Cold-Stitching" process that is reputed to work
well and can be applied suitably in the majority of head-crack situations.
Does anyone know about this?
Presumably, the process involves no more sophisticated equipment than
a decent drill-press but is somewhat labor intensive. To stitch the head,
the head must first be magnifluxed for cracks and clearly marked. A hole
is drilled at the location of the crack, tapped, and a plug of sorts is
threaded into the hole. The plug is ground down to the approximate surface
and another hole is drilled overlapping the plug and at a slightly different
angle. The process repeated over and over again throughout the length of the
crack. Oh yes, it also involves inserting some substance (magic fluid ?)
into the tapped hole to facilitate bonding and eliminate any voids at the
blind end.
I've been tempted to try this myself if it has reasonable hope of reviving
cracked heads.
-Steve-
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