-----Original Message-----
From: Ray McCrary <spook01@mindspring.com>
To: Kai Radicke <mowogmg@pil.net>; MG List <mgs@autox.team.net>
Date: Thursday, December 25, 1997 06:00 PM
Subject: Re: Magnafluxing a Head (price)
>Kai,
>It should be pretty cheap to have done.
>The process consists of affixing a large magnet to the head, after
>cleaning, and sprinkling a special powder onto the area to be checked. The
>powder is then shaken off; it falls away from all areas except in the
>cracks, where it stays, revealing the defect.
>Here in Nashville, you can have a head checked for $10, but I'm sure that
>prices vary..
>Ray
>
Well, as far as alternatives go, here are a couple. I don't know how many
of these are used for cylinder heads--we used them to check metal parts in
nuclear reactors, but the technology is pretty simple.
1) Radiographic-Basically taking an X-ray of the part. Effective, but
expensive and can be dangerous. Also difficult to test on an installed part
(no problem for heads, though)
2) Dye penetrant- A dye is wiped on to the surface, and then wiped off.
Cracks show up as bright lines where the dye wasn't removed.
3) Sonic Testing-Kind of like a sonogram, but requires great skill to
interpret the readings correctly.
4) Particle test- I -think- this is what is commonly referred to a
"magnafluxing", but not sure. Iron filings are sprinkled on the part after
is has been exposed to a magnetic flux, and cracks show up as concentrations
of filings.
Again, I don't know if any of these are common alternatives to the tests the
machine shops routinely do. I kind of doubt it, but the other methods ARE
out there.
Scott Gardner
gardner7@pilot.infi.net
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