"Edgar" wrote in message
...

"Tony Helton" wrote in message
...
. Don't forget that frequent magnafluxing
of the block helps too.

You strip your engine on a regular basis just so you can magnaflux the
cylinder block??.



Edgar,

Magnafluxing is an old technique used to detect cracks. The method uses
magnetic fields to detect eddy currents and discontinuities in the flux
path. Using modern equipment but the same principles, one can easily detect
cracks with a flux gate magnetometer and no iron filings. Where ever there
is a crack the surface magnetic field of the metal increases and there is an
almost discontinuous gradient in the magnetic field. There are even paints
sensitive to magnetic fields and these would show cracks also. However, the
high temperature of the engine degrades the performance of magnetic
materials. I do not strip my block to magnaflux it, it only gets magnafluxed
during rebuild.

There are many acoustical techniques that can detect engine wear and are
used by industry. These methods were first developed by General Electric in
the 1950s for tooling machines.A simple high fidelity, wide bandwidth
acoustic recording of an engine operating will yield many details about the
condition of the engine. A spectral analysis of the audio signal can
indicate bearing wear, unbalances, mis-timing and the like. You can do this
all with a microphone and a PC with spectrum analyzer software.

Here are just a few examples:

http://adsabs.harvard.edu/abs/1999ASAJ..106L...1M

http://www.grandprix.com/ft/ft00345.html

http://www.kirkup.info/papers/engnoise.htm

http://www.atypon-link.com/BINT/doi/...i.2008.50.1.30



Great example with graphs:

http://www.medav.de/fileadmin/redakt...ne_testing.pdf

And applied to boats:

http://mole.imm.dtu.dk/aewatt/pubs.php


The advantage of the acoustical method over the oil analysis method is that
the acoustical method can be done all the time and catch problems way before
they turn into ground up metal. The method can also detect problems that may
never turn into ground up metal. Think of it this way: how effective is a
urine test in finding a broken arm? If you listen to the patient you may
find out more than with a urine test.

Please take what ever Jonathan rants about with a grain of salt. He has no
technical background to be knowledgeable on these matters and his anger
colours all of his responses. If he could only learn the patience necessary
to grasp technical things he wouldn't feel so helpless. Most assuredly,
Jonathan would never submit to a urine test, so he would most certainly
appreciate the benefits of the acoustical method.