| Recently completed
testing by an independent testing facility with support from a leading bearing
manufacturer has confirmed what experts at SAE and McDonnell Douglas Transportation Dept.
have been saying for years. Most of the mechanical wear in an engine occurs during engine
start-up. Oil pressure's non-existent during the critical high stress, high torque, first
seconds of start-up. Two identical engines were
tested; one with a Pre-luber system, the other without, The Pre-luber equipped engine
showed less scuffing and up to 53% of the bearing wear was eliminated in the engine
equipped with the Pre-luber system.
Pre-luber Reduces Wear
Mechanical Wear - The removal of metal that occurs when
engine parts are temporarily devoid of lubrication and metal meets metal.
Studies by SAE and McDonnell Douglas indicate that the majority of this wear occurs
at start-up.
(Fig.1)
Bearing in motion (at left) shows oil separating
surface. The parts virtually ride on a thin film of oil. Bearing with engine
shut off (right) shows metal to metal contact.
Running Stop
Normal Preluber
Start
Start
(Fig. 2)
Polished bearing surface magnified approximately
10,000 times.
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In Fig. 2A oil
pressure forces the bearing apart, metal to metal contact cannot take place. However, when
an engine is shut off the film of oil collapses and metal to metal contact occurs. (Fig.
2B). When you next start the engine, you tear off the peaks of metal, which are
then.are carried away in the oil. (Fig. 2C).This is how a part is worn out. The
Pre-luber
system eliminates the metal to metal wear by automatically oil pressurizing the entire
engine before it is started. (Fig. 2D).
Abrasive Wear - Contamination of the oil causes abrasion which
results in scratching the bearing surfaces.
The contamination comes from three main sources: combustion by-products, atmospheric dust
and mechanical wear debris, (graphically depicted below).
Engine under normal operating condition.
Mechanical wear debris is virtually
eliminated in engines equipped with a Pre-Luber system.
The best way to prevent abrasive wear is to eliminate the
abrasives that cause the wear. Pre-luber eliminates the hard metal oxides produced by
mechanical wear, which reduces oil contamination and abrasive wear. |
