"Andrew B. Lundgren" wrote:
> >I don't know why Rick considers ALL the oil pressure gauges useless. Mine
> >provides what appear to be perfectly reasonable and consistent readings,
> >with numbers that correspond very well to what one would expect, again given
> >the known history of the engine.
Sorry for the confusion Andrew. Perhaps my note was penned at
the end of a stressful day and the words were poorly chosen expressing
my frustration rather than my true opinion. I apologize for that.
I don't consider the Smiths gauges 'useless'. I simply wanted to
emphasize that they are not precision instruments. Rather, they are
"indicators." Some are probably spot-on while others are off by a
mile! If +/- 10psi is acceptable <midscale> precision, then they are
fine. And I would argue that +/- 10psi is perfectly acceptable precision
because 98% of the time, all the gauge tells us is "all is okay" or
"Houston, we have a problem."
I suspect that the mechanical gauge is more precise than the electric
gauge but that's just my bias. The electric gauge is also a thermal
mechanism that is, by design, s_l_o_w to respond to changes. That, I
don't like because oil starvation causes damage quickly and possibly
quicker than a thermal gauge can warn the driver. Perhaps I am spoiled.
In my other sports car, the oil pressure gauge has very little 'damping'
and responds almost instantly to changes in pressure. That car also
performs comfortably at 7700rpm and would 'eat it's own lunch' if it
lost oil circulation and the driver didn't notice it VERY quickly. It also
maintains 100psi -- at idle. The precision of that VDO gauge in that car
is as poor as the MG's but serves the same basically binary purpose:
'everything is okay' or 'we have a problem'. It simply is not damped
and responds quickly.
So why do they build gauges that are heavily damped? Because most
of us don't like to see the instrument hands swinging around on the
face of the gauges! It is unnerving to see the oil pressure gauge move
around. Yet, that is exactly the information we NEED to see if we want
more than a GOOD / BAD indicator.
Have I communicated my original thoughts, this time without
overemphasizing the opinion -- and without 'flames'?
Best regards,
--
Rick Lindsay
Diamond Geoscience Research
5727 S. Lewis Ave., Tulsa, OK
Voice: +1 918-747-3456
Fax: +1 918-747-8599
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