Willie,
This is a bit academic for me, since my +4 hasn't been fired up for years
(it has to wait until I get around to restoring it), but the measurements
you had done interest me anyway. You say that you had the "water
temperature measured ... with a Raytek infrared gun." Unless the sensor
actually "saw" the water (in which case I have no argument, but wonder about
the actual setup), would the sensor not have measured the surface
temperature at the two locations? If so, the temperature drop across the
thickness of the walls has to be taken into consideration and a 10 - 14 C
drop may well be possible (depending, of course, on the ambient
temperature). The actual water temperature may therefore well have been
higher than what was measured. I would think that, to check the calibration
of the VDO gauge, one would have to place thermocouples at the same
locations as the VDO sensors and compare the readings.
Am I missing something?
Chuck Vandergraaf
'52 +4
Pinawa, MB
> ----------
> From: William G. Lamb, III[SMTP:lambroving@worldnet.att.net]
> Reply To: William G. Lamb, III
> Sent: Thursday, September 23, 1999 5:30 PM
> To: Stein, Ross; Lorne Goldman
> Cc: William C.W. Lamb; Morgan Mailing List
> Subject: Re: Cooling
>
>
> Ross, et al.
>
> To satisfy myself as to the accuracy of the VDO water temperature gauge
> in my 4.0 Plus 8, I had the water temperature measured at the top and
> bottom
> of the radiator near the location of both sensors, i.e. that for the fan,
> and that
> for the gauge, with a Raytek infrared gun. The fan kicks in for a few
> seconds
> whenever the gauge reads ~ 99 - 102 C. The actual water temp at the return
> elbow is 93 C. +/- 1. At the same time, the temperature at the top of the
> radiator is ~ 88 C. So... the VDO is most likely reading 12 - 14 C higher
> than actual water temperature. I know this info will come as a relief to
> many
> of you. It may also apply to owners of 3.9's since I believe the
> thermostat
> housings are the same, but you will need to check the VDO part numbers
> for the 3.9 and 4.0 to see if they are the same.
>
> Regards,
>
> Willie
>
> Land Rover Specialist
> NAS 4.0 Litre Plus 8 (R-11953)
> MSCC # 9096, Morgan 3/4 Owners Group
>
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