Gentlemen:
Further to this - a couple of years ago, when the sleeved thermostat issue
was the current hot topic on this list, (there should be lots of stuff in
the archives on this!) a couple of us here bought about 20 or so 180
Robertshaws, and a few 195's, after learning that BCS supplied only 160's,
which are too cold for most of us. Sleeves were made up and mounted, and
several were installed in various different Healeys (and one hot running
MGB) and tested. (I'll check and see if there are any left, Alan)
Results - the sleeved thermostats helped, but only a little. In the
BCS/Robertshaw system, the sleeve ring moves downward as the thermostat
opens, and because of space limitations, does not fully cover the bypass
hole even when the 'stat is fully opened. The original Smiths 'stat moves
upwards as the thermostat opens, and the sleeve ring is considerably wider
and is much more effective at blocking the bypass hole.
Some tests were done on the stove top in a pot of boiling water - measuring
the total travel of the sleeve ring from closed to open - we had an OEM
Smiths unit to measure as well. The conclusion after all this was that the
Smiths unit might help a bit more, and that we wished that someone would
reproduce them in the future.
The whole Robertshaw 'thing' may be a mute point now - I have heard recently
that the company has stopped making them.
One other thought, touched on by Michael - we may be making a bit too much
of the cooling issue on our Healeys. After the '02 Tahoe meet, my wife and
I headed eastward across Nevada on Hwy 50 - Aspen, CO was our destination.
The temp that day was 105 - 110 degrees, the road quite flat.
We were in the tri-carb, the cooling system is bone stock - original
radiator, air deflectors, fan blades etc. The car was in a normal correct
state of tune, according to the book, mixtures set at sea level, so ever so
slightly rich at altitude. The temp gauge indicated 200 - 220 degrees
steady all day at 65 - 70 MPH. We were in the company of two other
Healeys - both drivers indicated similar coolant temperatures on their
gauges. None of the cars missed a beat or were the worse for wear, all ran
with good power all day. I'm sure that other Healey owners can tell similar
stories travelling to and from various meets in hot weather.
Earl Kagna
Victoria, B.C.
BT7 tri-carb
BJ8
|