~ Thanks again to all those who offered advice concerning my
~ overheating TR6; it undoubtedly seemed from your advice that the culprit
~ was a defective thermostat. UNFORTUNATELY, when I went to replace it this
~ past weekend I learned that the PO had decided that the car didn't need one
~ in the first place so I'm back to square one (except with a new summer
~ thermostat in place).
To begin, we discussed (in LABORIOUS detail, with 27 8 x 10 color glossies
with circles and arrows and lines on the back :-) the physics of coolant
flow last year, with the usual chorus of disagreeing Ph.D.s arguing over
minutiae. God, I love this list... :-)
One fact arose out of that discussion: Most cooling systems, Triumphs
in particular, rely on a thermostat to direct cooling flow correctly
through the cylinder head. That is, the little tube that sits below
the thermostat plate pushes a certain amount of coolant through a
side passage and then through the cylinder head. Triumphs in
particular don't like being run without a thermostat; it actually
makes them run hotter.
Two things to check for your extra heat:
- Timing. If you're running timing that's a little more advanced,
your engine will run warmer. Remember to do what your manual
says with respect to any vacuum advance/retard lines when you
hook up the timing light; that can make enough difference to
change your temperature.
- Fuel flow. Running lean runs hotter. If you recently had your
carburetors tunes (particularly as part of a smog test), you may
have had the mixture leaned out to such a point that you are
dumping more heat into the cooling system.
As a final comment, have you bled your cooling system to make sure
there isn't any air trapped in and reducing your volume? And what
ratio of glycol to water are you running? Use more water than
glycol to drop your temperature a little.
--Scott "Of course, you *might* have dead flies in the fins" Fisher
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