Is this mechanical fan or electric? If electric then it is normal for the
fan to cycle on and off with the temp gauge moving between 1/3rd and 1/2 the
way between N and H at idle. Even if mechanical then in warm ambients like
the high 70s it will be normal for the gauge to get well towards 1/2 way
from N to H in a long idle. However when running in free air (i.e. not
crawling along behind a truck) it should be close to N in both cases.
First thing is have you measured the actual temperature of the coolant when
the gauge is reading high? If that is also high it could be because some
issue with the engine is producing more heat than the cooling system can get
rid of, or some problem with the cooling system is preventing it getting rid
of as much heat as it should. Simple causes of the first are things like
weak mixture, retarded or over advanced timing. The second could be
thermostat not fully opening (try running it without to see) or other
blockages, anything causing reduced flow *should* result in the bottom or
outlet of the rad being cool. Also check for cool areas of the rad
signifying blocked tubes, which can make the outlet very hot. If the rad is
very hot all over including the outlet then it points to the former problem
i.e. too much heat being generated.
As long as you empty and fill with the heater valve open the system should
be self-purging, just one or two heat/cool cycles should be enough to get
any air out of the system. I don't think I've ever got anything out of a
block drain. The heater is irrelevant in engine cooling - except that it
can supply *additional* cooling under extreme conditions. Whilst it seems
normal for HS carbs to gradually drop rpms in a long idle HIFs don't seem to
suffer. A strong fuel smell is not right, are the float chambers
overflowing? Similarly a strong fuel smell and vapour lock are mutually
exclusive. Vapour lock is virtually impossible, except with HS carbs where
it can occur in the jet pipes if the heat shields are damaged or missing.
Anywhere else the fuel would have to evaporate at the rate of more than one
pint per minute to cause fuel starvation.
PaulH.
----- Original Message -----
> Anyway, the new radiator is installed with new cap, hoses, clamps and
> thermostat. If now runs hotter than when the old radiator was in the
car...
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