[Spits] Gauge photo

[Richard Gosling]

Daffy (my Spit) passed away several years ago, but as far as I remember my
gauge tended to read at or just over 1/2 once warmed up, and would go up to
about 3/4 in stop/start traffic on a warm day, so this level of reading
wouldn't unduly worry me on it's own.  I'd be wary of putting too exact a
number on the gauge positions, I suspect both sensors and guages vary
somewhat from one to the next, so they won't be consistent.  Only way to
know for sure what temperature it is at is to remove the radiator cap
(carefully!) when hot and stick in a thermometer, or use one of those fancy
infra-red temperature sensor thingys.

Unless it's faulty, your thermostat will have opened long before your engine
gets to the temperature shown, whether it's a standard or low temperature
'stat.

One question - how's your fuel gauge behaving?  If it's over-reading (beyond
'full' when just topped up) then your engine isn't overheating at all, both
gauges are over-reading because your voltage regulator has packed in.

I'd also be tempted to try running one of those radiator flush products
through the engine, there's likely several decades of crud that could be
blocking the passageways and impeding proper coolant flow.

But I'm still not convinved that your poor running problem is caused by
overheating, or at least not only by overheating...

Richard




On 22 July 2010 00:51, Greg Stull <gastul at roadrunner.com> wrote:

>  Here the picture of the gauge. Don't go through on the list.
>
> ----- Original Message -----
> *From:* Richard Gosling <rbgosling at googlemail.com>
> *To:* Greg Stull <gastul at roadrunner.com>
> *Cc:* Spitfire Group <spitfires at autox.team.net>
> *Sent:* Wednesday, July 21, 2010 8:06 AM
> *Subject:* Re: [Spits] Sputtering when hot above 50 mph
>
>  "I'm going to put a 160 degree thermostat in to see if that helps...."
>
>
>
> You cannot fix an overheating problem by using a lower temperature
> thermostat (unless the existing 'stat was faulty and failing to open, in
> which case a new standard temperature 'stat would work just as well).  If
> your coolant is at 240deg, it makes no difference what 'stat you've got in
> there, a 180deg 'stat will be just as open as a 160deg 'stat.
>
> All that a lower temperature 'stat will do is open when the coolant reaches
> 160deg, delaying the engine getting to it's optimum operating temperature
> (more like 200deg), and allowing the engine to run cooler than optimum if
> conditions allow (i.e. travelling at reasonable constant speed with little
> load on the engine).  If your engine has got a problem and wants to run hot,
> it'll reach that temperature regardless of what thermostat is fitted.
>
> Richard