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Thermostat-To Be or Not to Be
Posted: Mon Feb 05, 2001 4:10 pm
by LuckyFloridaLin@aol.com
With this warm(hot) weather here in The Re PUB lic of Chad what say thou
about the use of thermostats,especially when it hits the 90's.That's not Snow
Birds.Can it be purchased locally or is it a Mother Moss ite? Tally Ho! Thom
Collins
Re: Thermostat-To Be or Not to Be
Posted: Mon Feb 05, 2001 4:33 pm
by JTPAKI@aol.com
Thom,
I ran without a thermostat during last summer. All it does is make the
engine running temperature vary by driving conditions. The flow will be
dictated by the water pump, so I don't think it helps to remove it. Also,
the standard thermostat has an inner shield that moves up and down with the
thermostat that operates the bypass opening. If you have that open and
unregulated, you will short circuit a portion of the flow to the radiator
which would make the situation even worse. I now have the modern thermostat
replacement in place with a limited opening in the bypass and I run without
water and antifreeze, but with a replacement coolant that is synthetic. It
has no water.
Joe Potter
In a message dated 2/5/01 4:15:58 PM Pacific Standard Time,
LuckyFloridaLin@aol.com writes:
With this warm(hot) weather here in The Re PUB lic of Chad what say thou
about the use of thermostats,especially when it hits the 90's.That's not
Snow
Birds.Can it be purchased locally or is it a Mother Moss ite? Tally Ho!
Thom
Collins
Re: Thermostat-To Be or Not to Be
Posted: Mon Feb 05, 2001 4:59 pm
by Chip Old
On Mon, 5 Feb 2001,
LuckyFloridaLin@aol.com wrote to
mg-tabc@yahoogroups.com:
> With this warm(hot) weather here in The Re PUB lic of Chad what say
> thou about the use of thermostats,especially when it hits the
> 90's.That's not Snow Birds.Can it be purchased locally or is it a
> Mother Moss ite? Tally Ho! Thom Collins
Thom, repeat the following until it is etched indelibly into your memory:
"I MUST NEVER RUN WITHOUT A THERMOSTAT."
It doesn't matter what the ambient temperature is, you still need a
thermostat. Contrary to automotive folklore, the purpose of a thermostat
is NOT to give you heat out of your heater more quickly on cold days.
The purpose of a thermostat is to force the engine to warm up as quickly
as possible to the temperature where (1) combustion occurs most
efficiently, (2) oil flows freely and does not form sludge, and (3) parts
expand to the point where clearances are normalized.
Until the engine temperature reaches that point, unburned fuel washes down
the cylinder walls, oil doesn't flow readily between the things it is
supposed to lubricate, and larger than normal clearances between
unexpanded cold parts allows them to hammer each other. This all spells
wear with a capital "W". The amount of wear that occurs before an engine
reaches normal operating temperature is MUCH greater than the wear that
occurs after normal operating temperature is reached. This in spite of
the fact that the amount of time an engine spends running at sub-normal
temperatures is normally an insignificant percentage of its total running
time.
The bottom line is, you want the engine to warm up to normal operating
temperature as quickly as possible.
The catch is, you also don't want the engine to overheat. A lot of owners
remove the thermostat in an attempt to make the engine run cooler. This
rarely helps, because once the engine is at normal temperature or above,
the thermostat is wide open anyway. The XPAG/XPEG engine doesn't normally
overheat as long as everything is adjusted correctly (especially mixture &
timing) and the cooling system is in good shape. If the engine overheats,
it's more productive to find the cause of the overheating and fix it.
If you don't have a thermostat, then one of the reproduction housings
designed to accept a modern thermostat is probably your only choice. As
far as I know, the original type is not available from any source. I'll
leave it to others to haggle over whether you should or should not
restrict the bypass when a modern thermostat is used. That tends to take
on almost religious overtones, so I'll stay out of it.
--
Chip Old 1948 M.G. TC TC6710 XPAG7430 NEMGTR #2271
Cub Hill, Maryland 1962 Triumph TR4 CT3154LO CT3479E
fold@bcpl.net