Thermostat-To Be or Not to Be

[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

[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

[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