AnksTank
Backyard Mechanic
Full Throttle Hits Only!
Posts: 294
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Post by AnksTank on Jan 27, 2011 13:43:59 GMT -5
less restriction = more flow = less cooling... the more time fluid stays in the block the more heat it will carry to the rad but you have to find a balance between to much or to little time.. personally i think a gutted thermostat is a bad idea and not very efficient.. you need to have restriction. but every engine reacts to heat differently... you should test that before derby day. iv done plenty of trial and error on this topic. best results were with after market thermostats that are temp sensitive. just my 2 cents
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Post by redneckron on Jan 27, 2011 15:15:09 GMT -5
whats? a thermostat
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Post by etownrdnck on Jan 27, 2011 15:18:39 GMT -5
its what regulates the amount of coolant that enters the engine
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Post by Engineerguy on Jan 27, 2011 16:31:41 GMT -5
I removed the center spring mechanism, or rather gutted it. The thermostat has a nice ring which is designed to seal the connection with the block. By gutting it, you get a tight seal and guaranteed flow, but a restricted flow. Too much flow and the heat will not transfer to the coolant as efficiently, causing the block to get hotter. Not enough flow and the coolant gets too hot and we all know what that looks like.
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AnksTank
Backyard Mechanic
Full Throttle Hits Only!
Posts: 294
|
Post by AnksTank on Feb 15, 2011 15:11:41 GMT -5
the more pressure a liquid is under, the higher its boiling point. This is precisely why cooling systems are pressurized. In the case of water, our most efficient coolant, we all know that at atmospheric pressure it boils at 100°C or 212° F. However, if we pressurize the water, its boiling point increases as follows: Pressure (PSI) Boiling Point (° F) 0 PSI-212° F 10 PSI-239° F 20 PSI-259° F 30 PSI-273° F 40 PSI-286° F 50 PSI-297° F
just some food for thought...
The thermostat is the "brains" of the cooling system and could be calibrated to application Years ago restrictors were popular for two reasons that do not hold true today. First, older radiator designs (large cross-sectional area copper tubes) were poor at promoting the necessary coolant turbulence in the radiator, so a restrictor was used to cause the coolant to begin tumbling as it exited the engine and entered the radiator. Secondly, with engines that had the thermostat located in the outlet of the engine combined with down-flow radiators that had a fairly low pressure radiator cap on the high pressure inlet side, if the thermostat was removed the increased pressure seen by the cap from the water pump could cause the cap's rating to be exceeded and the valve to open and purge coolant. Since this opening of the rad cap is what regulates system pressure, it meant that the overall system pressure would now be lower - the cap would open sooner than if the thermostat were in place holding backpressure in the cylinder head. Since system pressure was now lower, coolant vapour point was lower, and therefore the coolant's ability to effectively carry-off heat from the engine at higher temps reduced. This in turn would result in eventual overheating. Many folks erroneously assumed that the overheating was due to the coolant flowing through the radiator too quickly with the thermostat removed, that it didn't have time to cool in the rad. As a result, restrictors were used to "slow the flow of the coolant" and the car stopped overheating. Unfortunately, these folks didn't understand the real cause and effect of the overheating that they experienced after removing the thermostat, and this led to two enduring myths that persist today.
What was really happening was that the removal of the thermostat didn't cause the coolant to flow too fast to cool (we know this is an impossibility), but rather caused a condition where either system pressure (and therefore coolant vapour point) was lowered or where the rad purged coolant which caused the car to overheat. The end result was the same - the car overheated - but the cause and effect were confused and so the myths that a) removing a thermostat can cause a car to overheat and b) coolant can be pumped too fast through a radiator to cool properly began. Neither of these are true.
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Post by 82 on Feb 15, 2011 20:26:24 GMT -5
Sounds like good information, I'll keep running my 25lb caps.
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