thafox

a friend of mine tld me about this trick if u will an i got to thinkin it sounds solid since the thermostat opens when the engine is hot and removing it would let only cold fluid to pass through....i'd like to hear your opinions on this 'trick'

Baldy

I'm pretty sure it would take forever for the engine to reach normal operating temperature. But I could be wrong.

ColinRX7

DON'T do that. The thermostat is there for a reason. You will create hotspots in the cooling system, and overcool other sections.



The thermostat is there to regulate the heat/cooling all over the system.



A new thermostat from Mazda is like $10 bucks.. No big deal!

Kathy Atkins

it's more than that, if you have no thermostat or the wrong one the water in the engine will never flow to the radiator, adn will keep circulating in the engine only, and more engine die every year due to cooling problems

1gendreemer

How does that work? It seems like when the thermostat is open (or not present) then coolant should route through the radiator...since that's when the sytem needs to be cooled. It doesn't seem to make sense. Also, why would not having a thermostat create hot/cold spots in the motor? If it were true, shouldn't the same thing happen then when the thermostat opens normally? I had heard of this "trick" before too and had concidered doing it. It just want to know the physics behind it being a bad idea.

mazdaspeed7

One, its a controlled restriction. One thing your friend forgot to mention was the restrictor plates used in place of the thermostat.



But thats still beside the point. A combustion engine operates best under certain conditions. One of those is coolant temp. The higher the coolant temp, the less heat is absorbed, and therefore less energy is lost as waste heat. An internal combustion engines thermal efficiency goes up as the engine temp goes up. But theres always a downside. Higher temps are more prone to detonation, and you also have to worry more about material limitations. The thermostat is there to keep the engine is the operating zone of the optimal balance.

rx7will

You should never take out the thermostat completely. You could run a thermostat the opens earlier or gut out the thermostat and just leave the plate in there as an restrictor.

jspecracer7

As The Queen stated....DO NOT TAKE OUT YOUR THERMOSTAT!



If you ever take apart the water pump housing, you will see how water flows thru the system. If you remove the thermostat, you will cause water to NOT go into the radiator. When the thermostat opens, it CLOSES the water bypass in the back of the housing...so by removing it, you will run most of the water thru the bypass and not the radiator.

Lynn E. Hanover

The stock thermostat operates as two valves where in other cars it is only one valve.



When the engine is cold the Mazda thermostat blocks flow to the radiator just as a conventional thermostat. However, the Mazda has a recirculation system that allows coolant to circulate around inside the engine during warmup, so as to keep the hot and cold side of the engine at about the same temps. Once close to operating temperature, the Mazda thermostat begins to close off a bypass loop with its foot valve and open the radiator loop with its more conventional looking upper valve. Once at operating temperature. The foot valve blocks all flow through the warmup circuit. and is regulating engine temps with its upper valve.



Without this system, for example, if you install a conventional thermostat and block off the bypass loop with a pipe plug, you get and over heated hot side and an Ice cold cool side (latent heat of evaporation) from fuel /air in the intake, every time you start the engine.



This stresses the whole engine and its sealing "O" rings, and shortens engine life.



Should you forget to block off the bypass port (below the thermostat) engine life will be limited to the first time you try it.



I run with the bypass port blocked and no thermostat most of the summer. In the fall when there may be a situation where OAT is too low to maintain 160 degrees of coolant temp, I install a conventional thermostat that has been modified with two 1/8" weep holes in the rim. So on warm up, there is some coolant flow to keep the hot side happy, and a full blast, a wide open thermostat.



I am looking for 160degree water and oil at full tilt. I seldom get it but that is the ideal. There is a 5/8" restricter down stream from the water outlet to keep pressure inside the engine higher than the rest of the coolant system. Also one oil cooler in the pressure side and two in the scavenge side. No overheats since 1980.



This is not a street modification. The picture is a race only system.



Lynn E. Hanover

howracer

nice post Lynn. (as usual)

thanks,



howard coleman