1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

?Why run a Thermostat?

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Old Jan 12, 2005 | 04:53 PM
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?Why run a Thermostat?

I live in FL so I dont have to worry about a cold engine! I am rebuilding my engine and my thermostat housing is already pluged, so why should I go back to a thermostat? Just so my engine warms up faster? If that is the only reason, then Iam leaving it out.

Opinions?
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Old Jan 12, 2005 | 05:00 PM
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I've wondered about that myself in warm climats.

I don't really know the answer, But I'd have one anyway, It's not like they're expensive and they don't hurt performance.......


why not warm up faster and stay in an optimum temp range? I don't know about you but my car runs like **** until it's up to temp.
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Old Jan 12, 2005 | 05:02 PM
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i gutted my t-stat so there is one less thing to rule out when tracking down overheating gremlins.
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Old Jan 12, 2005 | 05:05 PM
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When the engine is cold, it will wear faster. The sooner it reaches operating temperature the better - there is no advantage to removing the thermostat. If you're worried about it jamming closed through failure, you can get failsafe thermostats that remain in the open position.
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Old Jan 12, 2005 | 05:11 PM
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not bad running w/o one either though..
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Old Jan 12, 2005 | 05:17 PM
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Originally Posted by d0 Luck
not bad running w/o one either though..
Guess you're a fan of higher fuel consumption and increased engine wear then.
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Old Jan 12, 2005 | 05:51 PM
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Isn't there a problem with flooding in 7's due to engines not heating up properly? Or is this not a problem for 1st gens?
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Old Jan 12, 2005 | 06:23 PM
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Originally Posted by Jon_Valjean
Guess you're a fan of higher fuel consumption and increased engine wear then.

why get a rotary if you cant handle the bad mileage.
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Old Jan 12, 2005 | 08:19 PM
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http://auto.howstuffworks.com/question248.htm
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Old Jan 12, 2005 | 08:26 PM
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You need at least the guts of it to slow down the coolant. If the coolant moves too fast it cant pickup heat efficiently. Its important.
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Old Jan 12, 2005 | 08:26 PM
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A thermostat doesnt just open when the water gets hot.It regulates the coolant flow through the engine,not only to keep the engine at a constant temp,but as a restriction it slows the coolant's passage through the radiator,giving it time to shed heat into the radiator fins.If you just take it out,the engine will take longer to warm up(which increases wear and fuel comsumption) and it could over heat when pushed on a hot day.

Gutting the thermostat and leaving the baseplate in will provide the needed coolant restriction,but you must be sure to block off the bypass hole below the thermostat or the coolant will just recirc back into the engine.

Thermostats are cheap and accesible.And if you change your coolant regularly like you should,theres no reason you cant easily pop a new Mazda one in every 2-3 years to prevent a failure.

(its a tie Carl....6:26PM,heh,heh)
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Old Jan 12, 2005 | 09:16 PM
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Originally Posted by steve84GS TII
A thermostat doesnt just open when the water gets hot.It regulates the coolant flow through the engine,not only to keep the engine at a constant temp,but as a restriction it slows the coolant's passage through the radiator,giving it time to shed heat into the radiator fins.If you just take it out,the engine will take longer to warm up(which increases wear and fuel comsumption) and it could over heat when pushed on a hot day.

Gutting the thermostat and leaving the baseplate in will provide the needed coolant restriction,but you must be sure to block off the bypass hole below the thermostat or the coolant will just recirc back into the engine.

Thermostats are cheap and accesible.And if you change your coolant regularly like you should,theres no reason you cant easily pop a new Mazda one in every 2-3 years to prevent a failure.

(its a tie Carl....6:26PM,heh,heh)
This is a perfect example of the right answer for the wrong reasons. The radiator doesn't care how fast the water is flowing. Actually the radiator likes it as fast as possible. The faster the water moves the more heat it will flow. (infinite water speed can transfer an infinite amount of energy at zero temperature difference)

But there is a problem with the water flowing too fast. Cavitation. It starts in the water pump. Cavitation causes water vapor bubbles in the in the coolant. The heat capacity of water vapor is hundreds of times lower than water. It also ruins the efficiency of the water pump impeller.

Mazda recommends both keeping a thermostst restriction and slowing the water pump down in a racecar to keep the water pump below the cavitation level.

You can probably get away with no thermostat on the street but if you spend any significant amount of time at high RPM, you'll probbably have problems.

ed
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Old Jan 12, 2005 | 09:17 PM
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LOL, well Im glad you were in more of a typing mood than I am.

Last edited by Rx7carl; Jan 12, 2005 at 09:20 PM.
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Old Jan 12, 2005 | 09:56 PM
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i always thought that if there was no thermostat and restriction the radiator couldn't cool the water enough before it goes back through the hot engine. since not being able to cool the engine cause the radiator couldn't cool the water.
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Old Jan 12, 2005 | 10:50 PM
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no thermostat will make the engine run too cold!!!! and not run properly! also if it des start to heat up the coolent will be moving too fast pto transfer heat and therefore creating a greater risk for over heating. TRUST ME I JUST AD TO DEAL WITH THIS!

My thermostat broke and stopped opening. So i pulled it out. While driving it ran really cold and ran like **** when I got into trffic it got really warm didn't over heat, but it was well beyond regular opperating temp!
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Old Jan 13, 2005 | 12:41 AM
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t-stat

The t-stat allows a cold vehicle to come up to operating temp faster.this means that the heater will work in winter. Think of it as a heart valve, when you are at
low demand your heart pumps out a certain volume, but when you start running or excersizing she pops open and gives you the proper amount of lfow. Same theory in engines. While you are driving the heat is being exchanged by the raditor
ram air flow to cool the system down.under a load or in stop and go situations you need to make sure that the water coming in is being regulated long enough for the radiator to cool it down. REmember the hotter a engine runs without overheating the more fuel efficent it is, During cold weather without a t-stat means
no heater and you better have choke system to keep it running. In hot weather without a t-stat will lead to overheating. Their has to be enough time for the coolant to stay in the radiator to cool down before it goes thru the engine, If it cant do this, it will pick up more and more heat and create heat pockets which will
turn your engine into hot pocket sandwhiches, lol. rx7doctor
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Old Jan 13, 2005 | 12:53 AM
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Originally Posted by Jon_Valjean
Guess you're a fan of higher fuel consumption and increased engine wear then.
yes, that's why my motor has 139k on it and still get 20+mpg on street and a good 25+mpg on the highways.

weather is also factor here. if you live in place where it snows and summers are hot, then the t-stat is definitely needed for those exact reasons aformentioned by the doc, and others.

Last edited by d0 Luck; Jan 13, 2005 at 01:05 AM.
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Old Jan 13, 2005 | 01:16 AM
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I ran no thermostat in my 85 for the duration of time that I had it running... it overheated everyt time I had to do stop-and-go traffic that the French Quarter is notorious for. When I would run it down the highway, no stopping, the temp guage never got above 1/3 way up.... but in-town? The heater was on full blast, I was dumping ice into the radiator, and still, it overheated like a mothafucka.
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Old Jan 13, 2005 | 01:28 AM
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I know that this may not apply here, but I've had two cars overheat to the point of eating all the coolant (EEK!) when the thermostats died. Of course, these were boingers, but still. . ..
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Old Jan 13, 2005 | 08:22 AM
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I have run with out a tstat before and the only difference I have seen is a longer warm up, heater still worked, never got hot or too warm. Everything always ran good for me in traffic or not? My fiero fan was always kicking, so Iam not sure if homeboy that said he would over heat in traffic had a Efan or not?

I think I will stick with a tstat, it is not hard to install and doesnt cost much.
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Old Jan 13, 2005 | 12:56 PM
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a bit off topic, but do u guys still rely on the stock temp. gauge? or you guys hvae aftermarket temp. gauge to determine it's overheating?
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Old Jan 13, 2005 | 02:59 PM
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You can run with no thermostat but it is imperative that you block the bypass hole in the water pump housing like RX7Carl has mentioned. If you don't all your doing is recirculating hot water back into your motor. What's the purpose of not running a thermostat anyways if someone can justify taking it out and the advantages to it I would like to know.
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Old Jan 13, 2005 | 05:33 PM
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yea I have an e-fan my car has everything.. and i have both stock gauge and autometer
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Old Jan 13, 2005 | 05:41 PM
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Originally Posted by 13btnos
You can run with no thermostat but it is imperative that you block the bypass hole in the water pump housing like RX7Carl has mentioned. If you don't all your doing is recirculating hot water back into your motor. .
on a street car, there is no difference between "tapping" and "tapping" the water pump by-pass. I've tried them. Maybe for race but street, its a waste of time.

Personally, I always use gutted t-stat and I only warm up my car in the morning (just enough for me to finish my coffee and cigarette). Afterwork, its a different story as it just a "start and go." The old 13-B big street port with no warm up and daily abused lasted over 130,000 miles. Maybe it lasted long as I ran the 48 IDA rich. Yes, abused but maintained. In fact, when I took it apart to get it re-sealed, the rotor housings and such were still in good condition. That motor is in my RX-3 at this time.

just my $0.02.
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Old Jan 13, 2005 | 05:59 PM
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how about your 01 cent?
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