GWW

A radiator shop by me stated. "In 50 years he couldn't remember ever seeing an engine run hotter with no thermostat."
So I took mine out on a 103 degree day and it made no difference. My neighbor stated he has had an engine boil over with no thermostat. The myth is does the water move to fast through the system to cool with the stat out?
Busted?
Plausible?
Confirmed?
GW

5678TA

the water must be able to stay in the radiator for a bit to properly cool.. thats what the fins on the radiator are for.. so yes, without a thermostat the water does move a tad too quickly.. when it moves too quickly, the radiator doesnt get enough time to cool the water and therefore, some people's motor will run hotter..

thats what i think

Sonix

iTrader: (1)

Yea, that's the theory at least, it moves too fast to cool. Unfortunately it dies off at theory

As your mechanic, yourself, and myself can confirm - it's a myth. I've certainly never seen it happen either. When my t-stat stuck open on both my cars, it ran super cold, and never warmed up. When a buddy removed his t-stat, it was a very cold winter for the next owner....

GWW

Maybe it's the Fresno weather 100+ most of the summer but with the stat out my car warms up normally and runs at the same temp regardless, about 225-230d. Winter yes it never warms up with the stat out or too cold a stat. Honestly I'm leaning towards plausible but there has to be special circumstances.

F-Body Demon

iTrader: (1)

Id say its abit of both, smokey yunick did say that he ran without thermostats in his cars. HOWEVER he did put washers in as "Restrictors" to slow the flow.

Apeiron

A lot of people think they've seen that, always on downflow radiators. You figure out the connection.

jaredi

IIRC the insertion of washers in place of the T-Stat was to slow the flow to stop it from cavitating at certain areas of the block. The fear is that some areas the coolant is prone to cavitate and create a hot spot on the block.

Apeiron

Sort of... the restrictor is supposed to allow some pressure to be built up in the block to discourage steam pockets from forming.
----------
If that was true, then by the same token the water wouldn't be spending enough time in the block to get hot either.

2tonedmaro89

go post it on discovery.com....they say to go on there if you have any myths for them

jaredi

Thats the ticket! Steam pockets thats what I was trying to remember. It seems to me though that when the system got up to temp and pressurized it would build up all the pressure it needed.



Thats the same idea that one guy had when he said "Think of holding a torch on a copper water pipe, when the water is flowing faster it doesn't have time to heat up." But the idea is not to heat up the water, it is to cool down the pipe (block).

bntyhntr00

For the most part the thermostat is not going to do anything that would make the engine run hotter. It will however not allow the motor to reach operating temp as quickly as it should- because it is not and issue of the system not being able to cool itself it's a matter of optimum running temp for the motor. Regarding pressure that is what the radiator cap is there for. because a good thermostat will actually have a bleed hole in it to help expedite the warm up period. And that is one of the other reasons that people end up going with thermostats rated at higher degree because some engines run better when hotter. The only reason to run a thermostat is that it will keep the motor within the optimum operating range where as without it the motor will essentially have a longer warm up cycle

jimdutro

iTrader: (1)

When I lived in Bullhead City, Az. in `75 I was driving a new `75 GMC shortbed 4x4, 350 4 speed and the radiator boiled over when the truck was parked all day! It ran so hot during the summer, I pulled the thermostat and it ran much hotter. Removed the inner workings of the thermostat, reinstalled it and the truck ran cooler. Never seen a car boil over parked since, good reason to have moved.

jccaclimber

If you put a torch by a pipe with flowing water you won't heat the water because there's a ton more water in total than if it was stationary. If you use a fast flowing pipe instead of a equivalent volume vat and the vat boils first its because the pipe is heating more evenly rather than heating a local section past the boiling point with the rest of the water slightly cooler. The pipe with the fast moving water actually picks up MORE energy in heat from the torch even if it boils slower. This is because the heat transfer is based on the temperature difference, larger difference (fresh supply of cool water in pipe), more energy absorption across the entire system (opposed to a local section). Also, convection is based on flow rate, higher flow rate, more heat transfer. This is why your radiator works better on the freeway than when standing still.

socal

if the air is to hot for the rad to lose the proper amont of heat then it will never cool down

if the rad loses to much heat it will never warm up

so how effecient is the rad (size, rows, brass/copper or aluminum) pump, air flow to engien bay/rad

how efficient is the motor 500hp vs 200hp the 500hp will put out more heat

it will differ per application so you just have to try for your self to find out. one thing i've seen is to drill 1/8" holes in the thermostat to let some water pass but still cycle with the stat and this can be seen with most aftermarket stats that have a small hole and a piece of brass or some thing to act a a check valve.

TeknoMaeg

OK... first off I am going to make a brief statement that I have read a bit of good information and a lot of misinformation. It's not so much that you are wrong... just misinformed or perhaps you made assumptions without proper knowledge.

You can run many cars without a thermostat... many people do it... but you have to keep in mind of a heating principle called Conduction and Convection.

Conduction is passed from solid to solid due to molecular vibration. It's the reason your aluminum heads will swell faster than your iron block. Same reason that ceramic spacers between your head and intake manifold allow for a more dense intake charge. The ceramic slows the vibration, hence slows the heat transfer.

Convection is the transfer of heat from a solid to liquid. It occurs on the thin layer of liquid between the solid and main body liquid. Same reason a bigger cooler works better. More are for the liquid to meet the solid.

Now both convection and conduction are based on the heating and cooling properties of the solids/liquids. Or rather the speed at which each can absorb and dissipate heat.

For example the thermal conductive of Water is 0.61... where as cast iron is numbered at an 80.

Then you have Aluminum at 240 and finally the best conductor, copper at 400. Keep in mind the conductivity of the molecule depends on the heat at which it currently sits.

Most of this is gibberish, I know... I don't follow myself some times.

Simply said... If you have an EXTREMELY efficient water pump but your block does not convect heat as efficiently then you will not cool as efficiently. Same goes for your radiator. If you have an inadequate cooling source, radiator, fluid or your engine simply generates too much heat... you will not get the full benefit of your cooling system if the flow is not slowed by a restrictor or thermostat.

It all depends on the engine and all the efficiencies of the parts.

You can have a top notch radiator but it the coolant is flowing too fast, it will not convect and conduct the heat away from your block fast enough. Same goes for if your radiator is weak or blocked in parts. it won't radiate heat away and out of the coolant.

Do you need a thermostat? No....

Would a small restrictor help you? I think in this case it would.

If it doesn't then you cooling system has bigger issues...

If you think I am wrong... please read this first.
http://www.engr.colostate.edu/~allan/heat_trans/page2/page2.html

socal

i agree just to lazy to explain it all out and look things up but thats the Jamie Hinamen sientific way of saying it

TeknoMaeg

GWW

Well, thanks everyone it sure seems as if under very special circumstances it could happen so it shouldn't be ignored-especially if your modified, hot weather, loss of air flow due to coolers or ram air ducting etc. I don't think it's happened to me, maybe my friend who says it has but then you've got to see his cars. They definetly fall under the not in prime condition category. Perhaps I will send this to the Myth Buster show.
GW

allencr

Yes, you're wrong. Do you have anything else that might offer the slightest bit of proof that a faster flow will pickup engine heat, which the radiator is unable to dissipate. I've looked at the site, and there is nothing in it even close to confirming your 'coolant too fast' Myth, except for a small section 'Nucleate Boiling of Coolant' on page http://www.engr.colostate.edu/%7Eall...ge8/page8.html
This is a real problem that a restriction can cure by upping pressure, but is commonly mistaken & continues the myth.

If you can find anything from any manufacturer or troubleshooting guide
about a missing thermostat being responsible for anything other then LOW temp problems, please let us know!


These might help.
http://yarchive.net/car/engine_water_restrict.html
http://www.stewartcomponents.com/tec...ech_Tips_3.htm
http://yarchive.net/car/radiator_diagnosis.html
http://www.grapeaperacing.com/GrapeA...ingsystems.pdf
http://www.radiatorinfo.com/radtip.html
l

allencr

Yes, you're wrong. Do you have anything else that might offer the slightest bit of proof that a faster flow will pickup engine heat which the radiator is unable to dissipate. I've looked at the site, and there is nothing in it even close to confirming your 'coolant too fast' Myth, except for a small section 'Nucleate Boiling of Coolant' on page http://www.engr.colostate.edu/%7Eall...ge8/page8.html
This is the real problem that a restriction can cure by upping pressure, but is commonly mistaken & continues the myth.

If you can find anything from any manufacturer or troubleshooting guide
about a missing thermostat being responsible for anything other then LOW temp problems, please let us know!


These might help.
http://yarchive.net/car/engine_water_restrict.html
http://www.stewartcomponents.com/tec...ech_Tips_3.htm
http://yarchive.net/car/radiator_diagnosis.html
http://www.grapeaperacing.com/GrapeA...ingsystems.pdf
http://www.radiatorinfo.com/radtip.html

And we should've read the
[ALSO, we should've read these Important/Useful : common cooling questions Sticky Thread on this before wallowing in this type BS.
https://www.thirdgen.org/forums/cool...ions-read.html
https://www.thirdgen.org/forums/cool...ns-read-2.html

jaredi

Nice smack down.

TeknoMaeg

Juvenile response at best...

Either way... I was a bit mistaken... the same principle I used to justify my theory was that one that destroyed it. My knowledge on thermodynamics is fair but that is it... fair...

So I was wrong... big deal... now I know more.

Also... registering a new name just to prove me wrong... come on now... I was just trying to help the guy...

jaredi

Am I juvenile that when I don't know for sure about something's accuracy that I either preface it with a disclaimer or keep my mouth shut?

You didn't know, but you spouted it off as truth anyway even after claiming to have known more than any of the rest of us having read all this information and sifted through it all to provide us with the shining beacon of a technical post that you made.

And it was wrong.

So who's making juvenile posts here?

And I'm not sure what you mean about registering a new username, if you're accusing me thats absurd, if I intend to debate someone on anything I'm going to use my own username so everyone will know it was me that brought the tech. This time I didn't have the time to fuss about and do the research.

And BTW, the nice smack down comment wasn't even aimed at you personally, it was directed to everyone I've ever heard spout this logic of "Well if it flows to fast then it won't have time to heat up in the block or cool down in the radiator" It just gets mind numbing. Every time this idea is debunked it pops right back up again with someone else defending it.

GWW

Fellow Third Geners.
I honestly have to say I did not read that sticky before posting and for that I'm sorry. However even after reading it I still found some of the information here new, interesting and fun to think about, downflow radiators, steam pockets...
That's my purpose to come to this site, I enjoy it, cars are my hobby. Too old too fat, and too mean to do much else . I'm sorry I caused a fuss I will be more carefull next time.
If you see it on Myth Busters you'll no where it came from.
Again sorry for the trouble this may have caused, certaintly wasn't my intention. Moderator can lock or delete this post if you feel it's necessary.

jaredi

I thought it was pretty mild. LOL. I guess I'm just used to the corner carvers forums... Its all in the name of good tech.

Apologies if I ruffled some feathers, and props to allencr for bringin the tech and props to TeknoMaeg for at least taking to time to research it and try to help.

Ford2transam

I ask a few question before answering:
Built or any aftermarket motor parts? (I guess yes)
the rad is it stock? did the rad shop test it and it and say okie dokie?
But point blank you need to cool it so if their is not a vapor lock in the system i'd say you'd need a larger rad. At the least if your have a 2 core rad get a 3 or 4 core or some nifty after market antifreeze you can find at most auto stores. Without more info this is just a guess, respond with answers i'll give another suggestion