Running without Thermostat - Cools better?

[tricky]

For anyone who thinks a thermostat isn't important, I dare you to build up an engine, then leave the thermostat out for laughs. Try bedding in the rings without the thermostat, and the engine constantly running cold... I do beleive that will change your opinion of the importance of a thermostat.

[beatle]

the bad thing IMHO about not running a thermostat, is the water doesnt get a chance to sit in the radiator and cool down, so it wont take such a sustained flogging before getting too hot

[Kyosho]

the bad thing IMHO about not running a thermostat, is the water doesnt get a chance to sit in the radiator and cool down, so it wont take such a sustained flogging before getting too hot

The actual issue is the water doesn't sit in the ENGINE long enough to remove hte heat from the engine.
The coolant stays cool, but the metal gets hotter.

[allencr]

Quote:
Originally Posted by beatle
the bad thing IMHO about not running a thermostat, is the water doesnt
get a chance to sit in the radiator and cool down, so it wont take such a
sustained flogging before getting too hot


The actual issue is the water doesn't sit in the ENGINE long enough to remove hte heat from the engine.
The coolant stays cool, but the metal gets hotter.

WTF! I give up.

[roadsailing]

short answer: run a thermostat

it is a control device designed to keep the water at a specific temperature, not jus ta "tap" that opens when the engine has reached operating temp.

i drove my car for ages with a stuck open thermostat, when i replaced it with a working one everything got better.

just run one, there is no reason not to on a street car.

[Grega]

heres a practical application of no thermostat
i changed my waterpump on my ae92 4AFC today
the old pump was fuxoid and now the car runs COLD as - there is no thermostat in it (or its jammed open)
as a result - when cruising on the freeway, my car runs on C - i don't get 4th gear in my auto as the temp is too low for it to engage. so at 100kmh i'm doing 3500rpm instead of the usual 2200rpm.

one thing worth noting, i run a VN V6 which is supercharged (173rwkw) and i run a colder thermostat and 1 heat range lower plugs. car runs at normal temp though. this is a buick POS motor though remember and has been tuned to run with the cooler thermostat ect.

my 2c.

[wa5]

That is just an old wives tale/myth that refuses to die, only because there is a rare bit of truth to it, unknown by those passing it along, that it's a false assumption, and even then, it sounds so ridiculous to begin with, I don't know why it ever had a life at all. The faster flow would pickup less heat, thus there's less to dissipate - Done. The exception I've heard about where it actually is true & convinced those that it was the speed, would be tough to figure out, so I can't really blame those few about real cause.................... It is a pressure decrease causing the overheating, not system from hot air & water, but head/water pressure in the head An open thermo. will restrict flow, increasing pressure enough to stop those nasty but normal hot spots from bubbling & getting cooled even less during a hard run................... You must run some serious water pumps in the US cause the ones we run Downunder cater for Volume NOT Pressure. seriously how would the pressure change by any measureable amount between the back of the head and the bottom radiator hose?

You've already proved by yourself that it'll run cooler and if you've got a thermo on the inlet side of the system, then even the exception will never happen with the restriction at that location.
Some of these Toyota's have huge bypass systems, so you wouldn't get the usual problems with running way too cool.

................................

[kylestyleup]

Hello guys...

This is very interesting...
Still I can't buy a correct thermostat. I'm still running without it.

I have read from one of you that the water will not cool-down through the radiator.
I noticed that the radiator is hot on top and cold at the bottom (as in metal cold).

While reading all your discussions, a questions just hit me in the head...
If engine must ( I say a must ) run in a certain temperature,
why do people buy or install a performance radiator and a really nasty water pump
if we don't want coolant to flow freely and cool-down better?

[jimmmayyy]

The idea is to maintain the coolant at the correct operating temperature of the engine, usually around 86-88 degrees. A hipo engine creates more heat so therefore needs a better radiator. about the pump, well i guess sometimes people just wanna stinge.

btw your from QC?? or are you in Australia? Like i was saying in my previous posts, I don't have any thermostats in my cars in PH (Lived in Manila for a few years, and missus' olds live in LC, Quezon), it just never gets cold enough over there for it to ever be a problem.

[kylestyleup]

The idea is to maintain the coolant at the correct operating temperature of the engine, usually around 86-88 degrees. A hipo engine creates more heat so therefore needs a better radiator. about the pump, well i guess sometimes people just wanna stinge.

btw your from QC?? or are you in Australia? Like i was saying in my previous posts, I don't have any thermostats in my cars in PH (Lived in Manila for a few years, and missus' olds live in LC, Quezon), it just never gets cold enough over there for it to ever be a problem.

Yes from QC. I'm not in Aus... plan to look for a job over there in the future though.
Might come across with someone looking for a Graphic Designer for Web and Prints
for even just an $800 AUD a month as a starting pay.

OK, I'll just keep on observing my cooling system.

[jimmmayyy]

phew you'd have a hard time living on $800 a month here. PM me if you want any info.

Anyway yeah, your car should be fine without, especially in Manila. It's fucking HOT all the time as you'd know, lol.

[kylestyleup]

phew you'd have a hard time living on $800 a month here. PM me if you want any info.

Anyway yeah, your car should be fine without, especially in Manila. It's fucking HOT all the time as you'd know, lol.

You got PM...

[The Real Roadrunner]

The actual issue is the water doesn't sit in the ENGINE long enough to remove hte heat from the engine.
The coolant stays cool, but the metal gets hotter.

this is INCORRECT, the only reason they over heat is due to the water not being forced hard against the cylinder/chamber walls.
ive run cars with no thermostat b4 but i ALWAYS cut the guts out of orig thermostat then fit the outer section back into the housing , thus causing a restriction therefore more pressure on the cyl walls which increases cooling,
most of our track cars run like this as they produce bulk HP and need more cooling but they still need some sort restrictor otherwise they just overheat.

[wa5]

if a normal water pump had to double as a preasure pump rather than just circulate the coolant it would stall / cavitate. the preasure inside a cooling system is due to it being sealed and the fact that water / coolant expands when heated.

could anyone who subscribes to this thermostat/ preasure theory please explain and demonstrate exactly how the preasure would differ by any appreciable amount between any two points in the sealed cooling system that they care to nominate.?

if you can show any mass produced car with a preasure type water pump (that is multi gear like an oil pump) as opposed to a simgle impeller (single fan blade), that may go some way towards convinceing me (but probably wont )

[The Real Roadrunner]

opposed to a simgle impeller (single fan blade), that may go some way towards convinceing me

so i suppose a turbo wont produce pressure because its an impeller? well i suppose i should get a supercharger.