thermostat..to use or not?

[mugen9]

hi guys..

I know this a repeated thread and just to repost again so that we can discuss again to share our experient with or without it...

Lots of discussion in the Net about this thermostat..small THING but da*n headache if poblem..I can't take 100% in the Net coz their weather is not as HOT
and unpredictable as Malaysia...and especially for our beloved & high revvin'
Great VTEC engine...not to forget that the design of radiator ( especially EG came with small radiator and not aluminium ) ;) Definitely Honda Engineers have a good reason why they design this small radiator isn't it?

Many Brand & type of thermostat..Mugen,Sard,Honda OEM,etc..different operating temperature...68 Deg,78 Deg,81 Deg C...

So, my car been running WITHOUT thermostat for nearly 3 4 years & NO overheating problem..;) I change the water pump together with timing belt ( 70k km & using dual core aluminium radiator..the problem are :-

1) morning engine warm-up = > than 10 minutes
2) after 10 minutes, feel a bit 'sluggish' coz I think the engine still didn't reach
it's operating temperature...
3) night driving ( > 12 am ) & during raining temperature drop nearly Cold


after about 1 hour constant driving, then I can 'feel' the engine a bit 'ringan'..
after that baru best...hahah

So, base on your experient :-

1) do I need to to install back the OEM thermostat ( opens at 81 Deg C )?
2) I think we better change to new thermostat when times come ( about every
30k km )
3) or buy Sports thermostat ( open < than 81 Deg C ) price ? where ? brand
suggestion?

definitely I'll feel uncomfortable after re-install it ...:) coz we stay in Klang Valley
area which we can't avoid traffic jammed & stuck with your girlfriend / wife & kids...your eyes keep staring at the temperature gauge more than front car..haha

what do u think all VTEC kakis...share your opinion / experient ...we discuss together...

Hattech-v..u always high revvin your car, u use thermostat or not?

 

[mrbear]

ok basically what from my experience with DOHC VTEC engines (that im having rite now)..

i bought my car for about 1yr ++ ago. its been ok for a while,until about 7-8months having it.. one day my temp suddenly raise too high when idle. but when its moving,the temp idle would drop.. or else the other way around.

(my temp gauge is fully digital,so no 'needle' just bars till the end.)

the story is that when i send the car for the 1st time.. my mechanic detects that when turning on the ignition keys,my radiator fan would spins out 1st. they said that the fans have been bypass (they told might be because overheat thing?). but they manage to uncut the bypass. 7-8 months later my car having a really bad overheated engine.

so send my car to the garage,change the sensors,ovehauled the radiator back,do some testing this n that. it was OK! .. but the prob is that when the car idle,the temp would shoot high!.. but when its moving,the temp is normal.. it was going for about 2-3 weeks (i had no time to send the car,but im really damn afraid of traffic jams!) scared out of me..

then going back to the mech garage again.. check check check all things.. this n that. but then they didnt find any fault on it ... suddenly one of the mech,ask to check the thermostat! .. (why do i dont think about this?) hahaha.. then they open the water pump,there's is no thermostat inside? .. weird.. then the story flashes back .. (no wonder last time,my car had a radiator fan bypass)..

then,since im going to have a new thermostat.. ive manage to get SPOON Thermostat and also SPOON thermoswitch for my H22A. fix it all well. then bring my car home,then do some monitoring,then the problem solved. until today i didnt had any problems of overheating again.

* my mech told that,if there's a thermostat inside but the car still overheating,you might be need to change a new thermostat or else REMOVE the thermostat at all and dont use. but later if the engine still generates overheating again,do fix back the thermostat. and the problem solved! ..

(its vice-versa.if overheat,fix thermostat or the other way round,if got thermostat,remove it)

Difference with / without thermostat: (for my car/engine)

With:
1) easy start
2) no need to wait for a long warming up (its fast,few minutes!)
3) engine feels smooth n lighter

Without:
1) easy to start
2) takes about 10-15 minutes to warming up
3) engine slightly feels a bit sluggish (can feel the different with n without)

i did some research also regarding having a thermostat inside the water pump!
but what i understand is that:

If having thermostat:

* when the water temp rise/heat/boiling inside the engine block,the thermostat will open/release the pressure so that the hot water inside the engine block goes back to the radiator and the fan will spins to cool of the water,when thermostat opens,it allows the cold water flowinng from radiator to the water pump/engine block. and the process continues. when its hot,it opens,flowing hot water from engine block to the radiator and also pumping in cold water from radiator to the engine block again. (the process repeats again and again n again)

but can u imagine ur water pump without thermostat? it will flows hot water to the engine blocks at all time without having it been cooled down.

im not sure if this is a correct explaination. but this is thru my experience n research.. hehehahah..

maybe other VTEC cfoo can explain more?



A thermostat is a device for regulating the temperature of a system so that the system's temperature is maintained near a desired setpoint temperature. The thermostat does this by controlling the flow of heat energy into or out of the system. That is, the thermostat switches heating or cooling devices on or off as needed to maintain the correct temperature.

Thermostats can be constructed in many ways and may use a variety of sensors to measure the temperature. The output of the sensor then controls the heating or cooling apparatus.

The primary function of the thermostat is to allow the engine to warm up quickly by controlling coolant flow to the radiator. When you start your engine the controlled explosion known as internal combustion begins. As heat builds inside the cylinders, the coolant in the passages around them begin to absorb that heat. The thermostat opens to allow coolant flow only after the engine reaches proper operating temperature. Hot coolant flows away from the engine and into the radiator to cool off. Seconds later it returns to the engine to absorb more heat. So goes the operation of your vehicle cooling system.

 

[shiroitenshi]

like bear said.. it's just something to regulate the coolant flow.. something like a check valve controlled by temperature. I don't know more than that.. which is why I'm still using the stock one.. :P

 

[hattech-v]

use it laa... if not honda engineer will not put it when they design the engine... haha

 

[crower75]

use it..
very useful if u always wake up late for office...will save u a lot of time for warming up the car. w/out thermostat, it'll take u more than a ciggie to fully warm up your car.

 

[mugen9]

tq guys for your reply...

Mr. bear, good explanation...the different is you have a big & wide radiator..not as mine (EG) small only..some more engine bay is cramped...not much space for air to
flow all around ...how much u got for the spoon thermostat & thermoswitch ? what's the opening valve Deg? where to buy & price ?

the thermoswitch is it the same as Auto Fan switch ?

before adding again the thermostat, I just want to find which one os more RELIABLE & lower opening valve compared to the OEM Honda...most of the cases
the thermostat, inside spring got stuck & won't open...

what I learn is that , we need to use radiator coolant to slow down the boiling process ....

where can I buy aftermarket thermostat ( lower Deg opening valve ) other than Sunway ?

TQVM

 

[IVAN TAN]

i used arc thermostart 68 deg,wif motul coolant........ double layer radiator
not kena heat 3 yrs.
mr expricezzz.. chnging thermostart jus slow down the boiling point , but it not help u to bring down some heat for the engin, my temp still 93 deg sometime 95 deg while the weather is ver hot and worse traffic.........if over 95 deg....... problem coming .... overheat soon...........
i prefer change fan swith ( ori 93 deg) try to get some low temp fan switch, bcos i found only fan move early only can give us a better engin cooling,mjus some opinion..... thankz

 

[shiroitenshi]

what I learn is that , we need to use radiator coolant to slow down the boiling process ....
TQVM

Hmm.. from what I know, the radiator coolant is a mixture of antifreeze and some other chemicals to provide better heat transfer (the heat transfer thing only available on some coolants.. I think they call it water-wetter or something)

The radiator cap is the one that slows down the boiling process.. actually not directly.. what it does is increase the pressure inside the radiator, hence increase the boiling point of the coolant.

That's why the radiator cap is measured in bars.. 1.1 for stock, 1.3 for mugen/spoon units.

 

[evoX2]

is it ok to change to 1.3 on stock radiotor?

 

[b-eater]

what are the different using oem thermostat btween aftermarket thermostat??
and what are those degree for?

 

[shiroitenshi]

Like Ivan says.. get a fan switch to help cooling.. I'm using spoon's one.. but for those in the know.. there's no difference in the brands.. just the numbers on the unit matter...

I'm using 80.. which means it opens at when engine heats up to 80 degrees.. stock B16A is 90, I think.

Of course, I never had a over heating problem to begin with, but I think it's soon, since my radiator plates have been bent by driving too much on the road and getting hit by small pebbles and the like.

 

[mrbear]

tq guys for your reply...
how much u got for the spoon thermostat & thermoswitch ? what's the opening valve Deg? where to buy & price ?

H22A Spoon Thermostat: RM2xx
H22A Spoon Thermo Switch: RM2xx
H22A Spoon Radiator Cap: RM10.00 (from h/cut) hahah :mouth_closed:

* my cousin is studying in japan. last year before he came back,i ask him to find for me,he manage to get it. but i remember it was about around RM2xx pr pc? if im not mistaken. (long time d,dun care.. its SPOON!) hahah..



http://www.aj-racing.com/catalog/files/products/images/spoon/engine/Thermostat.jpg
Spoon Thermostat
The stock Honda thermostat opens when the water temperature reaches 88C. The Spoon thermostat improves cooling performance by lowering the opening temperature to 65C and is fully open at 70C.

http://www.aj-racing.com/catalog/files/products/images/spoon/engine/Thermo-Switch.jpg
Spoon Thermoswitch
The stock Honda thermoswitch turns on the radiator fan when the water temperature reaches 98oC. The Spoon thermoswitch improves the radiator's cooling efficiency by turning on the fan at 80oC.

http://www.aj-racing.com/catalog/files/products/images/spoon/engine/Rad-Cap.jpg
Spoon Radiator Cap
A radiator cap functions to increase the pressure inside the radiator so that even if the water temperature exceeds 100C, boiling will be avoided. Stock Honda radiator caps are rated at 1.1BAR.

* i strongly suggest to use Radiator Coolant.. its perfect!..
* about the radiator cap.. i dont know whats the different between 1.1bar with 1.35bar .. (tried both on dyno,looks the same doh?) nuthing n does not feel any difference at all.. (dont know for short term or long term)

* MUGEN also produce the same as Spoon products on Thermostat n Thermo Switch.

 

[shiroitenshi]

Spoon Thermoswitch
The stock Honda thermoswitch turns on the radiator fan when the water temperature reaches 98oC. The Spoon thermoswitch improves the radiator's cooling efficiency by turning on the fan at 80oC.

* about the radiator cap.. i dont know whats the different between 1.1bar with 1.35bar .. (tried both on dyno,looks the same doh?) nuthing n does not feel any difference at all.. (dont know for short term or long term)

Stock one at 98? Hmm.. I don't remember very well, but I remember pulling the stock one out of my B16A and it reads 90. Not debating your info.. rather maybe there's a possibility that there's a few that has different ratings according to model/year.

The radiator cap helps increase the boiling temp.. not boiling = no air bubbles.. air bubbles = bad.. Air transfers heat WORSE than water, so you can see why that boiling point need to be avoided.

Unfortunately, I don't think the dyno will show any results for better cooling performance.. the engine works best at it's proper operating temperature (whatever that may be) since at that temperature, the block is heated up to a point where the clearance of the pistons, the seal of the rings, etc. is just right.. It's a balance between too cold and too hot. I don't think supercooling your engine with liquid nitrogen will result in extra hp.

(unless you're spraying it on an intercooler, but that's not cooling your engine, that's cooling the intake charge, which is another story)

That why if your engine too cold oso not good, e.g. in the mornings, where the engine after started up feels different than when you've warmed it up properly.

That's also why forged pistons have very different clearances when reboring, and why it's more important to keep the engine from overheating on 'built' engines, where it might cause the clearances inside the bore to change, causing seizure and damage/premature wear.

In my opinion,
Using all those parts help DELAY that point where the engine heats up to a critical point. Engines heats up with use.. more power extracted from engine, more heat will result.. that's why drag cars cannot use on track.. they will overheat easily, and that's also why track cars are built generate less hp compared to drag monsters.

Malaysia has hot weather.. so we need radiators and stuff.. anyone seen a foreign car in a foreign country without a radiator unit? (O_o) (apart from air cooled VW engines lah)

 

[hattech-v]

stock thermostat open at 78C.

 

[evoX2]

for swap to 1.3 bar cap is ok for stock radiotor?

 

[IVAN TAN]

my stock thermostart = 78 c
arc = 68c, for me no really .... help for cooling..........
my feeling still think that thermostrat jus slow down the boilling point. but it not help to bring down a boiling poit. ...... i prefer low temp switch........ it help more for colling........ thanz

 

[hattech-v]

for swap to 1.3 bar cap is ok for stock radiotor?

i'm using it with stock radiator for almost a year+. no problem.

 

[xxxx]

1.3 bar is ok as long as all ur rubber hoses can withstand the pressure....n parts tat' s involved in the cooling system too.....haha

 

[IVAN TAN]

my think std enuff lo.....for cap....... ha ha .... all the best,,,,,,,

 

[nan83]

The thermostat is a device to control the temperature only AND NOT A COOLING DEVICE.
Cooling element is radiator, cap & coolent. If your cooling system only can cool the engine to 80'C, so the 68'C thermostat cannot function, it will open all the time just like not using thermostat. So you must upgrade radiator, cap & coolent to transfer more heat, then the thermostart start funtioning to control the temp. at 68'C. Get what i mean?? You also need to set back your FAN control to on the fan at around 68'C.

IF YOU USING STOCK ECU, NO NEED TO COOL DOWN YOUR ENGINE!!!!! COZ THE ECU IS TUNE FOR THAT TEMPERATURE OF ENGINE!!!! JUST MAINTAIN THE COOLING SYSTEM AT OPTIMUM PERFORMANCE.

SO WHAT PURPOSE OF LOW TEMP. THERMOSTAT????
It use for racing engine to produce more power. Most important must have progammable ECU to tune back yor engine to get the power of cool engine. While the eng temp drop, air entering the engine less creating a denser fuel/air charge thereby developing more power. Cooler induction air is less prone to induce spark knock so the ECU can run more aggressive ignition timing resulting in greater power.


Coolent information.

-cheap coolent are not cooling yr engine. the chemical inside the coolent(glycol base) just for anti-rust & anti-freez. So just pour a bit to your radiator for anti-rust & lubricate water pump. Pure water have batter cooling than water mix with coolent, but pure water will corrode the system faster.

- hi performance coolent like redline water wetter, lubeguard Cool-It & other hi performance coolent is good for cooling. But it will cost u $$$$.. hehe.. wanna know how it cool the engine, use google.com to find yourself.. :p