Are there racing thermostats?

[tbro]

Magna-blue,
when you tested your thermostat did you test it with the thermostat suspended, ie: the unit hanging off some wire supported by a piece of dowel?
If so then I would agree with others comments that you have problems somewhere else.
If you test with the thermostat contacting the pot of boiling water you will get an incorrect reading etc.
Pretty well most thermostats manufactured these days usually fail in the open position, still causing overheating problems but not as quickly as a fully closed one. In your initial post you said that the guage went from cool to toast several times in a lap, pointing to the fact the thermostat was working, maybe check the temp cooling fan sensors ??

Just something to confuse the living cr#p out of you

Terry

[adamjp]

http://mx5cartalk.com/forum/viewtopic.php?f=29&t=34597

[manga_blue]

The only time I had cooling issues was after I had the core cleaned out. Replacing the radiator fixed it. So even if you think it's OK, and people have tested it, doesn't guarantee it's perfect.

try this for thoughts:
http://www.google.com.au/search?q=therm ... cmiata.com

Aaaarrggghhh! So many discussions about thermostats there! No one there seems to have a good answer yet for one set-up for driving both to and on the track.

Results 1 - 10 of about 420 from forum.specmiata.com for thermostat

when you tested your thermostat did you test it with the thermostat suspended, ie: the unit hanging off some wire supported by a piece of dowel?

maybe check the temp cooling fan sensors ??

Just something to confuse the living cr#p out of you

a) Nope, they were all sitting on a saucer in a steamer basket suspended in the water while it was being stirred. Like your idea better.
b) I don't think cooling fans play any part once you're on the track. There's already a 140kmh wind blowing through the radiator and it's probably spinning the fans faster than they could go under their own power anyway. Fans are for traffic jams.
c) Makes no difference. I'm confused about nearly everything all the time anyway.

[Okibi]

... No one there seems to have a good answer yet for one set-up for driving both to and on the track....

... They also have a nice 78" thermostat with a bigger/longer opening.

http://www.maruhamotors.co.jp/miata/parts/watertempsensor.html

If you want a quote email Saiji via info@maruhamotors.co.jp.

[Fatty]

but his car is an na8, the maruha jobby is for na6 only i think?

[mx52nv]

From Maruha's website -> clicky

Maruha 78 (Seven Eight) Thermostat with Long Stroker for Best Radiator Performance
Support MIATA models: NA8 models, NB models (except for NA6CE)

Les @ MX5 Shop

[Okibi]

My bad
78Thermostat & WaterTemp Sensor Adapter Kit for NA6CE
http://www.maruhamotors.co.jp/miata/parts/watertempsensor.html

Maruha 78 (Seven Eight) Thermostat with Long Stroker for Best Radiator Performance
Support MIATA models: NA8 models, NB models (except for NA6CE)
http://www.maruhamotors.co.jp/miata/parts/78thermostat.html

[de Bounce]

Just leave the whole thermostat out? Be careful with the thread as it is easy to cross (grumble...)

No you can't do that, The water will flow too fast through the radiator not giving it enough time to cool.

X3
The flow needs to be controlled (slowed) allowing it to absorb the heat from the internals and then dissipated through the radiator.

Another thought is the type of coolant used!
Have a read of this article from the MX5 Club in WA
http://www.mx5club.com.au/technical.php

Another area is the oil system which does a fair bit of cooling in an engine.

[orx626]

The flow needs to be controlled (slowed) allowing it to absorb the heat from the internals and then dissipated through the radiator.

Sorry mate, but this is not true. People think that heat and temperature are the same thing. Heat is energy, of which temperature is a variable that determines how much heat something has. Slowing the water flow actually reduces the ability of the water to remove heat from the engine because the temperature difference between the water and the engine being cooled (delta T) decreases as the water temperature increases. As the temperature differential gets closer (smaller) the efficiency of the heat transfer reduces considerably. So the faster the water flow, the smaller the temperature increase in the water, thus the delta T doesn't reduce as much, therefore the higher the heat transfer. The next trick is to get the heat out of the water into the ambient air efficiently.

Cheers,
Danny

[Okibi]

Thats good to know Danny, i've been told that it needs to be slowed down too.

[GP]

Sorry mate, but this is not true.

You may have misunderstood. The thermostat has a restrictive hole in it, If you take the thermostat out the water flow increases. The flow needs to stay the same as when the thermostat is in.

[orx626]

Sorry mate, but this is not true.

You may have misunderstood. The thermostat has a restrictive hole in it, If you take the thermostat out the water flow increases. The flow needs to stay the same as when the thermostat is in.

No misunderstanding here. My response was with regards to de Bounce's statement. What you may be referring to is the job that the thermostat can play in ensuring that the water flow from the pump does get to all the areas of the engine that is required for proper engine cooling. In some engine designs the thermostat is absolutely critical for this to happen, and if it is removed, flow from the water pump pretty much bypasses the engine resulting in overheating.

Regards,
Danny

[manga_blue]

You're making sense, Danny. That's a rare thing here.

[GP]

No misunderstanding here. My response was with regards to de Bounce's statement. What you may be referring to is the job that the thermostat can play in ensuring that the water flow from the pump does get to all the areas of the engine that is required for proper engine cooling. In some engine designs the thermostat is absolutely critical for this to happen, and if it is removed, flow from the water pump pretty much bypasses the engine resulting in overheating.

Sounds like your in agreement then, Speeding up the water flow will cause overheating.

[orx626]

Sounds like your in agreement then, Speeding up the water flow will cause overheating.

I'm not in agreement Graham. I'm talking about the function of the thermostat directing the water flow, not the speed at which the water flows. Besides controlling the cooling system operating temperature, the thermostat manages the cooling water distribution between the radiator and the engine. Changing the speed of the water pump or changing the resistance to flow (ie. removing the thermostat) affects the performance of the water pump and this can lead to overheating. The performance characteristics of water pump are matched to the engine cooling system (flow and pressure). Changing the resisitance to flow can cause unwanted side-effects (ie. over-heating).

Regards,
Danny