Thermostat - Does opening temperature matter? Options

[woodst]

Hello!
I am rebuilding a frozen 1.8 engine and found a thermostat with an opening temperature of 90°C in it. It works fine - but for the stock engine an opening temperature of 65-70°C is recommended

Does it matter? New ones are hard to find or quite expensive.

I won't drive the car in winter but we have mostly intermediate temperatures at about 20°C. In summer it's actually pretty hot >30°C. Thanks to global warming...

BTW: I want to keep my flaps. There are lots of discussions whether they are useful or not. Please do not go into this again. I want them installed.

Cheers!
Malte

[Bartlett 914]

Hello!
I am rebuilding a frozen 1.8 engine and found a thermostat with an opening temperature of 90°C in it. It works fine - but for the stock engine an opening temperature of 65-70°C is recommended

Does it matter? New ones are hard to find or quite expensive.

I won't drive the car in winter but we have mostly intermediate temperatures at about 20°C. In summer it's actually pretty hot >30°C. Thanks to global warming...

BTW: I want to keep my flaps. There are lots of discussions whether they are useful or not. Please do not go into this again. I want them installed.

Cheers!
Malte

You are correct about the flaps. They are important and the motor will cool better with them in place. The thermostat only helps when the motor is cold and allows the motor to warm up a little faster. I suppose you could install the thermostat with the cable a little loose. You just want to make sure that the thermostat expands enough that the flaps are fully in the relaxed state (as if the cable was disconnected) when warm. Here is an informative link

Thermostats explained

[woodst]

Thanks, Mark for your help!
I know the mentioned article and that's why I ask for the different opening temperatures. I would never had noticed there are different types around....

If I understand you right, I can go with the 90° thermostat and the engine will warm up more quickly. That's it?
Or does it mean my engine will run on a higher temperature level, because the flaps will start to open approx. 20°C later? I don't know anything about the normal air flow temperature.
Maybe, it's far beyond 90° and there will be no restriction using another thermostat with higher opening value.

Should I convert a Type 1 thermostat? These are still available and pretty cheap. But they look completely different.... They actually use a coil to actuate the flaps instead of the "discs" of the original one.

I just want to get right....

Cheers!
Malte

[Cupomeat]

Hello!
I am rebuilding a frozen 1.8 engine and found a thermostat with an opening temperature of 90°C in it. It works fine - but for the stock engine an opening temperature of 65-70°C is recommended

Does it matter? New ones are hard to find or quite expensive.

I won't drive the car in winter but we have mostly intermediate temperatures at about 20°C. In summer it's actually pretty hot >30°C. Thanks to global warming...

BTW: I want to keep my flaps. There are lots of discussions whether they are useful or not. Please do not go into this again. I want them installed.

Cheers!
Malte

You are correct about the flaps. They are important and the motor will cool better with them in place. The thermostat only helps when the motor is cold and allows the motor to warm up a little faster. I suppose you could install the thermostat with the cable a little loose. You just want to make sure that the thermostat expands enough that the flaps are fully in the relaxed state (as if the cable was disconnected) when warm. Here is an informative link

Thermostats explained

That is a great link to a great article.

Thanks!

[Bartlett 914]

If I understand you right, I can go with the 90° thermostat and the engine will warm up more quickly. That's it?
Or does it mean my engine will run on a higher temperature level, because the flaps will start to open approx. 20°C later? I don't know anything about the normal air flow temperature.
Maybe, it's far beyond 90° and there will be no restriction using another thermostat with higher opening value.

Should I convert a Type 1 thermostat? These are still available and pretty cheap. But they look completely different.... They actually use a coil to actuate the flaps instead of the "discs" of the original one.

I just want to get right....

Cheers!
Malte

If you want to get it "right", get the proper thermostat! 90C is pretty hot. It may be safer to not use a thermostat (leaving the flaps in place) than having too hot a thermostat. This is only used in warm up. Warm up will only be a little slower without the thermostat.

I know nothing about the type 1 thermostats.

If you place a WTB in the parts section, I think you may find a proper one at a reasonable price. Shipping may be a cost problem. It wouldn't hurt to try.

[Archie]

Thanks for the great link to the thermostat diagnostic/repair article. So much still to learn about these cars!

[realred914]

My understanding of the system is the thermostat is not only used for warm up, it also controls the temp as the engine temp varies, high load on the freeway going up a steep grade may require it be full open, low load down hill, (fan at high rpm) and the flaps may start to close some.


get it out of your head that this is only for warm up or such.

get the right part, they can be found, ebay, here , craigs list the samba,ever just get the right part and do it smart, not cheapo (if you do, you'll pay and pay later).

would you run your Ford, Toyota, GM, or Honda with the WRONG thermostat? would you remove the thermostat? I would think not (no sane mechanic would) why put a hotter running thermostat that you found in you car? why would you want to risk runing too hot to save $50-$100????

get the right part, and remember the thermostat is NOT ONLY FOR WARM UP