Thread: 180 T-Stat

Originally Posted by TDCRacing

Thanks for explaining you're self. And again the only reason i have a thermostat is to keep the engine as cool as possible. Not for performance.Not for any gains in mpg or horsepower but to simply not let the engine heat up as much to try to preserve it as long as i can lol.Is it really helping in doing that? ehh...probably not... but sometimes as you said it's the little things that count.

Take it easy man.

I don't understand this? I don't see any gains in keeping your engine cool. No performance. No economy. I just don't see the point in keeping the engine cool. You need a hot engine to make more power and better economy. Just take a look at Nascar engines. They typically run 230°-250°F. They don't try to keep their engine down to 160°F because they know there is no point in it.

My main complaint with the stock tstat setup is this. It heat soaks and absolutely saturates the heads until it opens up. With the tstat closed, there is precious little coolant flow through the block and heads (only the heater core is getting flow, really). Your coolant sensor is right beside the tstat on the LIM.

While the tstat and ECT sensor are seeing about 190* (just before opening of the stock tstat), the coolant that is just sitting still in the heads and block around the cylinders could be reaching 250+. It's just stopped soaking up heat and letting the heads get super hot. If you're viewing the temp on a digital gauge (since the dash gauge is sluggish to react), you can see at the point of the tstat opening the coolant temp spikes as all this super hot coolant comes out towards the radiator. Now, what's worse is in winter after all that super hot coolant is gone it's replaced with super cold coolant from the radiator. This alone can crack parts.

The bottom line of all this... get a drilled tstat, even if it is only stock temp. This will keep coolant from just sitting still. Yes, the car will take longer to heat up (about 50% longer, as I am realizing after installing a drilled Saturday) to full temp. But, to me it's worth it to keep sudden shocks to the system minimal. Can you imagine what it must be like for your engine to have some parts with coolant sitting at over 250*F then suddenly get jammed with -15*F coolant?

I agree that heat soak can be an issue when drag racing. For that reason, I run a cooler t-stat when racing. But not any other time because heat soak isn't really an issue. What do I care if my incoming air is a little hotter while sitting in bumper to bumper traffic. I don't WOT immediately afterwards. So performance isn't really an issue in that case.

As for the coolant just sitting in the heads, sorry, but it doesn't. Typically the open and close of the t-stat during normal operation is a constant in and out. Usually soon after it closes, it will open right back up. It doesn't stay closed for long. And the water pump is a constant moving part that is pushing the coolant all the time. So it has that pushing the coolant around as well. And not to mention that warm water will rise, and cold will fall, so as the coolant is heated, it will immediately rise to the top of the coolant system, which is where the t-stat and temp sensor is.

Also, you mention the -15°F coolant hitting 250° coolant. Again, this simply does not happen. As mentioned, the water pump is churning all the time. While it is taking in cooler coolant, it is constantly mixing that with the hot. So by no means will -15°F coolant ever meet 250°F metal. Unless of course you are silly and run without a t-stat or something like that. But even on the coolest of days, down below 0°F, after my drive to work, my radiator is warm, almost hot to the touch. So I would imagine that on the coldest of days, the coolant in the radiator still gets to a warm 140°F.

And I think you are thinking that the t-stat opening will let in this rush of freezing cold coolant. It just doesn't happen that way. Your t-stat functions very quick at the operating temp. Put it in a pot of boiling water and watch it move. Then drop it in a pot of cold water. It closes immediately. So as soon as the coolant temp hits 195°F, the t-stat will start to open, and as soon as it drops to around 190°F, which doesn't take too long, it will close shut.

So in no way does the coolant ever, ever sit still. Simply not an issue because it never does this. It has the water pump pushing all the time, the t-stat constantly opening and closing, and the fact that as the coolant gets warm, it rises automatically to the top, where it will contact the t-stat and make it open. It never sits still.