squealingtires

iTrader: (14)

I think an adjustable thermostat would be a worthwhile modification. I'm not sure how it would be designed but that would be fairly simple (DC stepper motor, adjustable valve, electronic controller for motor control based upon preset and coolant temperature)



Advantages:

• run hotter to extent oil life by driving off the water in the crankcase
• run cooler for better performace and reduced detonation
• Open the valve completly and switch on your electric fans for maximum cooling

ArcticZ28

iTrader: (14)

I would think it would take too much money to manufacture when it is simple enough to just buy whatever temp thermostat you need for your app. Granted you don't get all of the benefits of above, but you get one for sure and most of another (take your pick). Not to mention, I'm not sure how long an electric motor would last being exposed to such hot temps for so long.

gametech

iTrader: (1)

Sounds like Rube Goldberg in the house! Seriously, though, no real benefit to the idea.

toprintonbothsides

Why build and fly a plane a mile when you can walk there now? It would be overcomplicated, cost too much, and break down to much. Thermostats now cost what three dollars? They work just fine. My car stayed cool in 90 degree rushour traffice with a waterpump with no bearings. Ideas like that are why we end up paying two hundred dollars to replace tail light assemblies rather than a twenty cent bulb.

Keith

Unlike these other people, I think you have a good idea there. You could control the flow rate via a simple stepper motor. And you would vary the amount of time that the coolant stays in the engine and the amount of heat that it will absorb.

Voila - your adjustable thermostat.

TryingT/A

iTrader: (5)

Yeah... I have a 160 thermo and the car is tuned to run at 190. Adjustable what, when, how, why? huh?................

oange ss

iTrader: (50)

with increasing EPA mandates,i dont know why they dont use an electric valve controlled by the PCM to fine tune areas of need ,where as now the mech style leaves alot to be desired when it comes down to control and repeatability...

mistermike

Davies-Craig in Australia make an electric water pump that can be electronically controlled. You gut the stock pump and remove the thermostat. Some Ford guys have used these with good results, but I don't know of any LS guys that have tried one out.
http://www.daviescraig.com.au/main/display.asp?pid=47
http://www.daviescraig.com.au/main/display.asp?pid=56

andereck

The thermostat would have to have an active control loop because the mechanical stat is always responding to water temp changes. There aren't many parts more reliable than a wax pellet thermostat.

I however like the spirit of the idea. Keep 'em coming.

squealingtires

iTrader: (14)

Technically speaking: an adjustable thermostat for the automotive world is identical to most modern home thermostats --> Based upon temperature and a commanded setting the valve maintains a particular position.

joecar

I have thought about drilling/tapping the TS housing and inserting a bolt with locknut...
The end of the bolt would meet the end of the TS...
Turning the bolt in lowers the TS open temp, turning out ups the temp.
Leakage is a problem... if the end of the bolt were smooth, you can have a seal.

Steve Bryant

iTrader: (1)

joecar,
What you are talking about could be done with a thermostat and is done for all kinds of pressure regulators for gases and liquids. For instance the standard GM and aftermarket fuel pressure regulators work in this way.

squeelingtires,
I understand your goals. However, for street driven vehicles, the thermostat is set up to regulate between about 180 and 190 degrees F for the reasons you mentioned initially for the hot condition. The cooler running thermostat (like some of the 160 degree units) that HyperTech and others sell would be OK for the summertime and terrible for the winter. How would you propose to control the thermostat? A switch inside the car, an adjustment screw on the thermostat or how. When would you want to go to the cool mode and when would you want to go to the hot mode?

Steve

andereck

No, its not. The home thermostat operates much like an electric fan switch. The home thermostat causes the furnace or ac to operate at a fixed speed until the temperature threshhold is reached and then it shuts off.

The automotive thermostat is constantly regulating the flow of water to maintain its set temperature. Under low load conditions the thermostat will restrict the flow more to keep the heat in the engine metering the coolant that is allowed to leave.

Under higher load the flow increases via larger orifice to let more coolant to circulate through the system due to more heat being put into the system.

nfernandes

What if they make it into the PCM were there is an electronic controlled thermostat and the PCM adjusts timing and electric water pump to maintain it's most thermo efficiency. So engine will stay as hot till it detects detonation, then it will start by adjusting the temperature and timing till it reaches the thermo efficiency. This can be done in open loop mode....Nuno

MeentSS02

iTrader: (11)

This couldn't be done in open loop...that's the very nature of a feedback loop. You'd be using the knock sensors as the feedback sensor, and feed that back to the PCM for action, so this would be a closed loop operation.

Doing it via the knock sensors wouldn't really work...by the time you've detected knock, you are too late with something that is slow to react like the cooling system. That's why the PCM removes timing...that is nearly instantaneous compared to cooling the water/antifreeze mix in the engine.

While this idea has merit, you'd never sell it to the EPA. They would like your engine to run nice and warm so it pollutes less. It is only us hot-rodders out there that want our engines to run cooler for better performance. This would be strictly an aftermarket venture, and as soon as the EPA found out about it, they'd probably throw a ****-fit much like they did with O2 simulators.

squealingtires

iTrader: (14)

I'd like to go into cold mode any time there is the added risk of WOT detonation (Nitrous, hot summer weather, bad gas, etc)
Hot mode all the rest the time, just for the environmental factors and fuel economy and not to mention keeping the oil clean.

You're right. That probably wasn't the best example that I could have given but I wasn't feeding everybody bull either. My home furnace/thermostat system operates at various levels; both the furnace and blower speed change depending on the temp setting and actual temp. The further these two values are apart the harder the system works to close the difference. Many homes are "on/off" types of systems so my appologies for the confusion.

MeentSS02

iTrader: (11)

Essentially, I think you'd be just as well off swapping to a warmer t-stat in the winter when you won't be using things like nitrous (due to snow, cold roads, etc) or dealing with the summer heat, and then putting in a cooler stat in the summer when you will be doing things like that. It'd be much easier if you could just do it via the PCM, but I think it would end up being an *** pain and a half to make it work and reliable. Definitely a good idea though...

Somewhat off topic...are you the one around here running a 402 in the T/A?

buffman

iTrader: (9)

squealingtires, Oil temps and coolant temps are not the same. They are related of course, but are not the same. Speaking from experience on my LT1, when fully warmed up (15+ minutes) my oil temps (read oil temps ) are a full 40 degrees higher than my coolant temperature. The LT1 is no LSX, but I'd have to wager the oil temp to coolant temp matter would be the same: Oil temp always peaking higher than what your coolant temps are.

Ferocity02

iTrader: (60)

Changing when the thermostat opens DOES NOT AFFECT THE ENGINE'S RUNNING TEMPERATURE!

The only thing it changes is how long it takes for the motor to heat up. I've explained this many times and no one seems to get it. The engine's temperature depends on the efficiency of the cooling system(the radiator, fans, settings, etc...) If you want to make your car have an adjustable running temperature, then run a low or no thermostat and somehow have adjustable fan settings. Doing that without pissing off the PCM may prove to be difficult.

Steve Bryant

iTrader: (1)

Ferocity02,
I disagree with you. If a vehicle has a radiator with more than adequate cooling capacity and adequate airflow through that radiator, the thermostat temperature set point will determine the temperature around which the engine coolant temperature will regulate. The set point determines both when the valve in the thermostat will begin to open and close again. What you say would be true only if the cooling capacity of the radiator were inadequate for the BTU production of the engine in given ambient temperatures and operating load of the engine.

If what you say were true, no truck diesel engine would ever come up to normal operating temperature in the colder months.

Steve