i have seen many sites offering a lower temp thermostat than stock. the idea sounds good however the R53 and 56 suffer from carbon deposits and thats no secret. i personally have never had an issue but a mini tech i know says that carbon is common in these. itll cause running and driveability issues. i know that it is important to get your vehicle up to proper running temperature to properly burn fuel and run correctly. people that only go short trips to the grocery store ( in any car ) will have issues. now remembering that vehicles run into trouble not reaching operating temp and that R53 and R56 have carbon deposit issues, is the lower temp thermstat going to cause more problems than any gains you will recieve from it? im not claiming to know the answer but i thought with such a large community here someone would have experience or had done some testing. i like the concept of the lower temp thermostat cause the major issues with getting speed out of the mini is weight and temperature. ( mostly air temp ) is the lower temp thermostat actually a good product proven to be issue free or is it a gimmick pumped out by people who dont understand how a combustion engine operates efficiently. thanks for your answers and opinions.

 

yes the cars build up carbon in the combustion chambers. But this isn't from the car not getting to temp. It's from running rich. Note that it runs more rich in "cold start" and before it gets up to operating temp, so they are a bit mixed, not completely decoupled.

Now, the lower temp thermostats are good products, but you have to watch a couple items. If you get a really cold thermostat, the car may never enter into normal operating mode, and may run even more rich than before! So this can just make things worse. If you live in a hot area, this isn't a problem. If the car never gets to a hot enough temp, then you will throw codes. No big deal, but you will get a code you have to clear.

The best of all possible worlds is to run a cooler thermostat, then get the ECU tuned to expect it. No codes, normal operating maps, and slightly cooler engine. Emissions get a bit worse though, and that's less than ideal.

Matt

 

good info, thanks for the response

 

While I understand Matt's point.

I don't see much value in switching thermos to cost to benefit AND I LIVE IN FLORDA. I think I would opt for an oil cooler before I swapped out thermos.

 

Try running Redline's WaterWetter too!

Perhaps Dr. Obnxs has some data for that product for our MINIs.

Jeremy

 

not being a jerk, but ive never seen any mention of "water wetter" on the side of the mini coolant bottle.

 

Check it out Jhud.

http://www.redlineoil.com/products_coolant.asp

My Dad's been running this product in his hotted up Austin Mini 1380cc and he has no cooling issues even above 100 degrees F while towing his trailer. He does run a GM heater core as a secondary radiator in the summer so he likely doesn't need this product. He also runs an oil cooler that he blanks off during colder months.

I'll be using this product this summer.

Jeremy

 

Lower temp thermostat will make the heater less effective if you live in cold-sometimes country...

 

and I don't have data, cause I just use it as soon as I get the car.

Oil cooler is a good idea, but a lot more complicated than just a thermo swap. I'm not sure of the DimSport crowd, but MTH can tune the car for the lower temp thermostat so you don't get codes.

Matt

 

Yes we must keep our partners/passengers warm and happy!

Another option is to use a 180 degree for the summer months and a stock thermostat (190 degree?) from late fall to late spring. I used to do a similar swap on my lightly hotted up 1275cc Austin Mini. 1 clamp, 3 bolts and a new gasket and you're good. On sub freezing days I also would blank off my front mounted oil cooler.

Jeremy

 

Here is an issue I had with my 180 thermo. It threw a "Service Engine Soon" code and now I have to remove it to be able to smog it.

Also, changing the thermo I have been told isn't as easy as it sounds. once you open up the cooling system to get at the thermostat...the fluid is going to dump....therefore, it needs to be replaced. That cost extra money everytime you need to do this swap. Dr. O can correct me if I'm wrong of course.

 

I was also wondering about the cooler thermostat. i have had one for about a year now, just never installed it. i was wondering if it makes you cooling fan work harder? I mean does it make the fan kick on earlier or anything like that?

 

mull this one over, and let me know what you think. I wasnt going to say anything because im undecided on the topic at the moment. But...

the other school of thought is this

A motors job is to turn heat into a usable power. The hotter the engine runs, the less heat is lost into the cooling jackets, leaving more heat to be turned into power. Pre ignition is of course the limiting factor in how hot you can run the engine, as the hotter it runs, the more likely the chance of knock. Now, without serious investigation into the mini, i cant say for certain that the lower temp thermo, resulting in lower underhood temps would give more power than is lost by running a cooler engine. Since the S seems to have a tendency to knock, i might think that the cooler engine would give more horsepower by allowing less timing advance than what you would loose by loosing heat to do do work. Combined with cooler underhood temps, its probably a good thing.

This or course makes it a bandaid fix, and not a true performace mod. But like i said, im somewhat undecided on the mod, and i was once a firm believer of hte cooler thermo, but in light of the research i have been reading, it sounds like you may want your engine to run as hot as you can, with out ending up with knock.

FWIW.

Dr O, what do you think about all this?

Beecher

 

great info beecher. knock is most commonly caused by running lean. higher cylinder temperatures and fuel trim will be picked up by the o2 sensors and the DME will adjust fuel trim to add more fuel as necessary to lower combustion temps. a normal operating engine burns fuel efficiently and has the ability to change engine adaption values to keep the vehicle in the "normal range" along with the cooling system of course. lowering engine operating temperatures is considered a "performance mod" because you are injecting a slightly greater amount of fuel then on a hot engine. the hotter the engine the more you will produce NOX not knock. the leaner the engine the more you will get knock. my worry is that 10 degrees cooler can inhibit proper fuel atomization in the combustion chamber creating a condition thats more prone to carbon build up. am i right on this or did i miss the bus on this whole thing?

 

Just bounce off of the rev limiter now and then. That'll keep the chambers squeaky clean!

Say no to hot spots!

Jeremy

 

the good ol' italian tune up, eh?

 

If you don't use it you'll lose it no?

Beecher brings up valid points. It's a trade off between a cooler intake charge vs. fuel atomization and proper/complete/efficient ignition/burn of the charge. That's why it wouldn't hurt to rev it up with the 180 degree thermostat now and then to bring up the chamber temps!

Jeremy

 

Coupla things I've noticed when running a 180 degree thermostat.

On track during a session the engine gets just as hot with either thermostat. With the 180 it's not as quick.

When temps to about 50 or less outside on the street the temps never really got warm enough unless stuck in traffic. Kept tossing engine to cold codes. At first we thought it might because I have 2 senders piggybacked on each other. The OEM one was at the end of the line. Changed that setup and placed a really nice Coolant Gauge Adapter from Advanced AutoSports and still was getting the same code. Swapped out the 180 degree for an OEM, no more codes.

 

Just like Dr. O said...if you go with a lower degree thermostat you should get it tuned. When I had my Mustang pushing 500+ RWHP I was running a Superchips 180 degree thermostat and they said it must be in combination with their ECU tune. Before I was able to get it tuned I was throwing codes and the car was running like utter poop because it was out of the ECU tolerance.

 

I read a good little tech article about this kind of thing yesterday. The author stated that a cooler running motor has an increased chance of wear due to water vapor forming in a combustion chamber. This vapor sneaks past piston rings and combines with sulfer in oil to form sulfuric acid. As anyone knows, nothing agrees with sulfuric acid. Here's teh link (great tech magazine, too):
http://motorage.search-autoparts.com...eID=1&sk=&date=

 

produce NOX to knock??? explain that one to me if you would, im not sure what your saying. Dont mean to be an ***, im just confused

running lean is the main cause of knock, but so is hot spots, and and the other leading factor, and probably actually the most common is improper advance. Every engine requires different amounts of advance due to different combustion chamber designs, which alter the speed at which the fuel burns, which of course alters the rate at which pressure rises. Knock isny anything magical, its simply when the combustion temps exceed the flash point of the fuel, or is pre ignited by a hot spot.

i have to go to work, ill continue this when i get home tonight

Beecher

 

Bah Humbug!

Do one of you lower temp thermostat advocates want to explain how they make any difference once the temperture causes them to open and the system reaches steady state at a temperature above the opening temperature? Everything else in the system is the same - heat from engine, radiator, etc. - so there's no way you'll get a different steady state temperature.

 

there are lots of load and use combinations when it's not fully open. For all of these use cases, a cooler thermostat results in a lower over all temp. On the track, I too noticed that the temp difference was little, if anything at all. But this is at full load for very extended times.

This in itself is a bit problematic, as it would mean that the temp of the coolant is set by many things OTHER than the thermostat, and this would mean that under load, the temp of the engine is pretty much uncontrolled, a very bad thing. Higher ambient temps (read Phoenix in summer) would have a corresponding higher coolan temp.

now, my temp logging is only via the dash display (odo in diagnostic mode) so it's from the temp sender on the head. I haven't logged temps from output of the radiator or the like.

Also, the reference about much cooler engines and not clearing the gunk out of the oil can actually happen if the engine isn't pushed (there are photos here of gunky oil that cleared up with hard driving). But one has to remember that there are places that are much hotter that will vaporize the water if driven hard, like the under piston oil squirters. Really, it's a trade off, the decreased stresses from cooler oil (better lubricating) vs the increased problems from not vaporizing all the crap in the oil....

Matt

 

So it sounds like the best bet is to try and make the OEM setup as efficient as possible........keeping coolant fresh and using water wetter to assist.

 

i might as well throw this out there FYI, but a thermostat actually is actually used to heat the engine faster, and then to build pressure in the motor, and not to keep it cool, so yeah, on a track, i would see why the overall temps would probably be about the same, but under normal driving, the temp should be kept lower. i belive our stock thermo is 210 also, i had seen someone in here say 190, but im sure its 210.

oh and Dr O, the head is the only place that the temp really matters, its the hottest spot of the motor, or at least it is in engines where the water rises from the bottom of the block, and leaves to the rad from the head, i would still assume the head would be the hottest spot, and the temp would be more even across the engine when it enters the head first. That is always a good thing.

Now, i should clear this up. Im not totally discounting that a cooler thermostat in our car would produce more power. Im just saying that temp isnt the problem, knock is.

but we can beat our heads against the wall all day if we want. Like i said, there is 2 schools of thought (kind of like how to set up swaybars), and either is likely to work just as well if performed correctly. But there is more to it than just a thermostat.