as they are part of the combustion chamber, and don't have a water jacket, hence the oil squirters.

The better heat transfer from the presence of the thermostat is about residency time, or how long the water is in contact with hot parts. Removing the thermostat decreases the residency time, but going to a lower temp thermostate will have the same residency time when both are full open.

Running cooler thermostats for more power is a tried and true method. You just have to do it right.

Matt

 

The fan also operates when AC is on too. At AC pressure of 8 bar low speed and at 16 bar high speed. The fan also operates via the coolant temp sensor on head next to thermostat. Low speed at 221 degrees F and high speed at 234 degrees F and remains on high until coolant temp drops by 7 degrees F, then fan goes to back to low speed(precied from service manual).

Basically a lower temp thermostats wax will be fully melted earlier providing more coolant flow during warm up compared with a stock thermostat. If you're driving in the summer it should be fine but you could have problems like gnatster described earlier.

Jeremy

 

Matt coolant residency will be related directly to rpm and system pressure correct?

That's why sprint up to enduro racers put larger pulleys on their water pumps to prevent cavitation at high rpms and to promote a happy coolant velocity!

Jeremy

 

any faster and the natural air flow does enough....

For those that are curious, put your odometer in diagnostic mode 7.0 (coolant temp degrees C) and run your car and then stop. With the motor not running, watch the temp rise. It goes up quite a bit. The fan will kick on and off as described (the numbers make more sense in C, 95, on slow, 101, on fast, down to slow at 100, off when it hits 94).

What's really the problem here is that those that tune for cooler thermostats don't have the best tunes for power. When Franz was still posting from MTH, he was talking about changing the map set points (this is what makes the codes go away) and actuall changing the fan on/off set points to keep the head temps a bit lower.

Remember, the Mini sets some timing limits and A/F points based on a lot of things, including IATs. Cooler radiator=less hot air on the intake and all the associated stuff, which leads to slightly lower IATs, which leads to a bit more advance.

So, really the problem is no one is offering a power maximizing way to take advantage of the lower thermostat points such that you get the benefits without the check engine light.

Matt

 

im totally in agreeance with this, it can be done, but you have to do it right. But what im also saying is that you could also make more power by running the car hotter, if its done right. Just putting a cooler stat in our car wont achieve as much as it could. properly setting the car up for cooler thermostat is probably alot easier and cheaper than trying to set it up to take advantage of a hotter one.

and ill leave the debate about residency rates alone at this point

 

i dont mean to be an ***, i might be confused, but shouldnt that read less advance? (as in 8deg instead of 10deg). Im sort of used to working with an *** backwards system (my other car actually has vacuum retard rather than vacuum advance, you set the advance and the vacuum retards it as needed, reverse as what every other system in the world is) so sometimes i get my wires crossed, and of course its get complicated by the fact some of them use manifold vacuum, and others use carb vacuum. You want the least amount of advance as possible is what im basing my question on anyway

thanks for the intreguing conversation by the way.

Beecher

 

as in a larger number before top dead center. You do this with slower burning mixtures, or with higher engine speed so that you get highest pressures a bit after the piston starts it's downward path....

Matt

 

i agree with that, but im still not convinced. I guess we will just leave it at that for now.

thanks for educating me (trying to anyway).

Beecher