M60 T-Stat, use 95C or 85C one?

[bubba966]

Can't say I'm too happy with the M60 using a 95C stat as that seems a bit high to me. Wondering if BMW has a lower temp stat I found one available for the M60 Gulf Version that's an 85C stat (part #11531729720).

Anybody use the 85C stat in their M60? If so, how's it run? And is the software in your car stock or not? Having the 93 octane E.A.T. software in the car and seeing how much more power that produces I can't help but think that the 85C stat would be a good idea. Should help the cooling system last a little longer as well I'd think.

I'd just buy one and try it, but the 85C stat costs about 4x what the 95C stat does. So I don't really feel like going out and dropping $100 on the 85C stat just to find out it's not a good idea...

[yaofeng]

I don't even remember what I used. But based on your description of the price differential I must have installed the cheaper one. I don't seee anything wrong with it.

[winfred]

the 95 should be ok, it's cooler then the later v8 thermostat, they went to a 105 and typically cycle between 228-236 when everything is working

[bubba966]

I'm not having any problems with the 95C one. But a cooler running engine should be easier on the cooling system. And as I've been having some of that crap out on me in the last week it's been making me think or a cooler stat.

Cooler running engine usually = more power, while a hotter running engine = better emissions. I could care less about the emissions as my car runs stunningly clean. Any slight drop in emissions from running a cooler stat wouldn't make any difference when the emissions test comes around.

Mostly wondering if the 85C stat factory cars had any other provisions for that stat temp. That's a lot bigger difference than the M50 stats that are 88C & 92C. S38 stat is 79C.

[yaofeng]

Hotter running engine has more power.

[mottati]

bmw bumped up the thermosat to help with the nikasil issues, cooler temps damaged the cyl walls more quickly. Should be fine with an alusil engine. The M cars run 79C thermostats (s38 and s62, maybe others).

[Jon K]

Hotter running engine has more power.

actually a colder running engine (between 165 - 185) has more power, but higher emission output.

[yaofeng]

Read this and tell me if you still think a colder engine has more power.

http://www.grc.nasa.gov/WWW/K-12/airplane/work2.html

[bubba966]

Read this and tell me if you still think a colder engine has more power.

http://www.grc.nasa.gov/WWW/K-12/airplane/work2.html

There's a lot more to the entire process of the internal combustion engine than just one thing like that. Not saying that's an invalid fact, just that there's a lot more that effects the entire outcome than just one thing like that.

The temp range Jon mentioned has been proved to be the best temp range for producing the best power. And just as he mentioned higher temps reduce emissions outputs.

Exactly the reasons why cars are now running in the 200-210 range (to meet those even tightening emissions standards). And there's a good reason why the boys in the M Division put 79C (174F) stats in the M series motors (who puts out some of the best power to displacement NA engines in the world).

Don't believe it if you don't want to. That's fine by me. Mottati was good enough to remind me of why BMW bumped up the running temp of the M60 (I'd read about that so long ago I forgot). And Fetch was nice enough to give some experience running the 85C stat.

I'll run an 85C stat at some point. And you can continue to run your 95C stat. And we'll both be happy.

[yaofeng]

Of course I realize temperature is not the only factor. Many things come into play and are affected by temperature, mechanical clearance, seal life, lubrication breakdown, etc. Every engine is engineered to operate in a range of set temperatures best for the performance.

A hotter engine is a direct result of hotter combustion temperature. Does it produce more power? Of course. This is from a pure thermodynamics point of view of gas combstion. Is it good for the endurance of the engine? If it veers away from what it was designed for. No. It may or may not even produce better performance all things considered.