Low temp thermostats....

[jmatta]

Thanks, Charles. I appreciate all the effort you and Jake have put forth and show it by purchasing your products. Let the sceptics be sceptics; like I really trust what the factory did to butcher these engines, when for minimal dollars, they could have produced them correctly.

Keep up the great work and we'll keep reading and upgrading.

[JFP in PA]

Originally Posted by blue2000s

So on average, the car will run cooler when you mix in all driving conditions. Is there any difference b/w 2 and 3 radiator cars?

The only real difference we've seen, and it is a totally subjective observation, is the three radiator cars tend to return to "steady state cruise" temp levels slightly quicker after warming up in traffic. We have seen that on 2.7L equipped with three radiators and the "S" oil cooler as well as on factory "S" cars. The assumption is this comes from the larger amount of surface area from the 3rd radiator adds.

It was mentioned earlier that there are hot spots in the engine. Do you know how these were identified and monitored? I would imagine they have an instrumented engine out there somewhere?

I first heard about the localized "hot spots" from a Rolex GT team engineer several years back, who attributed them to poor coolant circulation resulting from how the coolant passageways are cast in the M96 style components. As they are capable of running the engines on dyno stands (out of the car), they can measure or use additional instrumentation that is not possible with it in the car. That said, we have used two methods to look at this issue out of curiosity, the first being a hand held non contact infrared pyrometer to measure surface temperatures while the car was being run stationary but with fans blowing cool air over the radiators (to simulate “cruise” conditions), the second was to attach temperature recording strips to various areas of the engine and take the car out for a run, after which the strips are examined. In both cases, multiple areas were noted as reaching higher temps than the coolant had indicated. So it seems real.

This issue, by the by, is not limited to Porsche M96 engines, and is more common than you might imagine. Back when I raced, it was not uncommon to see some really creative "north west passage" external coolant plumbing systems on some domestic engines to get more coolant flow to problem areas. Might not look very pretty, but if it kept you in the race, it was worth it...................

[Topless]

Thank you Charles. Running higher oil temps to eliminate water and then offering long oil drain intervals as a marketing tool is the best explanation I have heard yet for Porsche running 180 T-Stats. Thanks to your research we know this was misguided. Running lower engine temps and changing oil more often has two benefits: The motor runs better and lasts longer. Makes sense to me.

[Topless]

Originally Posted by JFP in PA

This issue, by the by, is not limited to Porsche M96 engines, and is more common than you might imagine. Back when I raced, it was not uncommon to see some really creative "north west passage" external coolant plumbing systems on some domestic engines to get more coolant flow to problem areas. Might not look very pretty, but if it kept you in the race, it was worth it...................

Yep. The Chevy 454 is world renowned for lousy cooling and engine hot spots. Lots of creative engineering is required to keep it cool when building the engine.

[Sputter]

Out of curiosity. Did you find that oil consumption increased with the lower t-stat?

[JFP in PA]

Originally Posted by Sputter

Out of curiosity. Did you find that oil consumption increased with the lower t-stat?

No, we have not seen any increase in oil consumption with the LN stat; and (in fact) if anything would expect that we would see consumption decrease with lower operating temps, not an increase........................

[Sputter]

Why I asked is because with lower temps you might see lower engine tolerances due to lack of expansion. (though at that temp difference it may mean nothing).

Originally Posted by JFP in PA

No, we have not seen any increase in oil consumption with the LN stat; and (in fact) if anything would expect that we would see consumption decrease with lower operating temps, not an increase........................

[cnavarro]

Oil consumption would decrease with the low temperature thermostat, if nothing at all, because the oil will be cooler, thus more viscous.

This is akin to the difference between running 0w40 m1 and 15w50mi in an aircooled 911 - a change as little as that has a huge affect on oil consumption, with the thicker oil using significantly less. My 964 would use 1 qt/700 mi with 0w40 and uses 1 qt/1500-2000 mi with 15w50 m1, for example.