50 weight oils for Corvette track use

[oil_film_movies]

Originally Posted by ZeeOSix

That means the oil temp in journal bearings and in other hot spots like the ring pack is even higher than the 290 F sump temperature.

True, where the temperature sensor resides matters. There was a BMW chief engineer quoted on bitog a while back (can't find it now!) that I think said the cylinder walls heat the oil there to about 400 deg F, and Mobil has always claimed 400 F inside turbo's. So there is likely your peak. Those might be worst case numbers already, so I wouldn't think we need to add much to them for hot racing. Question for Corvette techies: Does it have an over-temperature partial shutdown mode? The BMW engineer I cited above said something about how theirs have that to keep a person from being concerned about the temperature gauge. Off topic, but the Tesla will cut it's amps if temperature gets high. Makes sense in expensive machines like Vettes, Hellcats, any that cost $$$. Possibly similar to what GM did with the Northstar V8: "Supplying fuel to only one cylinder bank in turn, the engine would "air cool" the inactive bank. This technique, combined with its all-aluminum construction and large oil capacity, allows the engine to maintain safe temperatures, allowing a Northstar-equipped car to be driven with no coolant for about 100 mi (161 km) without damage." -- wikipedia

 

[Patman]

Originally Posted by oil_film_movies

Question for Corvette techies: Does it have an over-temperature partial shutdown mode?

I believe that when oil or coolant temp gets too hot it goes into limp home mode (it reduces power, although I'm not exactly sure how it achieves this)

 

[SteveSRT8]

IIRC all late model GM V8's have the over temp protection. I've also been told that most Fords do that, too. In my service vans with the 6.0 there are a variety of things that shut you down automatically. The engine either goes into limp mode or pulls the spark and you go nowhere depending on what issue occurred.

 

[oil_film_movies]

It does look like the cool Northstar V8 method of limp-mode (my last post described) due to overheating is not being done these days. Only references I could find were based on all the reports and class action lawsuits surrounding the Mustang Shelby and Corvettes over heating issues, and it appears like "spark is pulled" is what they do. Seems like when overheating is detected, a phased-in reduction in fuel injector flow commands would work too, depending on how much overheating occurs, just put an attenuation factor on the fuel commanded 90% linearly all the way down to 20% proportional to overheating amount, for example.