Oil Temp ? For AEHass

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I guess my original thought was Oil weight should be chosen by normal operating temperature not pressure. If we know our normal around town oil temperature Corvette 205F and Ferrari 180F. Wouldn't you choose 30W for the 205F engine and 20W for the 180F engine, so that you get and approximate 10cSt? And then use a cooler to try to maintain those temperatures.




That is my thinking, however, it also assumes you have a reasonable oil pressure. Ferrari engines have very high oil flow and can probably run a slightly lower viscosity oil. I do not know about other engines.

I would probably use the 200 degree oil thermostat.

You would NOT want to try to maintain a viscosity of 10cS at all times. Thinning viscosity with racing oil temperatures provides for the pop-off oil pressure valve to increase flow. This is very important in a hot racing engine. My later chapters show how this occurs.

aehaas
 
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It is a tight fit on these model year corvettes. To do it right with an Accusump to prevent oil starvation, my mechanic quoted me a tidy sum. An oil cooler should drop working temps by 40 F but I believe that a quality ester like Redline is capable of providing adequate protection even at these elevated temps.




Yes, an Accusump is an option but you never mentioned oil starvation (i think) until now. We recently added a tweak baffle (in addition to the stock baffle) to my oil pan that is said to eliminate the long right hand turn starvation in the car here. If you do not have starvation problem, i think just a cooler should be fine. If you are having starvation problems or if it is a known problem...


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By the way, I am getting R compound scrubs(V710's and Hoosier GAC's) at $75 a piece, that is probably not an an option on the Ferrari's size(what size do you use?)




WOW! Where??? Share the knowledge brother
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i use 225/45/17 and 245 (or 255) 40/17. The rims are not stock (Kinesis Motorsport K27).


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...We need a graph of oil temperatures vs pressures both at normal around town driving and for track driving to better recommend an oil weight...aehaas




As always, excellent advice from aehass.


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Mocal has a couple of thermostats I can use one is set at 180F and the other is 200F. What are your opinions on which thermostat I should use? I am leaning toward the 200F, because that is my engines normal operating oil temp.




My guess is that if 200F is normal for the car, then 200F thermostat sounds right. Also, get the LARGEST connector/hoses version to keep high flow/reduced flow resistace. No need to run TOO cool, just in a safe parameter. As always, aehass is THE GUY for Great Knowledge and Wisdom. Like he said, log your pressure and/or hook it into your in-car data acquisition system. FYI: i use the TraqMate system and hardwired in the oil pressure, temps, and other bits so have multiple times per second sampling of data plus g-forces to see if any changes in direction cause the oil pressure to deviate from what may be considered a 'known good.' Like aehass seems to do, i use thinner than 'normal' oil so keeping the viscosity within a pressure parameter is also dependant on temp range. Again, aehass is THE MAN with Great Knowledge and Wisdom and owe him a HUGE thanks for all his help/research.
 
There is certainly a huge knowledge base on this forum. I learn stuff every day. For our new member here you should have enough to go on and you have some homework. Stick around and adsorb as much as you can.

aehaas
 
My hot oil pressure is 15-20psi at idle. I have no idea what it is cornering hard(1.18 g on my G-Tech)as I am looking at more important things at that time, but oil starvation could be an issue. Most corvettes overfill(non LS7) overfill the sump by 1/2 to 1qt to minimize oil starvation. Call Bob chick at (843)762-7324 with regards to used racing tires. Your sizes are unusual though.
 
Partial Homework assignment complete. 03 Corvette around town driving. Oil cooler and thermostat on the way.

Oil press vs RPM and Temps

RPM Temp. Press.

750 206f 33
1000 37
2000 43
3000 to 53
4000 58
5000 63
6000 212f 65

Going to track next weekend. I'm sure I'll torture test Mobil 1 Ow-30. Going to send it to Blackstone after weekend event for analysis.
 
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Partial Homework assignment complete. 03 Corvette around town driving. Oil cooler and thermostat on the way.

Oil press vs RPM and Temps

RPM Temp. Press.

750 206 33
1000 37
2000 43
3000 to 53
4000 58
5000 63
6000 212f 65

Going to track next weekend. I'm sure I'll torture test Mobil 1 Ow-30. Going to send it to Blackstone after weekend event for analysis.


 
Seems you aren't even reaching the relief valve pressure with the 0W30? You might be able to go thicker then with no reduction in oil flow, especially when the oil reaches the high 200s.
 
If the pressure relief circuit has some resistance then a gradual increase of oil pressure is possible after the pop off is reached. These systems vary a lot.

My guess is that you are approaching the over pressure limit at 4,500 RPM. Whatever oil viscosity you are using is fine for this around town application in my thinking. No oil cooling is needed here.

My Maranello 575's pop off pressure was around 80 - 90 PSI. The engine revved to 8 grand. At start up (75 F) my 20 wt. oil wound give me up to 120 - 130 PSI at 3 - 4,000 RPM. But when the oil got up to operating temperatures it would never go over the 80 - 90 mark. This was because the pop off valve was at the far end of the main oil galley so that high pressure would get oil up to the top end faster on start up.

aehaas
 
Just got thru torturing my 94 corvette with an LT1 at Laguna Seca. 4th track day(460 minutes total track time) on Red Line 10W-40. 291 F max oil temp, 15 PSI hot(291 F) oil pressure at idle, I was still not able to check hot oil pressure at max RPM. I was planning on changing my oil out at 20 hours of track time. I am using the Amsoil EAO filter. I will be looking for your post on your Corvette's UOA after track use.
 
Things were so much simpler when I tracked my 94 25th Anniversary Trans Am. No oil temp, no UOA. Just used Mobil 1 and changed it every 3-4k miles. Its still running fine with over 100,000 miles on it. My daughters daily driver.
 
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