I have the Z-51 package which includes an engine oil cooler. What is the normal Temp. range for engine oil? I have seen it go as high as 212 degrees. Is this normal? What Temps. are you seeing?

 

But remember it is synthetic so it alone without any cooler should be sufficient.

 

Same here ... that is quite fine

 

216, seems to be normal, for me.
been as high, as 238.
have been told, that it can go alot higher, without any concerns?

 

My C6 Z51, with under 1,000 miles on it, runs between 210 and 225 oil temp when warmed up, depending on outside air temp (usually high 80's to 90 here) and how it is driven. Water temp is in the 190-210 range, oil pressure 40 to 50 PSI, depending upon RPM, 25-30 PSI at idle.

 

As long as the temperatures stay under 285dF your oil is viscous enough to protect the vital engine parts even under the most demanding conditions of track use. Some might push this 285dF to 300dF and I won't quibble with them.

Oil running at 212 is actually too cool for best power and protection.

 

the magic caution number is 260* When the oil temp gets above that time to slow down and cool down. Yes the synthetic oil can take those temps but the internal engine componants can not.

The longer the oil stays at elevated temps the viscosisty drops like a lead balloon. 20 to 30 min run sessions at or above 260* is too long. That is why there are oil coolers on the Z51 and many of use oil coolers on the C5s on track.

I agree 212 to 250* is the ideal oil temp during hard running.

water temp 205- 220. It is also a good idea to get rid of the anti-freeze and use plan ol distilled water and a water wetting agent ro the water pump lubricant. Water has far better cooling propertiers the ani-frieeze, assuming you live in areas above consistantly 32* F

 

I'm seeing water temps that stay around 198, regardless - and oil temps between 220 & 230 when warm (bone stock, city/hwy driving).

You're saying NO ANTIFREEZE (with it's attendant anti-corrosive properties), just plain distilled water?

I dunno about that one. Anyone else care to comment on this? Since I live in S. Fla, the odds of me ever seeing a sub 32 air temp is minimal.

Regards,

Rick

 

Thanks everyone ! I feel better knowing the cooler is doing it's job.

 

First of all, my Z51 car ran around 217.

Second of all, do not replace the antifreeze with distilled water. Anti freeze does a lot more than just keep your coolant from freezing in the winter. This may be fine for a purpose built race car driven and maintained by someone who really knows what he is doing, but it is awful advice for a normal street car. Do not forget that water's boiling point is 212. Antifreeze works both ends of the temperature scale.

I can just see you going into a dealer with a siezed engine and telling them that some guy on the forum recommends getting rid of the antifreeze and you took his advice. WARRANTY CLAIM DENIED!

 

Agree, street-driven cars need anti-freeze for corrosion resistance and boil-over protection.

Also, you want your oil temps to get over 212, to boil off any moisture that's found its way into the crankcase.

 

Minor quibble: the viscocity of oil is an interesting function of temperature (like you said) but once the oil reaches a temperature the viscocity stays constant (unlike your sentance could be implied to indicate). So the viscocity drops with rising temperature, but at any given stable temperature, it stays at that viscocity until the longer term variables of evaporation and oxidation take place and move the long term viscocity numbers around.

While Mobil 1 0W30 and 5W30 probably are to thin above 260dF temperatures; there are 5W30 oils that are NOT excessively thin at these temperatures. In fact, the HTHS set of tests were designed to allow one to pick oils for extended temperature ranges like track events. Mobil 1 has a relatively low set of HTHS numbers accross the board: Mobil 1 5W30 oil runs an HTHS of 3.06; while Redline 5W30 runs 3.8 and this is higher than Mobil 1 0W40 oil at 3.6. So you don't even have to leave the GM specified oil weighting band to get oils that are fully up to track duty.

The HTHS test is performed on oil at 150dC = 300dF and under conditions of high shearing forces (think: con rod big ends and cam lobes). And when you are running the snot out of your car (mine anyway), it is the HTHS number that you should use to pick an oil for the track. Luckily there are oils with rather large HTHS numbers that also fit into the GM oil weights specified (0W30 to 10W30).

Unfortunately HTHS numbers are not on the can, so you have to do your research via the manufactures materials data sheets before going to the store to buy oil.

 

Thanks, great info! Do you know of any links of someone or someplace that have already compiled a list of oils and their HTHS numbers?

 

A compiled list is difficult to maintain since companies are apt to change their oil forumulations any time they want. Resently Mobil has thickened its oils by a tad but the only wat to know this is to have had the old MDS and the new MDS side by side (or a good memory).

You can visit "Bob Is The Oil Guy": http://theoildrop.server101.com/cgi/ultimatebb.cgi
where oil is the only topic of the day (any day, any time)