got to 258 today during an extended stint of agressive driving; at what point does them temp become worrisome?

 

The mobile 1 oil in our cars shows to not burn until it reaches temperatures of 375 degrees, before burning off. Regular motor oil shows burning off at 275 and up, and thickening when exceeding temps of 245. So, 258, which my car has gotten from time to time, is no big deal for our synthetic.

 

Other folks will say that anything over 265'F is too warm for our 5W-30.
My thinking is that the old Bragg-Smith school (now Spring Mountain) was running 5W-30 in their C5's even during the Nevada summer, and had no engine failures when I took their course. I haven't heard about them blowing up any C6's, either. I think the second radiator fan is commanded to come on at about 300'F, that might be a good place to say "enough.".
If someone blows an engine under high oil temp, maybe the temp caused the problem, mayb not. But if about 10 cars (Spring Mountain) are running high temps and not blowing up, that sounds significant to me.

 

I've seen 282 before!! Forgot I had the AC on....

 

258 is fine. I would worry about it if it got to around 285 or higher.

 

I saw 288 at the track on a very hot and humid day. If you short shift one lap it will come down in the 260's pretty quick. Now if I could get my over heated tires to cool down as fast, I'd be doing good.

 

My '02 Z06 would see close to 300 after 30mn of hard driving. I would back off as soon as it passed 290. Didi this repeatedly with zero problems. My C6 seems to do better...it never passes 275 or so under same conditions. So bottom line, I wouldn't worry about it.

 

Until it gets to ~300. Time for some cool down. Shouldn't hurt the synthetic oil itself, but the engine is what is making the oil temp rise. For oil to get to 300, the metal is a bit toasty.

 

260 is the magic number to slow down.

YES the oil 5-w30 can take 300 * for short periods of time, but the internal engine componats can not.

Consistant high temps need oil coolers and 40 or 50 wt oil

 

Hmmm, 260 - 300 is a pretty wide swath.

If my Z51 hit 258 after 30 or so minutes of agressive driving, how in the world could you do a track day without added a larger cooler?

maybe 10w-30 or 10w-40 is a better route to go.

 

That is the one major draw back of the corvette, oil cooling during racing or track days. thicker oil will help but not like an oil cooler.

Any one who does track weekends will tell you put in an oil cooler and trans cooler. I put mine in after my second track weekend

 

So even though the Z51 has an oil & trans cooler, you are saying install larger ones for track days?

 

Z 51 HAS IT COVERED

 

I saw 278F at a recent track day when temps were in the low 80s and skies overcast, very humid. Just leaving the car in 4th for one lap did pull it back into the low 260s, but I think if I make a habit of track days (not likely after all the rock chips), I'll add a better oil cooler than the stock Z51 piece.

 

the z-51 needs a real oil cooler

and alot of masking tape for track days

 

True, but just because those motors didn't experience catastrophic failure (ie: blow up) doesn't mean that they weren't experiencing greater wear/long term damage either.
And this part of why I don't use Mobil 1 5W-30 as well.
This is the point where the oil discussion threads tend to turn bad by the way.

 

You should be in good shape, just watch those temps.

and yes a few of us have head and seen engine that suffered from oil starvation and untilmitly failure do to excessive heat and useing oil too long.

No matter what oil you use in most cases it can not take high heat more then 240-260* for very long.

To give you an example: I run 15-17 HPDEs a year ( new business has kept me to 10 HPDEs this year)

I have an oil cooler, accu-sump combo ( 10 1/2 qts) and a trans cooler.

I use 15-w50 M1 most of the year oil temps are consistant 250-255*

Change the oil and reset the DIC M1 100%

after first weekend or about 200-250 miles, DIC says oil is down to 70%

second weekend, again 200-250 miles, minimal street miles of may be 15-20 miles, DIC oil is down to 30%

I send a sample evey other oil change to two differnt oil testing labs

Both labs come back with you might be able to do one more weekend but your oil change interval is about right.

I also send oil samples in from my tow vehical and my wifes vette. Both go about 5000 miles on 10-w30 M1, I live in Raleigh NC so I dont have to worry about cold starting.

There is not a problem with useing 5-w30 or 10w-30, just that you will need to change the oil soon after a track weekend of high oil temps240* +. The heat does break down the oil very quickly
WHen looking at oil look at the HTHS rating.

and ppl who tell you NO it does not have not been consistanly to the track or say "the Manual says" have never had their oil tested from exessive heat use of racing or track days.

 

So when exactly do my Z51 coolers kick in????My oil temps seem to be the same range as all my other vette's which were regular vette's.What do the coolers do exactly??

 

The oil cooler is on all the time. Oil is circulated from the pan to the oil cooler back though the oil filter and into the pan.

The oil cooler or small radiator allows air to pass though cooling fins and keep the oil temps down.

On the Z51 the oil cooler is an internal oil cooler with is part of the radiator on the right side.

Sperate or intigrated does not really matter. I prefer the seperated.

I also use a manual switch, not a t-stat switch, for the accu-sump.

I have a separate oil cooler radiator and sepeate trans oil cooler


Here are some pics and other questions about a 402 and oiling issues

http://forums.corvetteforum.com/show....php?t=1501229

 

So,why do temps not seem all that different from non-cooler equipped vettes?