Hatzenbach

Thanks for all the input.
So here's my plan
1) I'll change the oil this weekend
2) I will no longer trust the Porsche gauges, but will monitor oil/coolant temp via AIM Solo-DL (ordered CAN cable from Peter Krause)
- if oil goes over 250 or coolant over 225, i'll pull into the pits
3) I will double check the radiators for debris
4) add water wetter to coolant
5) I will not install the PDK cooler yet, my PDK is still under warranty (I am on my 2nd) and I don't want to void it

anything else?

mark kibort

only if they do tests at that temp range and most do not . But yes, that would be one way to compare. Blackstone does a good job of listing what is in the oil and some flashpoint values, etc... but it doesnt reallly select a temp and run a battery of tests..... seeing low oil pressure at track temps is a clear indication that the oil is breaking down.. its that simple. if you care to fix that, you can change oil brand or go to a heavier weight (with some caveats)

177mph

Sounds good. Have fun!

bpu699

Folks that praise vr1... Are we talking about the vr1 sold at autozone? I know they sell vr1 for racing, but that's mail order...

I also see folks praise amsoil.... Are we talking the stock 20/50 amsoil sold at Napa? Or is only the top of the line racing oil considered exemplary...

CosmosMpower

I don't like anything over 255 personally, will slow down or do cool down laps if needed but I've never had to in the GT3 even in 105F air temp conditions.

rbahr

Does your C4s have all 3 radiators?

I can tell you that I have done 45 min on track at a reasonable pave in 90deg amb. with no problems with heat. I would guess that something is a bit off.

In addition, loose the antifreeze mix, water with WW is your best choice to loose heat, specific gravities and all that...

I have spoken with Redline about engine oil temps, and was told that their oils (not certain which one) can handle the temps, I also recommend a UOA after the fact.

I am guessing that you run a 20w50 oil?

Ray

mark kibort

My experience has been the 15-50 racing oil (RD50) from Amsoil AND Redline 15-50.
VR1 showed similar , but not as bad viscosity break down as mobil 1.. changing out to amsoil racing solved that issue.... also redline was fine too. (im sure there are others..... VR1 and Mobil 1 are not )

mark kibort

UOA after the fact will not tell how the oil performs at these high temps, it will tell you if there are indicators that there is engine damage or wear and if the oil is clean enough to continue to run again.

winders

Sure it will. Oil analysis will give an indication of what is happening to the oil while it is in the engine. If the viscosity is not in the expected range, and there is no fuel in the oil, most likely the oil got too hot.

docwyte

I wouldn't sweat those temps at all. Even with a cooler I'd regularly see 280F+ on my LS and it was fine. My Audi 2.7T would see 270-280, never an issue. My friend with a C5 Z06 and no cooler regularly sees 320F and his motor is original, never opened and fine.

Lots of doom sayers here. Yes, a cooler would be nice and if you have the money to add one I would. However if you mostly see 250F and rarely see over that, I'm not sure I'd run out and buy one immediately.

If you come into the pits when you see over 250F you're not going to be out of track very much....

Hatzenbach

Q: Does your C4s have all 3 radiators?
A: Yes

Q: In addition, loose the antifreeze mix, water with WW is your best choice to loose heat, specific gravities and all that...
A: Good to know

Q: I am guessing that you run a 20w50 oil?
A: 0W40

177mph

Great thread. We have one poster who won't go out if his temps go over 200- and another who knows a guy who runs at 320. Gotta love rennlist

ProCoach

CosmosMpower

I wouldn't just pull into the pits, do one or two cool down laps with minimal WOT to cool down the engine.

Mahler9th

Here in the U.S., we have some of the top engine builders in the world when it comes to performance and racing applications of the Porsche air-cooled flat 6. Experience and expertise are a part of this. They won't all agree with each other when it comes to oil types and temperatures, et cetera.

We have quite a few of these folks in my geographical area, and when you expand that space to include folks "in the known network," the list gets pretty big. I'd like to think that any of them would be a great checkpoint on oil and oil temp in a range of cars used sporadically or frequently in performance track driving or racing.

We also have quite a bit of expertise in the PCA tech world, including folks like Reiser.

We have similar resources, in the Porsche horizontally opposed water-cooled world.

Some of the air-cooled and water-cooled resources are the same persons.

Few if any of these folks can be found in these forums.

One non-local resource I might ping about oil temps is Charles at LN Engineering. I spent quite a bit of time with him on the phone a few years ago. I found him to be gracious with is time and learned from him.

There are plenty I can think of just sitting here at this keyboard.

If I were in the OP's shoes, I'd start by contacting engine builders familiar with the engine type and application.

Strange as it may seem, during my time with this "hobby" (30 years now) I have found engine builders to be extremely helpful and forthcoming regarding best practices for engine longevity and health, despite the fact that longer engine life is not always in their best financial interests.

Engine builders. They guys and gals that take the engines apart and see the effects of oil types, maintenance intervals and temperature. I like to target the best possible resources when it comes to questions like this.