Extreme Oil Temperature 74' 2,7s

[wullie]

Hello all,

recently I took my US- 1975 911s to Germany and went full throttle on the German Autobahn.
Guys, I love the Porsche beyond 3000 rpm

But going around 6000 rpm for about 5 minutes the oil temperature went up to 300F!

I got nervous and slowed down to cool the engine.

Is that normal? Oil level was OK, I do not have the front fender oil cooler, just the Behr side oil cooler.
Of course I want to avoid any engine damage.

If it is not normal?
What would be your recommendation for improvement?

Regards from sunny Germany

[kach22i]

Originally posted by wullie
But going around 6000 rpm for about 5 minutes the oil temperature went up to 300F!

I think a pulled head stud may allow super heated air into the top of the cylinder and cause melted piston heads and higher than normal engine temps.

I'm no expert, please use the search function and research the topic, I hope I'm wrong.

[Jim Sims]

Yes, I would expect those temperatures after driving at 6000 rpm in warm weather. How clean is your engine (cooling fins) and engine mounted oil cooler (air side) and the outside of the fender mounted oil tank? If they are dirty or clogged then cooling will be impeded. Also, is the engine sealed for proper air flow (rubber around sheet metal in place and spark plug wire holes sealed?

However even if you do the above you will want to add external oil cooling to continue cruising on the Autobahn at those speeds; you should add a Carerra type external oil cooler or equivalent to the car.

Has your car been given a "German" inspection yet?

[wullie]

Hi,

thaks for your quick replies!

The engine is 'clean' such as the oil tank, the cooler ribs etc. Also the wind guides around the engine should be OK, but I'll double check.

kach, may be you are right, because the Idle Speed screw to adjust the air supply is comletely in to reduce the idling speed. I never got the engine under 1000 rpm. This might be related to bypassing air..

Jim,
yes the car passed the german TÜV inspection. That was quite some discussion but I got the 205/65R15 instead of the 185/70VR15 and the SSIs including the ANSA exhaust into the papers. Of course the Lights needed to be exchanged as well..

It is soo much fun to fast

[Jim Sims]

Have you experienced the wave of lighting brake lights wreathed in blue rubber smoke moving towards you? Or driving 75 mph in fog with 50 ft visibility by following the "Nebel" light in front of you? Sometimes the Germans are just nuts.

[wullie]

No. not yet ;-)

But you are right, some people are fighting their personal war on the left lane. Who is faster, who is 'pushing' another one out of the way?
But I have to admit, Just hours ago I was also out there to go 140 mph. With that old car a real experience. And I was kind of wind shadowing with a 993. Maybe some 50 feed distance..

Crazy? Maybe. Fun: oh yes..

[david lipman]

300 degrees !?

what are you at in the highway in the US? With the same setup as you, I was at 190-220 depending on speed and ambient. This is not at 130MPH though : )

[dd74]

My old 2.7 once or twice got up to 300 in completely stopped freeway traffic. It was a stock 150 hp motor with CIS, which afterward, ran fine.

The thing about these engines; heat doesn't necessarily damage them. What instead happens - as with any engine, really - is after a certain temperature - I've been told 200-220-degrees, maybe a bit higher that they simply begin to lose power.

[safe]

Maybe an oilchange would be in place after any longer visits to 300F.

[k9handler]

While I had my 2.7 in the car and the mocal cooler I could run at 5k rpm all day long...but at 6k the temp would rise however I backed off at 250 degrees. I am in the Kaiserslautern area if you would like to meet up for a chat and maybe a cold beer.

[911pcars]

6000 rpm for 5 minutes in high ambient temp. is a long time, especially w/o an external cooler.

The rough rule of thumb is that 2.7 engines and larger need an external cooler.

Excessive oil temperature is a direct reflection of the temperature of engine parts.
The damage from excessive temperature is two-fold:
- loss of oil film strength resulting in metal-to-metal contact
- Dimensional growth between overheated, close-fitting parts; dangerous if the internal part grows faster than the external part. Scuffing at the minimum. Seizing at its most extreme.

Sherwood

[wullie]

Hello all,

thanks a lot for sharing your knowledge with me ,-)

I guess the best way to ensure a smooth engine temp is the front cooler.
What stock system (model year) would you recommend?

And maybe there is someone out there who wants to sell the coller, oil lines and stuff..

Regards,

wullie

[Miguel Antonett]

You're right, the best way to solve the hight temp issue is with the installation of a front valance oil cooler. Do it right the first time...

[dd74]

I saw some oil lines for sale on Classifieds a couple days ago; you should look there.

I was told OEM oil lines are best, because they tend to fit better than aftermarket.

But if I were to go aftermarket, I'd probably shell out for Elephant Racing's oil lines and cooler set up. It's a very nice kit, and very modern.

You should get a fan as well though I can't remember if Elephant Racing has one with their external cooler kit.

[Joeaksa]

Safe is correct. After the oil has seen temps this high, I would change it out. Look in Zweite Hand for used 911 stuff or on Ebay.de and I would try to find a 1984-1989 Cararra system if you can.

Until you get a front oil cooler I would limit my temps to 230-240 or so, and try to run syn oil in the car. They can handle the higher temps better than dino oil.

Where are you in Hannover? I used to parachute around Meissendorf, just NNE of Hannover. Lived down the road near Osnabruck. Nice area and loved living in Germany. Make sure you go to the CEBIT, the electronics show in Hannover in Feb or March.

Tchuss,

Joe A