Was 180' now 210' ish

[911s55]

Went for a nice long last day of spring drive today around town and noticed warmer operating temp than last year. Car is 71' with a 74' 2.7 with webers, ambient temp today was mid 70's. Here is what's different from last year. Changed exhaust, Bursch to painted stainless Leistritz (both 2 in 1 out), plugs from Bosch W5DPO to NGK B7ES, oil from 20/50 to 15/40, which I ran two years ago without issue. I'm aware of the heat increase with stainless exhaust and better cooling with higher grade oil, but 25 to 30 degress up seems a bit much. Whatta ya think?
Thanks, David

[ToddM]

In your subject line, I thought you were referring to your body weight and how your fat ass is ruining your HP to weight ratio... that is my problem, anyways.

[911s55]

Good one!, No, still narrow body like my 911, And I do prefer my women like my car, "Thin and Proper" not "Fat and Aggressive", but to each his own.

[leverpuller]

It could be something as simple as the humidity. My 82sc has been running cooler this year, I have no clue as to why....I read an article where they were testing the oil filter cooler....the test car was a corvette. the interesting part was the starting temp without the cooler ring(oil temp) was 224 degrees. I try not to pay too much attention to the temp cause it spoils a good drive looking down all the time....what do you think?

[ToddM]

Just go out and get a nice fender mount cooler with fan. I was high 90's last week and with my 3.6 and the AC blasting I was just over the first bar which was the hottest I've ever seen it run. I probably have a better chance of one of my wheels falling off.

Of course now that I said that it will probably overheat and catch fire tomorrow.

[Tyson Schmidt]

Are you running the stock points triggered CD?

If so, you should check the ignition timing. The rubbing block on the points wears down, which in turn retards the timing gradually over time. Retarded timing increases engine temps.

Oh, and check the fan belt condition, and tension.

[911s55]

Thanks Tyson; No points, Pertronix and belt is 2 yrs 6k mi, but will check when I get home.

[azasadny]

My '74 with 2.7 and Webers never gets above 190 degrees but I have the external Carrera-style oil cooler and I run AMSOIL 20W50 synthetic oil.

[Tyson Schmidt]

Well then maybe take a look at the top of the engine for mouse nests. Just pull off the heat ducts on either side of the fan and look in with a flashlight.

[BlueSideUp]

Tyson, there is a lot of debate about this but how do you feel about the Pertronix vs. points debate?

Do you think the change in oil viscosity could account for his change in temps? 20/50 to 15/40

[Drago]

Did you see this thread?

Lower engine temps 20 degs for $20.....

[911pcars]

"I'm aware of the heat increase with stainless exhaust and better cooling with higher grade oil, but 25 to 30 degress up seems a bit much."

You have a lot of variables described in your first post. In regards to stainless exhaust, it's not the material. It's the exhaust temp.

Why do you think 15-40 is "better" than 20-50?

However, these could all be unrelated to your increased oil temps. Check the basics first to rule those out (compression test, ignition timing, etc.); also the rodent nest is a fairly common one especially for winter-stored vehicles.



Sherwood

[Paulporsche]

Are those 2 plugs the same heat range?

[T77911S]

let the car idle and see how hot it gets, drive and see if the temp comes down, if does not come down when moving, the T-stat is bad. just had to change mine.

[ianc]

Just a guess, but if you changed your exhaust, it may have less back pressure than your old one. If that is the case, your mixture will lean out due to the increased air flow. Check the mix on an EGA, or try richening it up a little. Good luck,

ianc

[Paulporsche]

When I went from stock to an SSI exhaust I had to richen the mixture slightly. A too lean condition can lead to higher temps. Whether they account for 30 degrees or not I don't know. It might be a combination--the plugs, the oil, the mixture, a loose fanbelt, the atmospheric conditions, the exhaust, all together.

[911s55]

Rodent factor zero, belt in good shape and adjusted, while the Burschitt exhaust was on, the carbs did have a tendency to pop and spit, so I did lean it out quite a bit, will check that this weekend, and which heat range plug would "increase" motor temp, cooler or hotter. Thanks for the input everybody!
David

[911s55]

Got back to my warm running condition today, changed to a hotter plug NGK B6ES, re adjusted carbs, went for a drive and was still seeing 200+. Parked the car and dinked around with other projects, after car cooled changed fuel filter, went for a mixed drive of residential and freeway and VOILA, 180-190 degrees. Old filter was barely 2 yrs and 7k mi, but I guess it was due. Weird thing is I didn't experience any accelleration or idle issues. Gotta check manual for service recomendations, thought it was longer.
Thanks to DRAGO for posting thread link about this, I wasn't sure if I would have success, the responses we referring to injected cars but I"ll take it. PRETTY COOL! Literally.
Thanks to all for suggestions, David

[911pcars]

Why change to the hotter plug? Is that spec'd for your engine?

Sherwood

[Formerly Steve Wilkinson]

Oil shouldn't stay in longer than a year no matter how few miles you go, and I'm assuming you didn't change the oil for two years if you didn't change the oil filter for two years.

I also assume your reference to a "fuel filter" in the first para should read "oil filter."