oil cooler options

[trond]

4 weeks ago we took the car on a roadtrip on autobahn and Lake Garda in North Italy and we did about 1800 miles. With the higher temperatures, around 90F and much higher sustained engine loading oil temperature increased towards the red. Once in slow moving traffic waiting to enter the San Gotthard tunnel with engine idling for almost an hour temperature came into the red and continued to climb while oil pressure started to drop so it was hotter than it has ever been. Engine is 3.2SS twin spark with trombone oil cooler. At idle I have 3 degrees ignition advance only and AFR is around 13+. Oil was 15W-50 Motul 300V which seem to hold viscosity with temperature better than mineral oils. Oil pipes get hot as thermostat opens and I would have thought it should not overheat at idle. At home with lower ambient temperatures below 70F, oil temperature hardy ever goes above 9 o'clock on the gauge.

My question to the forum is for advice on front mounted engine coolers. I'd hate to spend 1200 dollars on a carrera set up but will if I have to. Is there a more reasonable option ? Have seen the mocal cooler kit offered here which would do it except I want a fan too, and protection against wheel spray and rocks

[winders]

Getting the AFR down below 13:1 would certainly help. 12.7:1 is really as lean as you need to go for a race car and a street car could probably handle a bit less.

The Carrera front fender well setup is nice because it is well engineered and works.

[trond]

OK thanks. Will give more fuel. And keep eyes open for a carrera setup. Appreciated

[ClickClickBoom]

Look up Turbotrol Oil Cooler on the forums. I used one on my “75. Usually priced reasonably . I have one in the shop as a backup for my 28 tube Carrera. The price was so cheap, I couldn’t pass it up. The thing is tough as rocks. What oil cooler is this pls?

[86 911 Targa]

^^^^^
A great addition to our M/Y 1986 was this oil temperature switch.

ON: 205f
OFF:197f.

Made by Nason to any temp you specify.

Attaches to the top of the front factory oil cooler.

You will have to add a relay to the fuse panel.

Best,

Gerry

[grizzfan]

Shipping and import duty may be a challenge for you in Norway, but consider the Elephant Racing Oil Cooler setup. Their website allows you to see the various configurations. They are very good to work with and the company President will probably answer the phone. Call him. There might be a European distributor.

I have a '73 911T with a 2.7L engine that ran a bit hot as they are prone to do. I installed the Elephant Racing right front fender version and later added a switchable fan (not from ER as their model cuts into the right battery box), to the cooler body for around town, slow driving that doesn't allow enough air to pass through it. Very pleased.

Good luck.

Tom

[icarp]

I would also suggest adding another 2-3* of timing advance , ending up with a total advance
of 29* @ 3200 rpm. Timing advance adds to cooling of combustion . I think the Carrera cooler with fan is your best bet for the money . Look for a good used one , that will help with import duty

[trond]

appreciate the feedback. icarp; do you think 29 degrees with dual spark may be a bit much ? My engine runs harsh with too much advance and is not rev happy or in any way smooth at more WOT timing above 20ish. At cruise is another thing. I did find slightly less (about 2 degrees less, to about 19 degrees) around 3500 at cruise lowered engine temperature enough to let us maintain the pace. Just had to being underways and struggling with high temperatures.

[spuggy]

Originally Posted by trond

I would have thought it should not overheat at idle.

The hottest I've ever seen my 930 was idling stationary in traffic. Like 250F, or 20-40F hotter than I've ever seen under boost or at the track. Because when driving, the car is both moving and has RPM - so thus lots of oil flow, lots of air from the fan & airflow over the FMOC from forward motion.

In this thread here: 3.2 carrera operating temp , I observe that with 30C ambient, I pull in from a drive with both motor and oil nicely warmed up and leave it idling - and CHT rises ~45C (from 123C to 168C) and oil temp sensor (in the chaincase) goes from 67C to 85C. In not quite 3 minutes, according to the datalog.

Temperature rise doesn't slow down either. CHTs of 180C are a couple of minutes away. I don't know where the temps stop if you just leave it idling; dino oil starts to break down around 115C, so despite running a Euro full-synthetic (German-made LiquiMoly), I generally wimp out and either drive around the block or switch off.

FMOC, no matter how large, does almost nothing once for you when there's no airflow across the bars/plates. Sure, they will radiate a tiny amount of heat, and will increase the overall oil capacity (which shares same amount of heat over a larger quantity of oil, tending to produce a lower oil temp). But they're designed to shed heat through airflow - simply drive the car, and high oil temps will drop 20-30F within half a mile or so.

Increasing engine RPM puts more cooling air over the cylinders/heads - and also increases airflow over the engine oil cooler. Running the motor up to 2000 RPM or so can drop oil temps as much as 10-20 degrees when stuck in traffic. I have no data for how much this might help with CHT.

Carrera cooler with fan (and ideally a thermostatic switch with a lower set point than factory) is about the only setup that works to control oil temperature for for idling while stopped. I have one that I was intending to fit for precisely that situation. But this won't do anything for CHT.

Originally Posted by trond

At home with lower ambient temperatures below 70F, oil temperature hardy ever goes above 9 o'clock on the gauge.

Thermal runaway; exceeding the ability of the system to regulate the temperature - eg putting more heat into it than it can get rid of. Once that happens, temperatures just end up whereever they end up...

[trond]

I am unused to ambient above 70 and it was stressful to see oil temperature increasing and continuing to increase, with a ferry (or car train actually) to catch. Will avoid warmer countries and similar situations in the future as far as possible. And will get an oil cooler with fan too. Also glad I had full synthetic 300V15w-50 in there.

[Ian Comerford]

I replaced the trombone on my 79 SC with a 28 row brass cooler from a later car. Works really well

[RedCoupe]

Originally Posted by trond

I am unused to ambient above 70 and it was stressful to see oil temperature increasing and continuing to increase, with a ferry (or car train actually) to catch. Will avoid warmer countries and similar situations in the future as far as possible. And will get an oil cooler with fan too. Also glad I had full synthetic 300V15w-50 in there.

You shouldn't have to avoid warm countries. My 964 has handled 116f in a traffic jam in Phoenix and never got much above 220-230, as the two speed fan switched between low and high. My 3.2 Carrera also ocassionally sees hot desert temperatures with no oil temps to worry about. I think the key is a radiator-style cooler with a fan that is either manually switched or has a sensor that turns the fan on at a low enough temperature to keep it running a fair amount of the time.

[David Inc.]

I would often sit in Texas traffic in my SC with a trombone cooler and not go above 250F. If someone is getting into the red idling in 90F weather then something is very wrong.

Edit: Whoa--it was up towards the red while driving on the autobahn? I've done track days in 95F humid weather where I've gone above 250F for short periods but that was with full engine load and only a trombone cooler. At highway speeds (140kph) I could drive all day long at that temperature without going above 220F.

Definitely something wrong.

[trond]

no. At up to steady 100 mpg it is fine, with temp gauge at 9 position. Into the red was after long 100 mph followed by an hour stuck in slow moving traffic and 90F. Never seen the gauge up there before

[spoke]

If you go to a front mounted oil cooler, absolutely put a fan on it. I just added a fan to the oil cooler on my 930 and it made a world of difference in keeping the temps low.

The FMOC could not have been put in a worse place than behind the bumper. There's almost no direct airflow to the cooler; the headlight bucket blocks the top half of the cooler (hence only one fan on the bottom; and the horns are in the way.

[David Inc.]

Originally Posted by trond

no. At up to steady 100 mpg it is fine, with temp gauge at 9 position. Into the red was after long 100 mph followed by an hour stuck in slow moving traffic and 90F. Never seen the gauge up there before

I've been stuck in much hotter places than that with only a Trombone cooler and the AC on without getting anywhere near red. What is "the red" on your gauge?

[lvporschepilot]

The Setrab 44 or 50 row units are excellent replacements and are more efficient than the Carrera cooler.

[Tylermelvin]

I have a 78 915, only in the recent 2 years of the 8 I’ve owned it has it started to have trouble.

I’m now driving in 6500ft elevation** as opposed to the previous 500ft**

I’ve recently had everything inspected and the only response I get is that it’s a standard issue and to get a Carrera cooler setup.

I’m a bit baffled because years ago I drove nearly 1300 miles straight (granted it was during a far cooler season).

I now drive 20 minutes at normal operation and the gauge generally gets less than a slim pinky width awake from RED.

Carbon buildup? Idk

[spuggy]

The trombone/28 row/Carrera coolers mounted in the fender are not usually referred to as an FMOC, despite being sort of up front.

This is a front mount oil cooler:



Without any air movement, the 28 row is apparently the best heat sink, although the bar/plate Carrera cooler is superior once moving again. Carrera w/ fan is the only one that does anything when stationary (as the only one that will have airflow).

Hard to beat a big FMOC once you're moving, simply due to area/placement. Especially if you notch the tub behind it for airflow.

[gumby]

Trond
Off topic..the color of you car is fabulious!