View Full Version : Auxiliary Oil Coolers

02-18-2002, 01:19 PM
Can someone explain the types of coolers used in 72-73 S models, radiator, loop, etc, compared to T's, or E's? Are they suited for hot weather conditions (100 f), with air conditioning? If not, what types of upgrades are required?


Chuck Miller
02-19-2002, 09:31 AM
The 72' came with a radiator type and the 73' came with a loop type cooler. They were both mounted in the same location, however, their thomostats were located in completly different locations. The simple answer as to which model car got one is that they were optional on all 911 models (with exceptions)

I'm afraid I can't answer your AC requirement question, however, ALMOST ALL (one of those exceptions) AC equiped 2.4 cars had external coolers.

What I can add is how my own 2.4 73'-S is equiped.
My S was delivered without an external cooler. It never ran hot, however I new I was going to push it on the road and compete with it on occasions. So, after doing some homework, I retrofitted a 72' radiator type cooler with 74' (later type) lines. The later line locates the thermostat in a MUCH smarter place. The cooler has been on my car for about 11 years. I run in the POC Short Track Series about 4 times a year at Willow Springs in the Southren Cal. desert where it gets over 100 f. After a ten lap session my car is still under 220 F. And street driving it on a cool/cold day it takes awhile (a little too long for me) to get it to running temp. In other words, I have a very cool running car.

I hope this helps, I know their're many out there with other opinions, ideas, and salutions ... jump in

... ps.. the spell check is not running on our site today so please excuse ...

02-19-2002, 09:58 AM
Under "normal" conditions, it seems that an engine displacement of 2.7 is the point at which more heat is produced than the cooling system can effectively dissipate w/o an external cooler. Use this as a point of reference to decide whether adding one is on your "to-do" list. In addition, you should consider other factors that might require one: ambient air temperature, A/C, driving conditions, altitude, etc.

Sherwood Lee

02-22-2002, 12:17 AM
I have seen engines of all sizes and setups either run hot or cold without a cooler. I have seen 2.8 mfi motors run like a ice cube and at the same time I have seen 2.4E motors run far to hot. Even cars that have external coolers I reach my hand under the rocker to see if the lines are hot meaning that the car has gotten hot enough to open the themostat for the cooler. My advise if your motor runs hot then put a cooler on it. However if you plan on track events you will heat it up no matter what it is so a cooler is nessesary. On my 2.7 the cooler is rarely open, only on hot days, during most of the year in Oregon it is closed so the cooler is not utilized, usually on a 50 to 70 degree day it remains shut with the car running at 80C. However the exact same motor in another car runs much hotter and the cooler is always working with the car running some 15c warmer. This engine came apart to investigate the problem and nothing was found and it ran no cooler after the inspection. We even swaped gauges and sending units to verify the problem. Weird!

02-23-2002, 03:30 PM
I have a 2.7 RS engine that runs so cool I put on a 5 blade fan just so it would get up to 180 under normal use. I also have a 3.2 that runs pretty warm--210 even with a front cooler.

02-24-2002, 10:13 PM
Thanks for the responses. Regarding the 2.7RS, is it exposed to hot weather coditions? 90 +, does it have an external oil cooler? what type, loop, radiator and where is it located.
Do you know if the Carreras of 74/75, which had the 2.7 RS engine, came standard with an external oil cooler?


03-13-2002, 06:30 PM
I find that the So. Cal weather is just perfect from an operating temp. point of view. I can pretty much get it warm enough at any time of the year and day. At the extreme summer months 230 is about the worst I see on the gage, maybe 240, usually I'm around the 210-220 range. I am talking 2.7 RS motor driven on the street, with the the Behr fender aux cooler standard on the 72S. At the track would probably be different. I use Mobil1 15W50.


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03-14-2002, 09:26 AM
The very best lubricating oils, even Mobil 1 or equivalent, do nothing to prevent excessive part expansion due to overheating. When this happens, the reduction in operating clearances does bad things to frictional surfaces.

Let's keep our engines within normal operating temps.

Sherwood Lee
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03-15-2002, 01:43 PM
My understanding has been that on the '72 S models, the front oil radiator style cooler was standard...whether the car had air or not. No air on my car, yet it has the cooler, and the cooler is absent from the factory list of optional equipment. I believe that the front cooler became an option in '73, and it was the trombone style. Sorry, have no idea about the years prior to '72.

04-04-2002, 06:59 PM
Guys, Here's an update on my external oil cooler experience:

My 73S (engine type 911/63) with spotomatic does not have an external oil cooler. I have the cardex for the chassis # and it does not mention an oil cooler. So far I have not found any mounting points on the body that might suggest an external oil cooler at some time in the past.


04-05-2002, 07:41 AM
That makes sense. In the 1973 model year, the front fender cooler was an option. It was a trombone cooler in '73, but was not standard equipment, even for the S models.

Jim Dunham
10-07-2018, 04:36 AM
So is there a trombone style oil cooler that will hook up to the '72 oil lines?

10-07-2018, 04:55 AM
I run a 2.0S High Comp. with just the engine oil cooler, even with 35C or driving to the metal on track it does not go over 210F.
However, the oil pump is a big one and am running Motul 300V 15w50.

10-07-2018, 08:52 AM
So is there a trombone style oil cooler that will hook up to the '72 oil lines?

Yes, the 73 RS cooler. The later trombones have different angles on the fittings. Canfield classics makes the correct trombone.

Jim Dunham
10-07-2018, 12:20 PM
Thanks Ed - wow, I have not seen you since 1993 Parade. I see Aase makes them too. I may put in a shunt line to just connect the cooler lines in front until I sort what to do. Running a 3.2L in my '72


10-07-2018, 01:27 PM
The trombone is insufficient for a 3.2. You will need either a 28 tube brass or a later radiator type.

Frank Beck
10-07-2018, 05:54 PM
Sometimes the trombone will do it... depends on ambient temp, whether it has A/C, and driving style.

BTW: The RS loop cooler is available from Porsche.

Jim Dunham
10-17-2018, 04:11 PM
I have the 72 lines mocked up now with a later trombone cooler and it looks like it will indeed work with some minor tweaking and new bracket fabrication. just clears the battery box. I'll run it to completion and post pictures.