1973 RS trombone fender cooler

[denson]

Jeff Gamroth re-built the motor and built it up. She warms up real fast! I had a regular fender cooler (74-89 cars) installed with the vented cover, but know the trombone is what the car should have. If I convert back to the trombone, should I have any concerns with the motor running hotter than I really want?

John

[popowitz]

John,

I have a '73 S with a 73 only trombone oil cooler. I live in Southern California and my car rarely if ever gets above 210 degrees. Not sure if this is above your expectations but the car runs beautifully and the rebuilt engine has 80K plus miles on it.

-Dave

[RSTarga]

I'd keep the radiator type. The trombone was not sufficient cooling for just about anywhere if driven hard, (except maybe northern europe). The trombone was just a stop gap, to eke[ the accountants happy, measure between the old radiator which rusted out and the new more robust Carrera cooler. I have one of the 28 tube coolers and it is very good too, but probably not as good in all conditions as the radiator type.

[RennTyp]

I've heard that most of the cooling effect from the trombone system come from the external pipes running under the sill rather than the cooler itself! Certainly most racers use the radiator type.

[denson]

I have heard negatives and okay (positive) comments about the trombone. Most comments have been that they are not very good at all and even Porsche knew that. Well, the jury is not out yet. I hope some more people jump in on this thread. I would be less concerned if my rs motor was 100% stock, but it is a 2.8 or 2.9? car and gets pretty hot, rather fast.

[NorthernThrux]

So I've gone through the same process on my 73 911S. This is what I know.

-The car did not come with a cooler according to the 1991 LOA from Porsche in Stuttgart.
-The car was sold by VoA in Texas, finally being imported into Canada around 1989.
-Car had at least one real race car driver as an owner (Ernie Lader). No evidence he raced it, but he likely drove it hard.
-Car has 55k miles on it, all original as verified by registrations, at least since it came to Canada.
-Engine torn down as part of my restoration. Very little evidence of wear on the crank, bearings, valves, guides etc. In fact we are reusing the rings, they are so good.
-After extensive discussions with Robert Grosse who is going the restoration, we decided on the trombone cooler as a suitable compromise, given the proven state of the engine. He did say if I chose to autox or race, that more cooling would be needed. In which case, I'd leave the trombone where it is and put in jumper lines to a front mounted cooler in a spare chin spoiler just for that purpose and to keep the car original.
-I've source a cooler and spoiler for this purpose and will paint them the same light ivory to match the car. Bolt on and off as needed.
-Temps in Ontario can hit 35C in the summer, typically 3-6 times a year. But in a non-A/C car, I probably wouldn't be driving it anyway at those temps.

Ravi

[69Sman]

I have heard negatives and okay (positive) comments about the trombone. Most comments have been that they are not very good at all and even Porsche knew that. Well, the jury is not out yet. I hope some more people jump in on this thread. I would be less concerned if my rs motor was 100% stock, but it is a 2.8 or 2.9? car and gets pretty hot, rather fast.

Your car is a 2.9. Mine is 2.8, and RUF installed a 906 oil cooler in the front bumper/valance when he restored the car (RSR style.) I would definitely go with a radiator type oil cooler in that RS. Originality be damned. Who cares if an insufficient oil cooler is original to an engine that has been rebuilt to more powerful specs and (probably) needs better cooling?????

[denson]

69 S man trumps on this one! I agree with his thinking and I know he knows my car. I now know it is a 2.9 liter car.

Thank you everyone and my friend 69 S man!