Maximizing Trombone Oil Cooler

[SpenceRx]

I was thinking about ways to maximize the trombone cooler efficiency until I can upgrade to a proper solution. I’m mostly worried about getting stuck in traffic during unexpected roadworks on hot summer days. Thinking of starting by cleaning it really well to get the grime off of it. Apparently it should shine up nicely not be black. Other ideas:

1) What about wrapping some of it in copper mesh to increase the surface area?
2) repurpose headlight washers to spray water on the trombone

I know this is a futile exercise when there are other better solutions out there but curious if others have hacked something together.

[HarryD]

What size motor is in your car? Do you have factory hard lines or flex lines? Do you have an overheating problem now?

My 1973.5 with a 140 hp 2.4L motor only needs external cooling when I am on the track during the summer. I installed factory hard lines and a trombone and it is adequate for me.

[HarryD]

I just saw your thread on the car (1977 911S).

Keep in mind that even the SC's (with more power) came with only a trombone which the Porsche engineers deemed adequate.

Keep an eye on the temperatures to determine your next move.

[Nditiz1]

Spencer don't be worried, some 2.7s didn't even come from the factory with an external cooler and they were still running fine. My 76 has one because I installed the lines and a trombone. In hot weather it doesn't come close to 210 unless I push it hard up hills. Enjoy the ride more and worry less about the engine overheating, especially if it has been rebuilt.

[SpenceRx]

Good advice here! Thanks. I am overly worried. It has been rebuilt which is nice.

[smadsen]

The trombone cooler works fine in northern Germany.

[Fixer]

Maximize the trombone cooler by replacing it with a Carrera cooler.

A cooler engine will last forever.

Next oil change simply change it out, it's not difficult.

[chrismorse]

I remember riding with my Dad in his 74 coupe With AC, in Santa Barbara on a 80 degree day. We were going through the hills, not very quickly, with the AC on and the temp was alarmingly hitting 260
someone had told him that was ok???

Years later, he passes on the car to me and one of the first things I did was remove the AC so i could run the recently acquired thermostat, lines and carerra cooler.
No More high temps.
IIRC, Elephant has a graph showing the relationship between oil temperatures and engine life.
c

[Fixer]

Re oil temp and engine life, it's common sense.
Oil thins way out at high temps.

[Bill Verburg]

Originally Posted by SpenceRx

I was thinking about ways to maximize the trombone cooler efficiency until I can upgrade to a proper solution. I’m mostly worried about getting stuck in traffic during unexpected roadworks on hot summer days. Thinking of starting by cleaning it really well to get the grime off of it. Apparently it should shine up nicely not be black. Other ideas:

1) What about wrapping some of it in copper mesh to increase the surface area?
2) repurpose headlight washers to spray water on the trombone

I know this is a futile exercise when there are other better solutions out there but curious if others have hacked something together.

You could braise copper strips between the tubes, copper pipe hanging strap would be a workable material.

The key will be the contact between the trombone and the copper, The more intimate and solid the better for heat transfer.

any extra air flow will be a plus

[Funracer]

You can buy one of those oil cooler air scoops that replaces the right front corner light and directs air to the trombone.
Also 86 and later I think front bumper has a cutout underneath on the corner to allow more air into that area.
Check your long oil lines under the right side sill. They are often partly crushed (like mine) and may reduce the oil flow to the cooler.
I have even heard of moving the horns to the left fender or replacing the long trumpets with hockey puck style horns to allow more uninterrupted airflow through the fender.

Other than the air scoop which is relatively cheap and super easy, doing the other three is likely harder than just putting in a Carrera cooler. I installed one (without the fan) over this last winter. Once you have all the bits and pieces assembled its not too bad of a project with plenty of online help. On top of that it works really well while the car is moving.

As for the fan, always better to have it than not. No traffic where I live so I left it out.

Good luck

[Fixer]

Addition of a fan to a trombone is a wasted effort. Install a Carrera cooler.

[EC900]

SpenceRx - as I mentioned I do not have a trombone on my 2.7 & mostly city drives during summer, stop light to stop light and it’s rare to get overly hot like above 240°, maybe creeps up another 10° if I recall but will drop down as air moves. Highway is a whole different experience with constant temps around 190° of course this is on the dash gauge that may or may not be a guaranteed accurate and calibrated instrument after 47 yrs.

For what it worth, the operating temp should be 180° (for checking oil level) but under driving it’s perfectly normal to reach 220° and above, remember the engine has to get hot to burn off any condensation in the oil.

If your new-to-you 911 was a daily driver in decent shape, clean engine, valves adjusted, regular service, good gas, etc. then you should be confident its ability to operate adequately.

You might very well be overthinking and the best way around this is to drive it in the manner you intend to make your trip, monitor without obsessing, let it idle too so you can see some actual results of where the dash gauge is registering.

But in case you don’t have your manual on hand, here’s some info …

[HarryD]

Some great advice from Steve Weiner on this topic.

Originally Posted by Steve@Rennsport

If I can add to Dan's post,....

JMHO,.......Thermostats open between 180-185 degF and I like to see these engines run between 190 & 220 degF. The 220 mark is the tiny hash mark on the gauge face directly across from "Normal" on the graphic. 248 is too damned hot (paraphrasing my buddy Bruce Anderson) and not conducive to maximum engine longevity.

Modern synthetic oils function well above 275 degF, however the propensity for oil leaks rises exponentially when the engine operates in these high temperatures. For that reason alone, I like too maintain operating temps below 200 to maintain the integrity of all the gaskets, seals, and O-rings.

Performance really begins to fall off when oil temps rise above 210 degF so thats something to consider due to high cylinder head temps and reduced volumetric efficiency.

My advice to "ramonesfreak" would be to use a 15w-40 in hot weather and at those temperatures, leaving the lighter oils for water-cooled cars. Overfilled oil systems result in high oil temps so make sure you are making any dipstick decisions at operating temps (above 190 degF).

[Fixer]

A trombone "cooler" is more or less just a means to turn the oil back to the engine.

The entire length of pipe each way does the cooling same as the trombone.

Remove it and install a Carrera cooler with fan

[Nditiz1]

Originally Posted by Fixer

A trombone "cooler" is more or less just a means to turn the oil back to the engine.

The entire length of pipe each way does the cooling same as the trombone.

Remove it and install a Carrera cooler with fan

This is a very incorrect statement

[unclebilly]

Here is one very cost effective option I did 15 years ago… still working fine.

https://forums.pelicanparts.com/porsche-911-technical-forum/492336-budget-oil-cooling-myth-dispelled.html

[Fixer]

Originally Posted by Nditiz1

This is a very incorrect statement

It's absolutely correct. It's just a pipe like those running to and from it.

It's simply a means to turn the oil around..

Explain to me how I'm wrong. I'll wait lol.

[unclebilly]

Originally Posted by Fixer

It's absolutely correct. It's just a pipe like those running to and from it.

It's simply a means to turn the oil around..

Explain to me how I'm wrong. I'll wait lol.

Well in addition to being a u shaped pipe that returns oil to the line that carries oil back to the oil tank, it is also a heat exchanger that helps to cool the oil.

[Fixer]

Originally Posted by unclebilly

Well in addition to being a u shaped pipe that returns oil to the line that carries oil back to the oil tank, it is also a heat exchanger that helps to cool the oil.

The entire length of pipe cools, the trombone does very little.

Would you looky here:



I thought everyone knew this. I have 5 hanging in the rafters of my shop. This information is also in Paul Frere's book PORSCHE 911 STORY

https://www.pelicanparts.com/techarticles/911_carrera_oil_cooler/911_carrera_oil_cooler.htm

Common sense folks. I wish I could find a mic dropping emoji.

Matt