Brass Tube Oil Cooler?

[SeaDweller]

I have an aftermarket, front fender mounted, fin type oil cooler that seems to be only moderately effective during the Florida summer. I've considered a Carrera type cooler with the fan, but a friend mentioned to me that the best available was the brass tube cooler. I can't believe he's speaking of the loop cooler that I've seen in the past, and he tells me it looks like the door of a jail cell! Are there different types of brass coolers?

If so, is this type cooler as effective, or more effective than the Carrera version with a fan? Will it simply bolt up in the front fender, or is other hardware necessary? Where do you buy one, and how do they compare against the Carrera cooler, expense-wise?

Thanks!

[Jim Sims]

Porsche put these type of coolers on cars for a few years. I don't know if you can get these new any longer. One of my friends put a used one (first he cleaned it up nicely by bead blasting followed by a pressure test) of these tube types on his ROW '79 SC in place of the OEM "trombone" loop (which I was given to install on my '76). He says there was a significant reduction in oil temperatures during his summer runs across the deserts to California. I think the advantage of these types of coolers is less pressure drop due to the tube and tube sheet construction and they are a bit more rugged against debris flung up by the wheels. Cheers, Jim

[gregk1]

Look on ebay and punch #1829303583

[Jadams1]

Here's a picture of mine. It was installed by the PO.

[GB83SC]

I have a stock US 83SC and has this style oil cooler looks like it came in the car this way from the factory, was this the case in 83?
I was allways thinking that I should upgrade to the fin style, I guess I was wrong.
GB83SC

[RarlyL8]

I also am using the multi-tube cooler.
They are less expensive than the Carrera type, but also less effective. The Carrera cooler with a fan is an actual radiator, the multi-tube unit is a heat sink.

[Jim Sims]

Engineer hat on. Actually, both of them are convection heat transfer units. The air side is forced convection when the car is moving or a fan is blowing over them and natural convection (depending on bouyancy of heated air to cause air movement) when the car is motionless or the fan is off. Both have heat sink and radiator aspects to them as do all real heat transfer devices but these are not their primary modes of operation. If this was the case they would be built very differently. The term radiator as commonly used is a real misnomer. It is fun to follow the cool collar threads and I would like to see some real, controlled tests of it using the same car with and without the collar. This would require a dynometer in a wind tunnel or a lot of road tests to get good statistics and is obviously too expensive. I have a prejudice against the cool collar because it looks like it depends on a circulating energy flow (to a certain extent) which is almost always bad unless one is trying to recover heat. I also marvel at the cost of the "Heet Sheet" set; two pieces of flat stainless steel sheet metal, a few standoffs and other fasteners for $70 or more! Engineer hat off. Cheers, Jim

[SeaDweller]

OK, so is it the concensus that the fan cooled Carrera version is more effective than the tube style?

[Wayne 962]

Here is what I have heard:

1- No cooler = not good
2- Loop cooler = better than option 1
3- Brass (European) cooler = very good
4- Carrera cooler = very good, but not quite as good as 4
5- Carrera cooler + Fan = best option, better than 1-4.

Make sense? I'm running a brass oil cooler on my 914-6 because I don't really have the space to mount all of the fan + hardware for the Carrera oil cooler. Plus the Carrera oil cooler is a bit more robust...

-Wayne

[BKOMAR]

JADAMS....is that cooler in the REAR fender? It looks that way in the photo... Mine is in the FRONT RIGHT fender. Wondering which is stock/ correct (?) Brian

[ChrisBennet]

While we're talking about oil coolers I have a couple of questions:
1. Has anyone heard anything about the Kokeln oil cooler? Is is 300% larger and mounts in the same sport as the factory oil cooler.
2. What sort of air flow do you get through that position? Isn't the wheel well a high pressure area (hence the slotted fender on 935's)?
If that cooler is effective it would be an easy install, keep the cooler out of harms way and the car would retain it's stock/"sleeper" appearance.
-Chris

[Jim Sims]

300% larger? What a useless number! 300% larger what? Larger heat transfer area? Wetted perimeters? Oil flow cross-section area? Cost? How about some heat transfer effectiveness data? Pressure drop versus flow rate? The oil passageways look to be rather narrow but they could be okay but only testing would tell. This looks to be a standard "chunk" of gas to liquid crossflow heat exchanger material that has had end tanks with fittings welded to it.

[Jadams1]

Brian, the cooler is in the front right fender. I believe it's the stock setup.

[1980SC]

Our 1980SC euros were the first to come with them from the factory.

-Rob
1980SC euro

[fstar]

Originally posted by Jim Sims
300% larger? What a useless number!

I've gotten alot great advise on this board for which I am thankful but as a new member with 100's of questions I will be careful what I ask if the accepted etiquette is to ridicule someones questions/ideas.

[Jim Sims]

I did not intend to ridicule ChrisBennet. I try not to ridicule questions or comments posted here. I will comment on commercial entities that are "selling" without appropriate consumer or technical information about their goods. I was commenting on the lack of useful information at the referenced website for the Kokeln oil cooler. I went there looking for the facts; there was zip! All it said was 300% larger than the stock cooler. To say 300% larger without referencing how it is larger (or better) is like quoting a number without units. Sounds good but it could actually be a poorer performer than the stock unit. Until there are specifics it is just advertising hype; bigger does not guarantee better steady state heat transfer under the operating condtions in a Porsche 911 wheel well. There are standards for measuring how effectively heat exchangers work; from such data one can tell if the 300% "larger" unit is of any real use in dumping heat. Otherwise, one could end up paying extra money for little or no gain. Currently in my job I'm doing research in boiling heat transfer so I tend to be a little irritated or amused with the advertising "hype" being fed to 911 owners about heat transfer devices. We all want to get rid of heat so badly that we can be easy targets for marginal or useless heat transfer products. My apologies if I offended anyone. Cheers, Jim

[Adam]

I am wondering if anyone's tried the Mazda RX-7 oil cooler in a 911. I've heard somewhere, can't remember where, that it's a good performer. I can get one for $20, so I'd be keen to give it a shot.

Anyone had any experience with these oil coolers?

[Jim Sims]

I've also heard of people using the RX-7 oil coolers in 911's. I don't know how well they work but I heard thay are used because they fit and can be had inexpensively. Jim

[Adam]

Jim,

I'll probably pick one up on Monday, so I'll keep everyone posted on how well/poorly it works. Obviously, it could not be worse than a trombone cooler, so I'm all for it at this stage.

[speeder]

Steve, Welcome to the board and ask all the questions you want. I believe that Jim was if anything ridiculing the manufacturer's claims about their product, not Chris for posting link. He(Jim) is one of the more valuable contributors around here w/ actual engineering training, we have others as well plus a lot of just smart people. This board is a very rich source of technical info, as are the Pelican Tech articles, only etiquet is to search archives for question before posting it in case it has already been discussed at length.

This is one place where good manners abound; we also like to kid around a lot, but most of us get along pretty well. Good luck with your future projects!