Carrera oil cooler fan on earlier cooler

sbmackie · 01-23-2008, 09:19 AM

Greetings,
My SC has the early Carrera cooler (28 row copper) in place of the trombone. The lower right bumper is notched.

Can I install the fan from the later Carrera cooler without a lot of surgery? I have a spare switch from the removed headlight squirters on the dash.

Thanks
Scott

javadog · 01-23-2008, 10:54 AM

Scott,

The fan attaches to the Carrera cooler at the edges. The 28 tube cooler doesn't have the same edges, so it's not a bolt-on deal. You'll have to farbricate some brackets.

JR

ljowdy · 01-23-2008, 11:37 AM

From what I've gathered, the fan on the Carrera oil cooler is not the best and not designed to operate for long periods of time. Apparently, the sensor in the cooler is set at 250 degree's and if you use the BMW 210 degree sensor it will eventually cause premature detonation of the fan. I'd suggest you go to your local electronics store and look around for a good 12 volt fan and use that instead of the Porsche fan.

When I installed my 3.2 engine in my 1973 911, I also installed the Carrera cooler and added the BMW sensor. I ran everything through a relay and added an optional on/off switch in case the sensor failed.

When and if this fan takes a dump, I'll be at my local electronics store looking for a good permanent magnet fan.

sbmackie · 01-23-2008, 08:40 PM

Ok, a bit of thread creep, but what about the $95 black scoops that replace a reflector on the right side? Any effectiveness?

sbm

Porsche virgin · 01-24-2008, 05:04 AM

Quote:

Originally Posted by sbmackie

Greetings,
My SC has the early Carrera cooler (28 row copper) in place of the trombone. The lower right bumper is notched.

Can I install the fan from the later Carrera cooler without a lot of surgery? I have a spare switch from the removed headlight squirters on the dash.

Thanks
Scott

Take a look at this thread.

Fan on a 28 tube brass oil cooler?

I'm probably going to put a fan on my 28-row cooler this spring, with a manual on/off switch, for those times I get stuck in traffic and there is no air passing over the cooler.

surflvr911sc · surflvr911sc's Garage

Elephant Racing sell a fan kit that should work w/ a 28 row.

Elephant Racing Fans

911pcars · 01-24-2008, 09:26 AM

Spal makes several fans that fit this category and are used by many for this application. Around 5-6" dia., push type.

Hmmm. That's the first I've heard about the longevity of the Porsche fan.

Sherwood

sbmackie · 01-24-2008, 12:03 PM

Thanks for all the input. Car coming out of shop with ducktail on it. I'll get some kind of fan to go with it come spring.

sbm

GMR911 · 01-24-2008, 06:36 PM

I have a 6.5 inch spal fan on my 28 row cooler. It is run by a manual switch on my dash. When the car hits about 210 degrees I will turn on the fan and it will lower the temps to about 200 within about 5-10 minutes, Jerry

ninesixfour · 03-06-2008, 08:26 AM

Quote:

Originally Posted by GMR911

I have a 6.5 inch spal fan on my 28 row cooler. It is run by a manual switch on my dash. When the car hits about 210 degrees I will turn on the fan and it will lower the temps to about 200 within about 5-10 minutes, Jerry

Will it go any lower than that?

rusnak · 12:06 PM

I think the tubed oil cooler can benefit from a fan, but not as much as a finned cooler. I would seriously consider getting a finned cooler, such as the ones that came on the 3.2 911s from 1985 on.

I have an '84 with a finned cooler that originally came without the fan. I used to get oil temps above 250F regularly in the summer, sometimes 260F. After I installed the factory Porsche fan, I rarely get temps above 240F, even with the AC on and sitting in the drive through at a local Burger King. I mention this because I personally feel that the factory fan works better than most aftermarket fans (I've used 2 other fans). I installed it in 2002, and it's still working. The key is the manual override. If you are expecting hot weather, turn on the fan when your oil temp is still 160F. The fan will prevent the oil from getting hot. Once it gets hot, it takes a long time to make the oil lose it's heat. It's easier to keep it cooler than to cool it once it gets hot.

I also have the black cooling scoop. I installed it back in 2000 (eight years ago). As is, out of the box, the scoop is worthless. The reason is that there is no internal baffling to direct the air. All you are doing is creating drag, and hoping that the air finds its way through the cooler on its own, which is pure fantasy. You have to install an internal baffle and duct the air right on to the cooler to force it through the cooling fins. I did this, and found that the scoop works somewhat when configured this way.

Porsche virgin · 03-06-2008, 12:24 PM

Quote:

Originally Posted by rusnak

I think the tubed oil cooler can benefit from a fan, but not as much as a finned cooler. I would seriously consider getting a finned cooler, such as the ones that came on the 3.2 911s from 1985 on.

I agree totally, but the (expensive) Elephant Racing fan and installation kit costs $168. A fender-mounted oil cooler with the accessories (but no fan) is another nearly $800.

If the car sees limited stop-and-go traffic action, a fan on the 28-row cooler makes a lot of sense.

cmcfaul · cmcfaul's Garage

question, my car sees 250+ temps on the track only with a Mocal fined cooler. Would a fan help?

Thanks,

Chris
73 911e

ninesixfour · 03-06-2008, 05:54 PM

Unless there's a traffic jam on the interstate while en route to the track my car sees zero stop and go traffic and little street use period. I have a 28 row brass cooler that I've just gotten working properly since fixing a completely crimped oil line I found. With the crimped oil line letting very little oil to the cooler I was seeing 260 degrees at the track in 50 degree weather.
I'm hoping now that the cooler is getting oil the temps will come down but the one test drive I've done seems to indicate it isn't going to come down as much as I'd like which is why I'm considering a fan. Looking at the front bumper area I can't see how much air is getting to the cooler right now so it seems like a fan would help but the question is how much. I plan on making it manual use only and I'll just turn it on at the beginning of each track session.
Unfortunately the threads I've read on this seem to lean towards the fan not helping a 28 row cooler much. Is the Carrera cooler that much better? Changing nothing else, how much of a change in temp would a Carrera cooler provide over a brass one? If I were to get one it would be tempting to just run it in series with the brass one. Problem is where do you relocate that emissions canister?

Porsche virgin · 03-07-2008, 08:52 AM

I would think that a fan wouldn't be useful at speed on the track. It would seem to be better (and I am certainly no expert on this) to have the cooler get more fresh air running through it either by putting it in the center below the bumper or taking our your passenger-side headlight and drilling some holes. (I think there is a thread around here on the exact process.)

rusnak · 03-07-2008, 09:04 AM

Bruce Anderson's 911 Performance Handbook, first or second edition addresses this issue actually quite well.

He describes the brass tubed cooler as more of a heat sink. It works better than the "trombone" looped cooler, but less well than the later finned cooler. The finned cooler got a fan added to help at slow speeds in the USA. In Germany with their cooler weather, and wide open autobahn, a fan is not needed as much. Also, he describes the best setup as one with no fan, in which a cooler is added at the front of the car with ducting to force air through the cooler when the car is moving forward. The RS style, or Ruf style cooler in the front bumper is considered the ultimate external oil cooler setup, with the finned/ fan oil cooler in the right front fender being not as effective, but perhaps more compatible with a street style impact bumper that may need to save your life someday.

I think since your 911 is pretty much a track car, you might want to go hunting for a fiberglass front end that will allow you to run a front mounted cooler such as a Lemke or Tubatrol or Mocal. There has been a ton of research on this, with some guys using Mazda oil coolers and stuff. The key is airflow. Air needs to be forced through the cooler, and the cooler needs the surface area that fins provide to shed heat into the passing air.

911Freak · 09:52 AM

Another very effective means of controling oil temps which hasn't been mentioned yet is the use of 2 oil coolers...Keep your 28 row and add another in the other fender, using cross over oil lines, then as mentioned above for track days remove your headlights, and drill holes in your head light bucket so that air can travel to the coolers directly....
I know of many 911sc using this setup even with just 1 oil cooler and it is very effective...

patkeefe · 03-07-2008, 10:41 AM

A fan on a 28 tube cooler will do next to nothing. Why? Because it has no fins for effective heat transfer. If you have a finned oil cooler, then a fan is very effective, provided you duct the pressurized air from the fan directly over the cooler.
Pat

Porsche virgin · 03-07-2008, 11:03 AM

Quote:

Originally Posted by patkeefe

A fan on a 28 tube cooler will do next to nothing. Why? Because it has no fins for effective heat transfer.
Pat

Then why do my oil temps decline when the car is moving as opposed to sitting still? Isn't having some air move over the tubes preferable to having none?

javadog · 03-07-2008, 11:16 AM

Of course. Saying that a fan will do nothing for a 28 tube cooler is not quite right. It may have less surface area than a Carrera cooler but it still has quite a bit.

JR