Tampa 928s

86 S/C
I picked up a used radiator that does not have the oil cooler, I heard if you use an external cooler this would work better to keep the temps down on my S/C.
Any suggestions?

AO

Go for it.

pjg

I would think the temps would be more stable with the radiator oil cooler, and its plug and play. The air cooler needs to be much larger to perform as well, will need new plumbing and a place to mount it.

Tampa 928s

I spoke to Fabio this A.M. and he told me the radiator is reversible, and he is correct.
I have an other issue that I need to address the aftermarket Temp sensor that is used for my 4-Fans keeps going bad, I assume from the heat. Can I wire in the lower Temp sensor to control this? I now have the ability to mount my extra Temp sensor on the top of the Radiator would this be a better place due to it being a return on the coolant?

Tampa 928s

I am testing the Fan turn on switch I have two:

One: 3 Ohms when heated with heat gun goes to 0 Ohms
Two: Inf Ohms when heated with heat gun stays at inf Ohms

One must be bad or maybe both; should I not see Inf ohms until it heats up then 0 Ohms?

Fabio421

The in-radiator oil cooler is good in one regard. It will allow the oil to warm faster to operating temperature but once that occurs, it isn't better in any regard. Especially if you are running a modified ( supercharged ) engine with half of the radiator air flow blocked by the SC airbox. Eliminating the cooler in the radiator side tank and using an external engine oil cooler will reduce the load on the engine cooling system. This is desireable in this case becasue that supercharged car will run hot anytime it is idling in traffic with the AC on. You can get external engine oil coolers with thermostatic bypass which will let the oil bypass the cooler until it reaches operating temperature. There are many good ones on the market. http://www.jegs.com/i/Derale/259/15651/10002/-1

pjg

Don't you need to be moving for the air cooler to cool the oil ? If you are stuck in traffic how much cooling are you getting with the air cooler ? The water pump and radiator are always cooling.

In 1986 Porsche broke the speed record at the Arizona salt flats with a stock 928 @171 MPH does not get more extreme than that.

http://www.youtube.com/watch?v=fsxQZ_H96aY

Comparing air and water, air has vastly lower heat capacity per gram and per volume (4000) and less than a tenth the conductivity, but also much lower viscosity (about 200 times lower: 17.4 × 10−6 Paˇs for air vs 8.94 × 10−4 Paˇs for water). Continuing the calculation from two paragraphs above, air cooling needs ten times of the surface area, therefore the fins, and air needs 2000 times the flow velocity and thus a recirculating air fan needs ten times the power of a recirculating water pump. Moving heat from the cylinder to a large surface area for air cooling can present problems such as difficulties manufacturing the shapes needed for good heat transfer and the space needed for free flow of a large volume of air. Water boils at about the same temperature desired for engine cooling. This has the advantage that it absorbs a great deal of energy with very little rise in temperature (called heat of vaporization), which is good for keeping things cool, especially for passing one stream of coolant over several hot objects and achieving uniform temperature. In contrast, passing air over several hot objects in series warms the air at each step, so the first may be over-cooled and the last under-cooled.

David L. Lutz

You can use the lower Temp Sensor on the Rad, but I am planning on replacing that sensor with part # 951 606 481 00. This thermoswitch is a 85/93 degree 2 stage switch. I was going to kick the 4 10" fans on first at 85 degrees and have the 93 degree leg kick on the 16" pusher fan. Using an aftermarket controller.

Check this thread out for further details.

https://rennlist.com/forums/928-foru...g-fan-kit.html

Hope this helps

IcemanG17

since your 928 is boosted its a VERY good idea to run an oil cooler....the stock oil cooler fittings already have a thermostat built in, so that will work well with any aftermarket cooler.....

some like the in radiator cooler, since it has the added benefit of helping the oil warm up.....

Here is my thinking....the radiator in most 928's is stressed enough...taking the extra heat from the oil or trans oil out of it will make it work that much better....for example my race 84 only uses the radiator for water.....the auto trans is cooled by a huge 1qt cooler and the oil is not cooled at all.....this is fine for my low HP application..but I would NOT go any higher than say 250 crank HP without an oil cooler...

Tampa 928s

Good info, remember I have an oil line into my supercharger so I need to see if a kit will work.
I like the two temp switch option with relays, one for my condenser fan and the other for the four rear fans.

Tampa 928s

https://rennlist.com/forums/928-foru...fan-kit-4.html

Trying to find this locally the search on the parts sites do not come up. Does anyone know the specify model it fits?

Fabio421

I know you want to show you are the smartest guy in the room but your post shows that you don't even understand what we are talking about. The in tank oil cooler is adding BTU's to the water in in the cooling system that is already struggling. Getting the oil cooler out of the radiator will allow the engine to run cooler. If the salt flats car had a supercharger and airbox plocking half of the radiator airflow and was left idling on the salt flats w/ the A/C running, it might have run a little hot too. The car the OP posted about doesn't have a problem while its moving at a reasonable speed, only when idling with the A/C on. Lastly, no one said we hd to mount the external oil cooler in front of the radiator. There is plenty of room in the fender to mount the cooler and even a dedicated fan if desired.

pjg

Not trying to look smart, if the air cooler works go for it.

Tampa 928s

Did anyone come up with a applicable model and year so I can get the Temp switch from the local parts house.
I searched Pep Boys, Auto Zone, Etc web sites and nothing returns under the part numbers shown.

I like the oil cooler idea; now where to mount it!

Fabio421

Are you talking about this one?

If so here is one for $12. http://www.allzim.com/acatalog/Fan_S..._S_S2_968.html

There are also a few other options with different temp settings.

I hope this helps. If not, here is the listing for the temp switches at NAPA but they are more expensive.
http://www.napaonline.com/Search/Res...+50062+2062033