Can't emphasize enough the need to get a big oil cooler on the car. Yes you may be OK for a while with the stock one or the turbo oil cooler but not long term. The turbo oil cooler is very small in the big picture. Porsches of all types have no tolerence for oil temps above 220*f. So Dave the 240 you saw is asking for trouble. Again you maybe OK for a while but sooner or latter you will have trouble. Having the big cooler will also take stress off the water system. We are not talking about a lot of money here, about $450-$500 for a 19row cooler, sandwich plate, and lines. Alot less than an engine rebuild and if it saves your weekend you won't be wasting money hauling back a dead car.

Really I don't agree that oil at 240 is big issue for these cars. Sure cooler is better, but I have run my car for year in hot temps with and with out a temp gauge and external cooler. 240-260F at the bottom of the pan is common place for 95F+ ambient temps. I bet I ran even hotter with no cooler or temp gauge. The motor has lasted along time like that.


I did have two rod bearing failures, but those were due to specifc problems. First was a broken oil pickup tube due to mis timmed balance shafts. I blew up the entire bottom end on that motor. The second was when I used too much sealant on the girddle and after 3-4 days I spun a bearing. As I tore it down I saw way too much sealant had squeezed out and I am sure clogged up the works.

Other than that I have never had and issue. I do use high quality thick oil and change it often. So far I have 1 day on my last oil change and will run Miller and then change the oil again. 4 days is plenty on oil in warm conditions. When it is cooler I tend to get 6 days from the oil. Remember this is the motor I have 80 races on and it had 140k miles before I rebuilt it to race. It still has the original rings in it as well, but it may finally be getting a little tired.

So while keeping the oil cool is always good I would not panic. Fresh rod bearings and proper oil fill level with a quality thick oil are MUCH more imporant.

We had guy spin rod bearing in one session this past season. He bought a car and used motor and was told many many times to change rod bearings as the were believed to be original.

Well first session out the track he made it about 10 minutes before dreaded rod knock. Turns oil the oil level was at the "low" mark on the dip stick. He never changed the bearings and was running 10w30 oil. Not much to say really.

Oh... if you look around you can probalby get a used 951 system (cooler, lines and oil fiter housing) for $200. I got mine for $120 by getting from a few differnt sources on Rennlist over few months time.

One thing that hasn't been mentioned here is fuel. I know it makes a difference in my WRX. Running higher octane (race fuel) reduces engine temps slightly. Is there any benefit to running higher octane in the 944 engine ? Is there any performance gain, and would the increased efficiency help temps any ? What are your experiences with that ?

Most of us run 91 pump gas or 91 pump gas with a little race fuel mixed in. I a have always run straight pump gas. Remember stock all cars except for the 88 could run on 87 octane. So 91 is pumping it up a little. If you run close to the 10.5:1 compression ratio limit mixing race gas is a good idea. No impact on water temps, but helps prevent any chance of detonation. No impact on hp output either.

Remember the WRX is a turbo car and thus more prone to detontation at higher boost levels. In those cars using race gas allows safer running of more boost.

This has been a great thread. With some very practical information.

Weston suggested Water Wetter, which is explicitly allowed in the rules. Would Evans NPG be allowed as a coolant in 944-spec? If not, is it something that could be considered? It was specifically designed for racing, the motorcycle guys use it and we know how they feel about spills on the track. The non-aqueous propylene glycol they use is non-toxic and environmentaly safe.

Bruce

Coolant rules are NASA CCR rules not 944 spec rules. Read them carefully as I believe only on form of coolant is not allowed. Of course that is the most common.


If I forgot to mention it I use distilled water an 1 full bottle of water wetter. Water is perfect as a coolant medium and the water wetter is in the for its lube properties not cooling aspects.