Spent a stunningly beautiful day at the Summit Point Raceway today. I felt like I had so much grip that I could do no wrong. I don't even remember giving many, if any, point bys, which is saying something since I drive a n/a 944.

The weather was about 70 degrees. I was pushing the car very hard, and I think I am too paranoid since this is my new engine. I pitted in early during the last session when oil temps hit 210 and water hit 225.

If you are racing, or tracking, at what oil and/or water temp should you pit in? I know that I was conservative, but I was worried about the temperature spiking once I shut off the engine.

Also, what are some good tips to improve cooling in the 944s (the system was properly "burped," and I already have a mocol oil cooler).

Thanks,

TD

 

With a 14psi radiator cap, pure water shouldn't boil until 250F. I've know motors to hit 280F without hurting anything, but I wouldn't want to try with mine. I tend to watch my coolant if it gets over 210F while underway, and shut it down at 230F. Oil temp of 210F with water at 225F sounds low. I look for oil to be around 230F.
Note: A large part of my experience is with sportbike motors, so 944 numbers may be a little different, though I doubt the difference is big.

 

A bit high, Todd;

I did see about 260 on mine once when the t-stat stuck shut. No ill effects... thank goodness. My car rarely goes over 200 water temp, and it has very little fancy about it at all. I don't know about oil since I have never hooked up my oil temp gauge. Well... I always said I would "when I had to drop the pan..."... but I have never HAD to. Dang car just keeps going!!!

I have only one mod to the cooling system. I openned up the core support right behind the bumper bar and increaed the direct airflow to the rad by about 20-30%. That dropped me 10-15 degrees right there.

Some of the heat may be because it is a bit tight yet. Hopefully your cooler setup is not restricting flow. Something very few think of when doing such. I'd change the cap just to make sure. A surprising number of cooling problems end up being that.

Report back!

 

Thanks guys. Today, I didn't exceed 210 water and 190 oil, although it was a little cooler (probably about 65 degrees). I was pushing the car very hard.

John, I think that airflow may indeed be playing a roll. The engine is rebuilt, the radiator was professionally cleaned, all the hoses are new, and the thermostat is new, so I cannot imagine it is anything else than mechanical. Do you happen to have any pictures of what you have done? I am assuming ventilation is open for SCCA, PCA and 44 spec/cup rules.

TD

 

always use an OE car, aftermarket does not "fit". I've seen a few with issues about aftermarket caps.

 

Thanks guys. I will try a new cap as well. I can keep the current one as a spare.