oil for racing

I am going to be taking my old 89 nissan centra 1.6L to the dirt track for some racing. The engine will be completely stock, and im not sure what type of oil to use. The engine should get a good beating out there and I am in the chicago area so it will be pretty hot at most times. I don't want the constant reving of the engine and the wrong oil to cause any problems. I was just going to use 10w30, but should I go thicker or to a lighter 5w type of oil? I have seen 20w50 racing oil, but labled "only for performance engines", wich mine is definately not. Thank you for any input.

Synthetic oil would be a good move, synthetics have a lot higher tolerance to heat and give better wear protection. Just go with plain Mobil 1 10W30 or Castrol Syntec 10W30.

Thanks, I never thought of using syntgetic, I always heard that switching to synthetic in a high mileage car was not a good idea, but if I were to try it, this would be the car to try it on, its immortal.

I have nothing to gain from telling you that AMSOIL is my recommendation for the oil to use if you really care about your motor. It scores better than most synthetics in both wear and temperature testing. However, if you have a stock motor, then it might not be worth your effort to get it when you can find Mobil1 everywhere. When you start getting into synthetic oils, you're looking at serious resistance to the abuse of high performance motors (forced induction, high rpms, etc.)

Thanks, I never thought of using syntgetic, I always heard that switching to synthetic in a high mileage car was not a good idea, but if I were to try it, this would be the car to try it on, its immortal.

Conventional oils leave wax in the oil pan. Using a synthetic from day 1 will prevent this, but using a synthetic after years of conventional oil use won't remove this. Maybe there's some kind of flush that you could do beforehand to take full advantage of the synthetic? That wax buildup can provide a thermal barrier that can affect the engine cooling effects of oil. Most synthetics on the market today are perfectly compatible with conventional oils, so I wouldn't worry TOO much if I were you. You'll gain the improved temperature and wear characteristics if you switch, but something worth mentioning is how any change in oil can cause leaks. Maybe someone who knows more than I do can fill in the gaps here, but I think the wetting ability of a synthetic allows it to seep in smaller cracks.