Every Mazda Rotary Engine needs to have a proper cooling system. That includes a strong oil cooling system built for your horsepower output.

Because the oil is pushed through the center of the motor, if you don’t keep those temperatures inline, the water temperature is certainly impacted.

Every performance build at my shop gets an upgraded oil cooling system.

At altitude here in Colorado, cooling engine temps is more critical than at sea level. I have seen temps racing my 13B at sea level to be 180 and then at high plains they tip over 200. Not only does this drop horsepower, it is compounded by the thin air, the impact is that it is harder on the engine and cooling system.

‘Put a fan on it’ is the answer I’ve seen / heard many times. That can help, it is not the only solution and it often times is a band-aid for a much more serious issue. Air needs to flow through coolers (water or oil) at a slow rate to be effective and grab as much heat as possible. There is a reason for having a grill and oftentimes a screen in front of the heat exchanger or cooler. This is designed to slow down the air. It is a known fact that the amount of pressure against a radiator is very small (2-3 lbs of pressure at most). Even with a fan pulling air, the heat transferred is key to keeping the engine cool, meaning below 200 degrees.

We even use steps within the cooling system to keep pressure up and coolant flowing at a consistent / slow rate. Too fast or too slow and there is minimal heat transfer.

I cannot reiterate enough how important this is for horsepower and reliability. In Colorado, we have hot, thin air during most of our track days. Many race cars that come from different parts of the country (at lower elevation) have cooling issues with the long straights (on the race track) keeping their engine temps in their peak zone.

Bottom line: Be prepared and spend the money to keep your engine in the desired heat range of 175-200 degrees, as your temp goes up, the horsepower goes down as the engine has to work harder. I am a fan of Setrab oil coolers, they are tough, they last and they do their job. Proper fitment and air flow in front as well as escaping is critical for any cooler / radiator.

Mazda’s are fortunate that they have ample engine bays for cooling transfer, although I have had to build many shrouds to get air in and make sure that is can get out effectively, they do offer up a lot more flexibility than cars like say the Subaru’s where the engine is right up next to the radiator and the only real way to get air out is to use a hood with vents to get air out for long pulls.

This is where too many rely on fans and they can only do so much, the air has to go somewhere, if it is blocked and doesn’t have an easy path, it will cause overheating. 2-3 laps in an STI and most will start to overheat. Find out more