Frank Barrett

Friends:

My Maxton Rollerskate (one of 50 built in 1990 in Colorado) has a first-generation normally aspirated RX-7 rotary engine. The radiator is cooled by an electric fan controlled by a coolant temp switch. Currently the switch causes the fan to come on when coolant temp hits 210F, and it goes off when the temp drops to about 200F. These temps seem a little high to me. What coolant temps are considered optimal for the RX-7 engine?

Thanks,

Frank

mar3

iTrader: (8)

180 seems optimal....170 and it's too "cold" to burn everything up plus the fan stays on a lot. I'd set the temp to 190 deg F on your fan and you should be OK. I got one of those Mr. Gasket radiator caps that doubles as thermometer and played around with temps for a while. 180 seemed to be the point where the fan wouldn't come on during highway driving, which is what you're shooting for.

The rotary can go to 210 just make sure you've got a good oil in it when that happens.

Mario III

Go48

iTrader: (7)

Here's a data point for you. This is the info on the 13b (2nd gen) thermostat opening and fully open spec. The 12a is essentially the same.

Frank Barrett

Thanks for the advice and info.

Frank

Aaron Cake

iTrader: (1)

Sweet, a Rollerskate!

Make sure to use a stock thermostat. Assuming a stock thermostat, I always set fans to come on at 190F and off at 185F.

mar3

iTrader: (8)

Nice attachment, Go48....full open at 203 F would seem to be a high temperature that the Mazda engineers had no problem with, then.

RotaryRocket88

iTrader: (7)

The FD's fans don't fully switch on until 226F! But exchanging the switch for an FC 203F switch is common among the 3rd gen crowd, and I don't blame them. That's a little warm for my liking, and far above thermostat temp. I believe the RX-8 is the same way, but I'll bet it was done mainly for emissions purposes.