Coolant for my Wankel ;)

[alexdimen]

I've been a mazda rotary fan as long as I've been a car fan and I've built several engines myself.

One of the weaknesses of an older rotary is a thin part of an iron casting that can corrode if the cooling system has been neglected. This leads to a coolant o-ring slipping out and creating the equivalent of a head gasket leak.

The block contains cast iron and aluminum, if that makes a difference.

I have used 50/50 conventional green and most recently 50/50 Prestone multi-vehicle/universal. I always mix with distilled water. I also try to drain and fill at least once a year.

My question is what coolant would you guys recommend for the best corrosion protection?

 

[97prizm]

I have a 1984 rx-7 and use the longlife stuff in the winter and straight water and a coolant additive during the summer racing season.

 

[Kestas]

All antifreezes are designed to protect both cast iron and aluminum. I don't know which protects best against corrosion. I think that depends more on the service interval than the type of antifreeze used.

 

[alexdimen]

The 84 rex's dont have this problem since the coolant o-ring groove is in the aluminum rotor housing rather than the iron side housings.

 

[alexdimen]

I always thought good change intervals were the best corrosion protection. Thanks.

How about Evan's NPG+ waterless coolant? There are a number of people on the rx forum that like that stuff.