like the title says. i have a 13b out of a85 rx7 and its in my 87 base. today i took my engine out of my car to investigate a coolant and oil mixing problem and found that the rear rotor housing is cracked right next to the rear iron. i was wondering what caused this. its a completely stock engine and the engine/driveline has not been modified at all. no intake or exhaust. ill have pics soon as i disasemble the engine further.

 

Any relevant mods? Nitrous, boost,... Is the trans mounted securely?



Pics of the damage?

 

Same here. But my cracked iron has not affected my compression on the rear rotor(when I ran). The crack is on the top of the rear iron, and goes from the middle to the end(closest to transmission). I don't know how deep it is, but like I stated earlier; not deep enough to cause a problem.-yet.