First off, let’s go over some of the basics of rebuilt rotary engines. They are very different from rebuilt piston engines. Rebuilt rotaries often run somewhat poorly upon first startup. How they run later in life is highly dependent on how they get broken in for the first 2000 miles or so. Rotaries are pretty weak as far as starting, power, and response during the breakin period. They build up their power level the more they run, and must be broken in easily to run well later, which is the opposite of what is common knowledge about piston engine rebuilds.

There are 2 basic types of rebuilt rotaries: those that utilize new rotor housings, and those that use old/original ones. These housings perform a similar function to cylinder bores in a piston engine, they provide the smooth surface for compression. The better the surface, the better the engine’s compression and overall strength/smoothness. Rotor housings are not machineable/surfacable, so you either use what you have or get new ones. Many of the more expensive rebuild shops use (or claim to) new rotor housings standard, which reflects the roughly $1000+ pricing difference from my engines’ cost. All of my engines receive good/useable original rotor housings, thus the large savings you receive. These engines still develop to be very strong and reliable, with a life expectancy of 75-100k miles depending on maintenance/driving habits. I have seen final compression numbers reach 120psi, with mazda spec for a NEW rotor housing engine being 125psi.