Causes of Rotary engine failure

[PercentSevenC]

Originally Posted by NoDOHC

Engine seizes:
I have never seen or heard of a 4-port seizing

I have. Specifically, it was a 12A, but it could happen with any engine. Turned out the oil pickup tube was not properly installed and had actually fallen off into the pan. The e-shaft was basically welded to the rotor bearings as I remember, and there were some nice burn marks on the irons. Freaking Hayes.

Originally Posted by NoDOHC

Apex Seal Failure:
Caused by:
Excessive wear (never seen, but must exist)

I've heard of very high-mileage engines, especially '84+ 13Bs, where the apex seals got worn down so low that they basically "rolled" out of the rotors.

Here's another mode of failure: severe corrosion in the water jacket. In one engine we tore down (in fact, it was the 12A that was in my FB when I first got it), there was corrosion into the spark plug holes in the rotor housings, allowing coolant to enter the combustion chamber. I've also seen some that had corrosion that extended into the coolant seal area. This tends to happen if the engine is run with straight water.