Function of the apex seal springs

[Glenn Butcher]

Did you know that the function of the apex seal SPRING is only for starting the engine...

After the engine is started, the apex seals are forced out from the rotor to make contact with the rotor housing - via centrifugal force.

Hence, some compression problems are not because the apex seals are worn, but because the springs eventually flatten out over many years of driving.

Another important point here is that, oil injected into the rotor housings plays an extremely important part when starting the engine (helping with the sealing), but also when the engine is running - for lubrication. This oil is fed from the oil metering pump on a standard rotary engine (or on race cars, it is mixed in with the fuel).


Some of these principals also apply to the Corner Seals and Springs, Side Seals and Springs, Oil Control Rings and Springs.

[MikeLMR]

hmmm interesting , I didn't realise the springs were just for starting, I suppose thats why the classic symptoms of an old rotary is poor starting

I wonder if Mazda have ever experimented with replacing the springs with oil pressure , similar to the hurley direct tip lubrication, but using the pressure to force the seals out for starting, I suppose you have to run an electric oil pump then, or a pressure accumulator to ensure that you had oil pressure from when you first turned the key :)

I bet the rotary could have been one helluva challenger to the piston engine if it ever got any serious R&D money pumped into it, they are much simpler for a start