How much (volume) of oil does a 13B have in it at any given time versus a comparable piston engine?

The way I understand it the engine only has oil in the rotors and eccentric shaft, which leads me to believe that the actual volume present in the engine (but not combustion area) is lower than that of a piston engine, which has more spots that need to be filled with oil.

By the way, I was thinking about this because I forgot to check my oil and the low oil light came on while driving home, so I figured I'd just change the oil. When that low oil light comes on, the engine really has barely any oil in it (unlike with my piston engine cars).

 

I'm not really sure there's any value in the distinction. If the pickup tube in the oil pan is sucking air, you are doing damage to your engine. I would surely change the oil and monitor the level closely until you have a handle on the rate of consumption.

And welcome to nopistons!

 

I agree there isn't much value in the distinction and I don't know if the car was struggling to suck up oil, but it is more of an engineering curiosity for me now to find the answer. Thanks!

 

The rotary has more oil in the sump than some piston engines. It has less oil in the sump than some piston engines. In every case for every car and every engine the amount is a comprimse. Enough volume to get the car through the warrantee period and a bit beyond. And as little as is possible without getting too many engines killed for lack of oil under hard braking and, or, heavy side loads. The stock rotary steals a bit of crank case oil and drips it into the rotor housings to lubricate the apex seals. So, oil levels must be checked often. For heavy use an extra 1/2 quart will not hurt, as there is no windage problem as in a piston engine.

Lynn E. Hanover