[RICE RACING]

There is no question at all that its a 13B.

There is also no question at all that it displaces 3.9lt when you count the whole engine.

They are two different things, its only when you are talking equivalence to other types of engines you need to know how much it displaces in time (without repetition)... like for your formulas (all based around 2 stroke and 4 stroke) then you just use 1.3 or 2.6 respectively.

It's the common shared chambers that allow all the 3 rotor faces *per rotor* to do their work (Wankel cycle) which confuses many people & to be honest its not really worth debating as we are all really talking about the same thing.

As you well know when you do a health check on the Wankel (two rotor) you will get in most cases 6 different readings as each chamber is different most times (seal wear, tolerances and rotor cavity disparity) ALL of these go to providing work and a health engine overall and ALL need to be counted you will agree to validate that assessment. Otherwise we would only ever need to measure two faces? *stirring pot*...... You and everyone get what I mean here who has anything ever to do with Wankels.

This is why I count all faces and rate the true capacity of the engine as per its cycle, no matter what type it is. And that is the basis of my points on the topic. So its a 13B that displaces 3.9lt over its Wankel cycle.